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PCA8574APW,118
I/O Expander, 8bit, 400 kHz, I2C, SMBus, 2.3 V, 5.5 V, TSSOP
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- Manufacturer: NXP
- Product type: I/O Expanders
- No. of Pins: 16Pins
- No. of I/O's: 8I/O's
- Bus Frequency: 400kHz
- IC Interface Type: I2C, SMBus
- Chip Configuration: 8bit
- Supply Voltage Max: 5.5V
- Supply Voltage Min: 2.3V
- Interface Case Style: TSSOP
| Delivery and price | |
|---|---|
| Units per pack | 100 |
| Price | 1.24 € |
| Current stock | 1000+ |
| Lead time | 7 days |
Datasheet
## **PCA8574; PCA8574A**
## **Remote 8-bit I/O expander for I[2] C-bus with interrupt**
**Rev. 3 — 3 June 2013 Product data sheet**
## **1. General description**
The PCA8574/74A provides general-purpose remote I/O expansion via the two-wire bidirectional I[2] C-bus (serial clock (SCL), serial data (SDA)).
The devices consist of eight quasi-bidirectional ports, 400 kHz I[2] C-bus interface, three hardware address inputs and interrupt output operating between 2.3 V and 5.5 V. The quasi-bidirectional port can be independently assigned as an input to monitor interrupt status or keypads, or as an output to activate indicator devices such as LEDs. The system master can read from the input port or write to the output port through a single register.
The low current consumption of 4.5 A (typical, static) is great for mobile applications and the latched output ports have 25 mA high current sink drive capability for directly driving LEDs.
The PCA8574 and PCA8574A are identical, except for the different fixed portion of the slave address. The three hardware address pins allow eight of each device to be on the same I[2] C-bus, so there can be up to 16 of these I/O expanders PCA8574/74A together on the same I[2] C-bus, supporting up to 128 I/Os (for example, 128 LEDs).
The active LOW open-drain interrupt output (INT) can be connected to the interrupt logic of the microcontroller and is activated when any input state differs from its corresponding input port register state. It is used to indicate to the microcontroller that an input state has changed and the device needs to be interrogated without the microcontroller continuously polling the input register via the I[2] C-bus.
The internal Power-On Reset (POR) initializes the I/Os as inputs with a weak internal pull-up 100 A current source.
## **2. Features and benefits**
- I[2] C-bus to parallel port expander
- 400 kHz I[2] C-bus interface (Fast-mode I[2] C-bus)
- Operating supply voltage 2.3 V to 5.5 V with 5.5 V tolerant I/Os held to VDD with 100 A current source
- 8-bit remote I/O pins that default to inputs at power-up
- Latched outputs with 25 mA sink capability for directly driving LEDs
- Total package sink capability of 200 mA
- Active LOW open-drain interrupt output
- Eight programmable slave addresses using three address pins
- Low standby current (4.5 A typical)
- 40 C to +85 C operation
**==> picture [172 x 101] intentionally omitted <==**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
- ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per JESD22-C101
- Latch-up testing is done to JEDEC standard JESD78 which exceeds 100 mA
- Packages offered: SO16, TSSOP16, SSOP20
## **3. Applications**
- LED signs and displays
- Servers
- Key pads
- Industrial control
- Medical equipment
- PLCs
- Cellular telephones
- Mobile devices
- Gaming machines
- Instrumentation and test measurement
## **4. Ordering information**
## **Table 1. Ordering information**
|**Type number**|**Topside mark**|**Package**|**Package**|**Package**|
|---|---|---|---|---|
|||**Name**|**Description**|**Version**|
|PCA8574~~D~~[1]<br>PCA8574D||SO16<br>plastic small outline package; 16 leads; body width 7.5 mm<br>SOT162-1|||
|PCA8574A~~D~~[2]<br>PCA8574AD|||||
|PCA8574PW<br>PCA8574||TSSOP16<br>plastic thin shrink small outline package; 16 leads;<br>body width 4.4 mm<br>SOT403-1|||
|PCA8574APW<br>PA8574A|||||
|PCA8574TS[3]<br>PCA8574||SSOP20<br>plastic shrink small outline package; 20 leads;<br>body width 4.4 mm<br>SOT266-1|||
|PCA8574ATS[4]<br>PA8574A|||||
- [1] PCA8574D drop-in replacement for PCF8574T/3.
- [2] PCA8574AD drop-in replacement for PCF8574AT/3.
- [3] PCA8574TS drop-in replacement for PCF8574TS/3.
- [4] PCA8574ATS drop-in replacement for PCF8574ATS/3.
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A **Product data sheet**
All information provided in this document is subject to legal disclaimers. **Rev. 3 — 3 June 2013**
**2 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **4.1 Ordering options**
**Table 2. Ordering options**
|**Type number**|**Orderable**<br>**part number**<br>**Package**<br>**Packing method**<br>**Minimum**<br>**order**<br>**quantity**<br>**Temperature range**|
|---|---|
|PCA8574D|PCA8574D,512<br>SO16<br>Standard marking * tube dry pack<br>1920<br>Tamb=40C to +85C|
||PCA8574D,518<br>SO16<br>Reel 13” Q1/T1<br>*standard mark SMD dry pack<br>1000<br>Tamb=40C to +85C|
|PCA8574AD|PCA8574AD,512<br>SO16<br>Standard marking * tube dry pack<br>1920<br>Tamb=40C to +85C|
||PCA8574AD,518<br>SO16<br>Reel 13” Q1/T1<br>*standard mark SMD dry pack<br>1000<br>Tamb=40C to +85C|
|PCA8574PW|PCA8574PW,112<br>TSSOP16<br>Standard marking<br>* IC’s tube - DSC bulk pack<br>2400<br>Tamb=40C to +85C|
||PCA8574PW,118<br>TSSOP16<br>Reel 13” Q1/T1<br>*standard mark SMD<br>2500<br>Tamb=40C to +85C|
|PCA8574APW|PCA8574APW,112<br>TSSOP16<br>Standard marking<br>* IC’s tube - DSC bulk pack<br>2400<br>Tamb=40C to +85C|
||PCA8574APW,118<br>TSSOP16<br>Reel 13” Q1/T1<br>*standard mark SMD<br>2500<br>Tamb=40C to +85C|
|PCA8574TS|PCA8574TS,112<br>SSOP20<br>Standard marking<br>* IC’s tube - DSC bulk pack<br>1350<br>Tamb=40C to +85C|
||PCA8574TS,118<br>SSOP20<br>Reel 13” Q1/T1<br>*standard mark SMD<br>2500<br>Tamb=40C to +85C|
|PCA8574ATS|PCA8574ATS,112<br>SSOP20<br>Standard marking<br>* IC’s tube - DSC bulk pack<br>1350<br>Tamb=40C to +85C|
||PCA8574ATS,118<br>SSOP20<br>Reel 13” Q1/T1<br>*standard mark SMD<br>2500<br>Tamb=40C to +85C|
## **5. Block diagram**
**==> picture [353 x 191] intentionally omitted <==**
**----- Start of picture text -----**<br>
PCA8574<br>PCA8574A<br>INTERRUPT<br>INT LP FILTER<br>LOGIC<br>A0<br>A1<br>A2<br>SCL INPUT I [2] C-BUS SHIFT I/O<br>FILTER CONTROL REGISTER 8 BITS PORT P0 to P7<br>SDA<br>write pulse<br>read pulse<br>POWER-ON<br>VDD RESET<br>VSS<br>002aac677<br>**----- End of picture text -----**<br>
**Fig 1. Block diagram**
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A **Product data sheet**
**Rev. 3 — 3 June 2013**
**3 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
## **Remote 8-bit I/O expander for I[2] C-bus with interrupt**
**==> picture [350 x 178] intentionally omitted <==**
**----- Start of picture text -----**<br>
VDD<br>write pulse IOH<br>100 µA<br>Itrt(pu)<br>data from Shift Register D Q<br>FF<br>P0 to P7<br>CI IOL<br>S<br>power-on reset VSS<br>D Q<br>FF<br>read pulse CI<br>S<br>to interrupt logic<br>data to Shift Register<br>002aah521<br>**----- End of picture text -----**<br>
**Fig 2. Simplified schematic diagram of P0 to P7**
## **6. Pinning information**
## **6.1 Pinning**
**==> picture [497 x 188] intentionally omitted <==**
**----- Start of picture text -----**<br>
INT 1 20 P7<br>SCL 2 19 P6<br>A0 1 16 VDD A0 1 16 VDD n.c. 3 18 n.c.<br>A1 2 15 SDA A1 2 15 SDA SDA 4 17 P5<br>A2 3 14 SCL A2 3 14 SCL VDD 5 PCA8574TS 16 P4<br>P0 4 PCA8574D 13 INT P0 4 PCA8574PW 13 INT A0 6 PCA8574ATS 15 VSS<br>P1 5 PCA8574AD 12 P7 P1 5 PCA8574APW 12 P7 A1 7 14 P3<br>P2 6 11 P6 P2 6 11 P6 n.c. 8 13 n.c.<br>P3 7 10 P5 P3 7 10 P5 A2 9 12 P2<br>VSS 8 9 P4 VSS 8 9 P4 P0 10 11 P1<br>002aac678 002aac941 002aac680<br>Fig 3. Pin configuration for SO16 Fig 4. Pin configuration for Fig 5. Pin configuration for<br>TSSOP16 SSOP20<br>**----- End of picture text -----**<br>
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A
All information provided in this document is subject to legal disclaimers.
**Product data sheet**
**Rev. 3 — 3 June 2013**
**4 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **6.2 Pin description**
|**Table 3.**<br>|**Pin description**|**Pin description**|**Pin description**|
|---|---|---|---|
|**Symbol**|**Pin**||**Description**|
||**DIP16, SO16**|**SSOP20**||
|A0|1<br>6<br>address input 0|||
|A1|2<br>7<br>address input 1|||
|A2|3<br>9<br>address input 2|||
|P0|4<br>10<br>quasi-bidirectional I/O 0|||
|P1|5<br>11<br>quasi-bidirectional I/O 1|||
|P2|6<br>12<br>quasi-bidirectional I/O 2|||
|P3|7<br>14<br>quasi-bidirectional I/O 3|||
|VSS|8<br>15<br>supply ground|||
|P4|9<br>16<br>quasi-bidirectional I/O 4|||
|P5|10<br>17<br>quasi-bidirectional I/O 5|||
|P6|11<br>19<br>quasi-bidirectional I/O 6|||
|P7|12<br>20<br>quasi-bidirectional I/O 7|||
|INT|13<br>1<br>interrupt output (active LOW)|||
|SCL|14<br>2<br>serial clock line|||
|SDA|15<br>4<br>serial data line|||
|VDD|16<br>5<br>supply voltage|||
|n.c.|-<br>3, 8, 13, 18<br>not connected|||
## **7. Functional description**
“ ” Refer to Figure 1 Block diagram .
## **7.1 Device address**
Following a START condition, the bus master must send the address of the slave it is accessing and the operation it wants to perform (read or write). The address format of the PCA8574/74A is shown in Figure 6. Slave address pins A2, A1 and A0 are held HIGH or LOW to choose one of eight slave addresses. To conserve power, no internal pull-up resistors are incorporated on pins A2, A1, or A0 so they must be externally held HIGH or LOW. The address pins (A2, A1, A0) can connect to VDD or VSS directly or through resistors.
**==> picture [359 x 107] intentionally omitted <==**
**----- Start of picture text -----**<br>
R/W R/W<br>slave address slave address<br>0 1 0 0 A2 A1 A0 0 0 1 1 1 A2 A1 A0 0<br>fixed hardware fixed hardware<br>selectable selectable<br>002aah469 002aah470<br>a. PCA8574 b. PCA8574A<br>Fig 6. PCA8574 and PCA8574A slave addresses<br>**----- End of picture text -----**<br>
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A **Product data sheet**
**Rev. 3 — 3 June 2013**
**5 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
The last bit of the first byte defines the operation to be performed. When set to logic 1 a read is selected, while a logic 0 selects a write operation (write operation is shown in Figure 6).
## **7.1.1 Address maps**
The PCA8574 and PCA8574A are functionally the same, but have a different fixed portion (A6 to A3) of the slave address. This allows eight of the PCA8574 and eight of the PCA8574A to be on the same I[2] C-bus without address conflict.
## **Table 4. PCA8574 address map**
|**Pin connectivity**|**Pin connectivity**|**Pin connectivity**|**Address of PCA8574**|**Address of PCA8574**|**Address of PCA8574**|**Address of PCA8574**|**Address of PCA8574**|**Address of PCA8574**|**Address of PCA8574**|**Address of PCA8574**|**Address byte value**|**Address byte value**|**7-bit**<br>**hexadecimal**<br>**address**<br>**without R/W**|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|**A2**|**A1**|**A0**|**A6**|**A5**|**A4**|**A3**|**A2**|**A1**|**A0**|**R/W**|**Write**|**Read**||
|VSS<br>VSS<br>VSS|||0<br>1<br>0<br>0<br>0<br>0<br>0<br>-||||||||40h<br>41h||20h|
|VSS<br>VSS<br>VDD|||0<br>1<br>0<br>0<br>0<br>0<br>1<br>-||||||||42h<br>43h||21h|
|VSS<br>VDD<br>VSS|||0<br>1<br>0<br>0<br>0<br>1<br>0<br>-||||||||44h<br>45h||22h|
|VSS<br>VDD<br>VDD|||0<br>1<br>0<br>0<br>0<br>1<br>1<br>-||||||||46h<br>47h||23h|
|VDD<br>VSS<br>VSS|||0<br>1<br>0<br>0<br>1<br>0<br>0<br>-||||||||48h<br>49h||24h|
|VDD<br>VSS<br>VDD|||0<br>1<br>0<br>0<br>1<br>0<br>1<br>-||||||||4Ah<br>4Bh||25h|
|VDD<br>VDD<br>VSS|||0<br>1<br>0<br>0<br>1<br>1<br>0<br>-||||||||4Ch<br>4Dh||26h|
|VDD<br>VDD<br>VDD|||0<br>1<br>0<br>0<br>1<br>1<br>1<br>-||||||||4Eh<br>4Fh||27h|
**Table 5. PCA8574A address map**
|**Pin connectivity**|**Pin connectivity**|**Pin connectivity**|**Address of PCA8574A**|**Address of PCA8574A**|**Address of PCA8574A**|**Address of PCA8574A**|**Address of PCA8574A**|**Address of PCA8574A**|**Address of PCA8574A**|**Address of PCA8574A**|**Address byte value**|**Address byte value**|**7-bit**<br>**hexadecimal**<br>**address**<br>**without R/W**|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|**A2**|**A1**|**A0**|**A6**|**A5**|**A4**|**A3**|**A2**|**A1**|**A0**|**R/W**|**Write**|**Read**||
|VSS<br>VSS<br>VSS|||0<br>1<br>1<br>1<br>0<br>0<br>0<br>-||||||||70h<br>71h||38h|
|VSS<br>VSS<br>VDD|||0<br>1<br>1<br>1<br>0<br>0<br>1<br>-||||||||72h<br>73h||39h|
|VSS<br>VDD<br>VSS|||0<br>1<br>1<br>1<br>0<br>1<br>0<br>-||||||||74h<br>75h||3Ah|
|VSS<br>VDD<br>VDD|||0<br>1<br>1<br>1<br>0<br>1<br>1<br>-||||||||76h<br>77h||3Bh|
|VDD<br>VSS<br>VSS|||0<br>1<br>1<br>1<br>1<br>0<br>0<br>-||||||||78h<br>79h||3Ch|
|VDD<br>VSS<br>VDD|||0<br>1<br>1<br>1<br>1<br>0<br>1<br>-||||||||7Ah<br>7Bh||3Dh|
|VDD<br>VDD<br>VSS|||0<br>1<br>1<br>1<br>1<br>1<br>0<br>-||||||||7Ch<br>7Dh||3Eh|
|VDD<br>VDD<br>VDD|||0<br>1<br>1<br>1<br>1<br>1<br>1<br>-||||||||7Eh<br>7Fh||3Fh|
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A **Product data sheet**
All information provided in this document is subject to legal disclaimers. **Rev. 3 — 3 June 2013**
**6 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **8. I/O programming**
## **8.1 Quasi-bidirectional I/Os**
A quasi-bidirectional I/O is an input or output port without using a direction control register. Whenever the master reads the register, the value returned to master depends on the actual voltage or status of the pin. At power-on, all the ports are HIGH with a weak 100 A internal pull-up to VDD, but can be driven LOW by an internal transistor, or an external signal. The I/O ports are entirely independent of each other, but each I/O octal is controlled by the same read or write data byte.
Advantages of the quasi-bidirectional I/O over totem pole I/O include:
- Better for driving LEDs since the p-channel (transistor to VDD) is small, which saves die size and therefore cost. LED drive only requires an internal transistor to ground, while the LED is connected to VDD through a current-limiting resistor. Totem pole I/O have both n-channel and p-channel transistors, which allow solid HIGH and LOW output levels without a pull-up resistor — good for logic levels.
- Simpler architecture — only a single register and the I/O can be both input and output at the same time. Totem pole I/O have a direction register that specifies the port pin direction and it is always in that configuration unless the direction is explicitly changed.
- Does not require a command byte. The simplicity of one register (no need for the pointer register or, technically, the command byte) is an advantage in some embedded systems where every byte counts because of memory or bandwidth limitations.
There is only one register to control four possibilities of the port pin: Input HIGH, input LOW, output HIGH, or output LOW.
**Input HIGH:** The master needs to write 1 to the register to set the port as an input mode if the device is not in the default power-on condition. The master reads the register to check the input status. If the external source pulls the port pin up to VDD or drives logic 1, then the master will read the value of 1.
**Input LOW:** The master needs to write 1 to the register to set the port to input mode if the device is not in the default power-on condition. The master reads the register to check the input status. If the external source pulls the port pin down to VSS or drives logic 0, which sinks the weak 100 A current source, then the master will read the value of 0.
**Output HIGH:** The master writes 1 to the register. There is an additional ‘accelerator’ or strong pull-up current when the master sets the port HIGH. The additional strong pull-up is only active during the HIGH time of the acknowledge clock cycle. This accelerator current helps the port’s 100 A current source make a faster rising edge into a heavily loaded output, but only at the start of the acknowledge clock cycle to avoid bus contention if an external signal is pulling the port LOW to VSS/driving the port with logic 0 at the same time. After the half clock cycle there is only the 100 A current source to hold the port HIGH.
**Output LOW:** The master writes 0 to the register. There is a strong current sink transistor that holds the port pin LOW. A large current may flow into the port, which could potentially damage the part if the master writes a 0 to the register and an external source is pulling the port HIGH at the same time.
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A **Product data sheet**
**Rev. 3 — 3 June 2013**
**7 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
**==> picture [308 x 169] intentionally omitted <==**
**----- Start of picture text -----**<br>
VDD<br>input HIGH<br>weak 100 µA<br>pull-up with current source output HIGH<br>resistor to VDD or (inactive when output LOW)<br>external drive HIGH<br>accelerator<br>pull-up<br>P port<br>P7 - P0<br>pull-down with<br>resistor to VSS or output LOW<br>external drive LOW<br>input LOW<br>VSS<br>002aah683<br>Fig 7. Simple quasi-bidirectional I/O<br>**----- End of picture text -----**<br>
## **8.2 Writing to the port (Output mode)**
The master (microcontroller) sends the START condition and slave address setting the last bit of the address byte to logic 0 for the write mode. The PCA8574/74A acknowledges and the master then sends the data byte for P7 to P0 to the port register. As the clock line goes HIGH, the 8-bit data is presented on the port lines after it has been acknowledged by the PCA8574/74A. If a LOW is written, the strong pull-down turns on and stays on. If a HIGH is written, the strong pull-up turns on for[1] ⁄2 of the clock cycle, then the line is held HIGH by the weak current source. The master can then send a STOP or ReSTART condition or continue sending data. The number of data bytes that can be sent successively is not limited and the previous data is overwritten every time a data byte has been sent and acknowledged.
Ensure a logic 1 is written for any port that is being used as an input to ensure the strong external pull-down is turned off.
**==> picture [441 x 191] intentionally omitted <==**
**----- Start of picture text -----**<br>
SCL 1 2 3 4 5 6 7 8 9<br>slave address data 1 data 2<br>SDA S A6 A5 A4 A3 A2 A1 A0 0 A P7 P6 1 P4 P3 P2 P1 P0 A P7 P6 0 P4 P3 P2 P1 P0 A<br>START condition R/W P5 P5 acknowledge<br>acknowledge acknowledge from slave<br>from slave from slave<br>write to port<br>tv(Q) tv(Q)<br>data output from port DATA 1 VALID DATA 2 VALID<br>P5 output voltage<br>P5 pull-up output current Itrt(pu)<br>IOH<br>INT<br>trst(INT) 002aah623<br>**----- End of picture text -----**<br>
**Fig 8. Write mode (output)**
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A
All information provided in this document is subject to legal disclaimers.
**Product data sheet**
**Rev. 3 — 3 June 2013**
**8 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
Simple code WRITE mode:
<S> <slave address + write> < **ACK** > <data out> < **ACK** > <data out> < **ACK** > ... <data out> < **ACK** > <P>
**Remark:** Bold type = generated by slave device.
## **8.3 Reading from a port (Input mode)**
The port must have been previously written to logic 1, which is the condition after power-on reset. To enter the Read mode the master (microcontroller) addresses the slave device and sets the last bit of the address byte to logic 1 (address byte read). The slave will acknowledge and then send the data byte to the master. The master will NACK and then send the STOP condition or ACK and read the input register again.
The read of any pin being used as an output will indicate HIGH or LOW depending on the actual state of the input pin.
If the data on the input port changes faster than the master can read, this data may be lost. The DATA 2 and DATA 3 are lost because these data did not meet the setup time and hold time (see Figure 9).
**==> picture [459 x 158] intentionally omitted <==**
**----- Start of picture text -----**<br>
no acknowledge<br>from master<br>slave address data from port data from port<br>SDA S A6 A5 A4 A3 A2 A1 A0 1 A DATA 1 A DATA 4 1 P<br>START condition R/W acknowledge acknowledge STOP<br>from slave from master condition<br>read from<br>port<br>DATA 2<br>data at<br>DATA 1 DATA 3 DATA 4<br>port<br>th(D) tsu(D)<br>INT<br>tv(INT) trst(INT) trst(INT)<br>002aah383<br>**----- End of picture text -----**<br>
A LOW-to-HIGH transition of SDA while SCL is HIGH is defined as the STOP condition (P). Transfer of data can be stopped at any moment by a STOP condition. When this occurs, data present at the last acknowledge phase is valid (output mode). Input data is lost.
## **Fig 9. Read mode (input)**
Simple code for Read mode:
<S> <slave address + read> < **ACK** > < **data in** > <ACK> ... < **data in** > <ACK> < **data in** > <NACK> <P>
**Remark:** Bold type = generated by slave device.
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A
All information provided in this document is subject to legal disclaimers. **Rev. 3 — 3 June 2013**
**Product data sheet**
**9 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **8.4 Power-on reset**
When power is applied to VDD, an internal Power-On Reset (POR) holds the PCA8574; PCA8574A in a reset condition until VDD has reached VPOR. At that point, the reset condition is released and the PCA8574; PCA8574A registers and I[2] C-bus/SMBus state machine will initialize to their default states of all I/Os to inputs with weak current source to VDD. Thereafter VDD must be lowered below VPOR and back up to the operation voltage for power-on reset cycle.
## **8.5 Interrupt output (INT)**
The PCA8574/74A provides an open-drain output (INT) which can be fed to a corresponding input of the microcontroller (see Figure 10). As soon as a port input is changed, the INT will be active (LOW) and notify the microcontroller.
An interrupt is generated at any rising or falling edge of the port inputs. After time tv(Q), the signal INT is valid.
The interrupt will reset to HIGH when data on the port is changed to the original setting or data is read or written by the master.
In the Write mode, the interrupt may be reset (HIGH) on the rising edge of the acknowledge bit of the data byte and also on the rising edge of the write to port pulse. The interrupt will always be reset (HIGH) on the falling edge of the write to port pulse (see Figure 8).
The interrupt is reset (HIGH) in the Read mode on the rising edge of the acknowledge of slave address byte and on the rising edge of the read from port pulse (see Figure 9).
During the interrupt reset, any I/O change close to the read or write pulse may not generate an interrupt, or the interrupt will have a very short pulse. After the interrupt is reset, any change in I/Os will be detected and transmitted as an INT.
At power-on reset all ports are in Input mode and the initial state of the ports is HIGH, therefore, for any port pin that is pulled LOW or driven LOW by external source, the interrupt output will be active (output LOW).
**==> picture [345 x 77] intentionally omitted <==**
**----- Start of picture text -----**<br>
VDD device 1 device 2 device 16<br>PCA8574 PCA8574 PCA8574A<br>MICROCONTROLLER<br>INT INT INT<br>INT<br>002aac682<br>**----- End of picture text -----**<br>
**Fig 10. Application of multiple PCA8574/74As with interrupt**
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A **Product data sheet**
All information provided in this document is subject to legal disclaimers.
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**10 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **9. Characteristics of the I[2] C-bus**
The I[2] C-bus is for 2-way, 2-wire communication between different ICs or modules. The two wires are a serial data line (SDA) and a serial clock line (SCL). Both lines must be connected to a positive supply via a pull-up resistor when connected to the output stages of a device. Data transfer may be initiated only when the bus is not busy.
## **9.1 Bit transfer**
One data bit is transferred during each clock pulse. The data on the SDA line must remain stable during the HIGH period of the clock pulse as changes in the data line at this time will be interpreted as control signals (see Figure 11).
**==> picture [241 x 87] intentionally omitted <==**
**----- Start of picture text -----**<br>
SDA<br>SCL<br>data line change<br>stable; of data<br>data valid allowed mba607<br>**----- End of picture text -----**<br>
**Fig 11. Bit transfer**
## **9.1.1 START and STOP conditions**
Both data and clock lines remain HIGH when the bus is not busy. A HIGH-to-LOW transition of the data line while the clock is HIGH is defined as the START condition (S). A LOW-to-HIGH transition of the data line while the clock is HIGH is defined as the STOP condition (P) (see Figure 12).
**==> picture [351 x 97] intentionally omitted <==**
**----- Start of picture text -----**<br>
SDA<br>SCL<br>S P<br>START condition STOP condition<br>mba608<br>Fig 12. Definition of START and STOP conditions<br>**----- End of picture text -----**<br>
## **9.2 System configuration**
A device generating a message is a ‘transmitter’; a device receiving is the ‘receiver’. The device that controls the message is the ‘master’ and the devices which are controlled by the master are the ‘slaves’ (see Figure 13).
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PCA8574_PCA8574A **Product data sheet**
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**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
**==> picture [432 x 110] intentionally omitted <==**
**----- Start of picture text -----**<br>
SDA<br>SCL<br>MASTER SLAVE SLAVE MASTER MASTER I [2] C-BUS<br>TRANSMITTER/ RECEIVER TRANSMITTER/ TRANSMITTER TRANSMITTER/ MULTIPLEXER<br>RECEIVER RECEIVER RECEIVER<br>SLAVE<br>002aaa966<br>**----- End of picture text -----**<br>
**Fig 13. System configuration**
## **9.3 Acknowledge**
The number of data bytes transferred between the START and the STOP conditions from transmitter to receiver is not limited. Each byte of eight bits is followed by one acknowledge bit (see Figure 14). The acknowledge bit is an active LOW level (generated by the receiving device) that indicates to the transmitter that the data transfer was successful.
A slave receiver which is addressed must generate an acknowledge after the reception of each byte. Also a master must generate an acknowledge after the reception of each byte that has been clocked out of the slave transmitter. The device that wants to issue an acknowledge bit has to pull down the SDA line during the acknowledge clock pulse, so that the SDA line is stable LOW during the HIGH period of the acknowledge bit related clock pulse; set-up and hold times must be taken into account.
A master receiver must signal an end of data to the transmitter by **not** generating an acknowledge on the last byte that has been clocked out of the slave. In this event, the transmitter must leave the data line HIGH to enable the master to generate a STOP condition.
**==> picture [297 x 130] intentionally omitted <==**
**----- Start of picture text -----**<br>
data output<br>by transmitter<br>not acknowledge<br>data output<br>by receiver<br>acknowledge<br>SCL from master<br>1 2 8 9<br>S<br>clock pulse for<br>START acknowledgement<br>condition 002aaa987<br>**----- End of picture text -----**<br>
**Fig 14. Acknowledgement on the I[2] C-bus**
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PCA8574_PCA8574A
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**Product data sheet**
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**PCA8574 PCA8574A ;**
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**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **10. Application design-in information**
## **10.1 Bidirectional I/O expander applications**
In the 8-bit I/O expander application shown in Figure 15, P0 and P1 are inputs, and P2 to P7 are outputs. When used in this configuration, during a write, **the input (P0 and P1) must be written as HIGH so the external devices fully control the input ports** . The desired HIGH or LOW logic levels may be written to the ports used as outputs (P2 to P7). If 10 A internal output HIGH is not enough current source, the port needs external pull-up resistor. During a read, the logic levels of the external devices driving the input ports (P0 and P1) and the previous written logic level to the output ports (P2 to P7) will be read.
The GPIO also has an interrupt line (INT) that can be connected to the interrupt logic of the microcontroller. By sending an interrupt signal on this line, the remote I/O informs the microprocessor that there has been a change of data on its ports without having to communicate via the I[2] C-bus.
**==> picture [328 x 152] intentionally omitted <==**
**----- Start of picture text -----**<br>
VDD<br>VDD<br>VDD<br>SDA P0 temperature sensor<br>CORE SCL P1 battery status<br>PROCESSOR INT P2 control for latch<br>P3 control for switch<br>P4 control for audio<br>A0 P5 control for camera<br>A1 P6 control for MP3<br>A2 P7<br>002aah625<br>Fig 15. Bidirectional I/O expander application<br>**----- End of picture text -----**<br>
## **10.2 How to read and write to I/O expander (example)**
In the application example of PCA8574 shown in Figure 15, the microcontroller wants to control the P3 switch ON and the P7 LED ON when the temperature sensor P0 changes.
1. When the system power on:
Core Processor needs to issue an initial command to set P0 and P1 as inputs and P[7:2] as outputs with value 1010 00 (LED off, MP3 off, camera on, audio off, switch off and latch off).
2. Operation:
When the temperature changes above the threshold, the temperature sensor signal will toggle from HIGH to LOW. The INT will be activated and notifies the ‘core processor’ that there have been changes on the input pins. Read the input register. If P0 = 0 (temperature sensor has changed), then turn on LED and turn on switch.
3. Software code:
```
//System Power on
```
```
// write to PCA8574 with data 1010 0011b to set P[7:2] outputs and P[1:0] inputs
<S> <0100 0000> <ACK> <1010 0011> <ACK> <P>//Initial setting for PCA8574
```
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PCA8574_PCA8574A **Product data sheet**
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**13 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
```
while (INT == 1); //Monitor the interrupt pin. If INT = 1 do nothing
//When INT = 0 then read input ports
```
```
<S> <slave address read> <ACK> <1010 0010> <NACK> <P> //Read PCA8574 data
If (P0 == 0) //Temperature sensor activated
{
```
```
// write to PCA8574 with data 0010 1011b to turn on LED (P7), on Switch (P3)
and keep P[1:0] as input ports.
```
```
<S> <0100 0000> <ACK> <0010 1011> <ACK> <P> // Write to PCA8574
```
```
}
```
## **10.3 High current-drive load applications**
The GPIO has a minimum guaranteed sinking current of 25 mA per bit at 4.5 V. In applications requiring additional drive, two port pins may be connected together to sink up to 50 mA current. Both bits must then always be turned on or off together. Up to 8 pins can be connected together to drive 200 mA, which is the device recommended total limit. Each pin needs its own limiting resistor as shown in Figure 16 to prevent damage to the device should all ports not be turned on at the same time.
**==> picture [307 x 145] intentionally omitted <==**
**----- Start of picture text -----**<br>
VDD<br>VDD VDD<br>SDA P0<br>CORE SCL P1<br>PROCESSOR INT P2<br>P3 LOAD<br>P4<br>A0 P5<br>A1 P6<br>A2 P7<br>002aah472<br>Fig 16. High current-drive load application<br>**----- End of picture text -----**<br>
## **10.4 Migration path**
NXP offers newer, more capable drop-in replacements for the PCF8574/74A in newer space-saving packages.
**Table 6. Migration path**
|**Type number**|**I2C-bus**|**Voltage range**|**Number of**|**Interrupt**|**Reset**|**Total package**|
|---|---|---|---|---|---|---|
||**frequency**||**addresses**|||**sink current**|
||||**per device**||||
|PCF8574/74A|100 kHz|2.5 V to 6 V|8|yes|no|80 mA|
|PCA8574/74A|400 kHz|2.3 V to 5.5 V|8|yes|no|200 mA|
|PCA9674/74A|1 MHz Fm+|2.3 V to 5.5 V|64|yes|no|200 mA|
|PCA9670|1 MHz Fm+|2.3 V to 5.5 V|64|no|yes|200 mA|
|PCA9672|1 MHz Fm+|2.3 V to 5.5 V|16|yes|yes|200 mA|
PCA9670 replaces the interrupt output of the PCA9674 with a hardware reset input to retain the maximum number of addresses. The PCA9672 replaces address A2 of the PCA9674 with a hardware reset input to retain the interrupt, but limit the number of addresses.
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**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **11. Limiting values**
**Table 7. Limiting values**
_In accordance with the Absolute Maximum Rating System (IEC 60134)._
|**Symbol**|**Parameter**|**Conditions**||**Min**|**Max**|**Unit**|
|---|---|---|---|---|---|---|
|VDD|supply voltage|||0.5|+6|V|
|IDD|supply current|||-|100|mA|
|ISS|ground supply current|||-|400|mA|
|VI|input voltage|||VSS0.5|5.5|V|
|II|input current|||-|20|mA|
|IO|output current||[1]|-|50|mA|
|Ptot|total power dissipation|||-|400|mW|
|P/out|power dissipation per output|||-|100|mW|
|Tj(max)|maximum junction temperature|||-|125|C|
|Tstg|storage temperature|||65|+150|C|
|Tamb|ambient temperature|operating||40|+85|C|
[1] Total package (maximum) output current is 400 mA.
## **12. Thermal characteristics**
**Table 8. Thermal characteristics**
|**Symbol**<br>**Parameter**|**Conditions**<br>**Typ**<br>**Unit**|
|---|---|
|Rth(j-a)<br>thermal resistance from junction<br>to ambient|SO16 package<br>115<br>C/W|
||TSSOP16 package<br>160<br>C/W|
||SSOP20 package<br>136<br>C/W|
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PCA8574_PCA8574A **Product data sheet**
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**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **13. Static characteristics**
**Table 9. Static characteristics** _VDD = 2.3 V to 5.5 V; VSS = 0 V; Tamb =_ _40_ _C to +85_ _C; unless otherwise specified._
|**Symbol**<br>**Parameter**|**Conditions**<br>**Min**<br>**Typ**<br>**Max**<br>**Unit**|
|---|---|
|**Supplies**||
|VDD<br>supply voltage|2.3<br>-<br>5.5<br>V|
|IDD<br>supply current|Operating mode; no load;<br>VI= VDDor VSS; fSCL= 400 kHz;<br>A0, A1, A2 = static H or L<br>-<br>200<br>500<br>A|
|Istb<br>standby current|Standby mode; no load;<br>VI= VDDor VSS; fSCL= 0 kHz<br>-<br>4.5<br>10<br>A|
|VPOR<br>power-on reset voltage|[1]<br>-<br>1.8<br>2.0<br>V|
|**Input SCL; input/output SDA**||
|VIL<br>LOW-level input voltage|0.5<br>-<br>+0.3VDD<br>V|
|VIH<br>HIGH-level input voltage|0.7VDD<br>-<br>5.5<br>V|
|IOL<br>LOW-level output current|VOL= 0.4 V; VDD= 2.3 V<br>20<br>35<br>-<br>mA|
||VOL= 0.4 V; VDD= 3.0 V<br>25<br>44<br>-<br>mA|
||VOL= 0.4 V; VDD= 4.5 V<br>30<br>57<br>-<br>mA|
|IL<br>leakage current|VI= VDDor VSS<br>1<br>-<br>+1<br>A|
|Ci<br>input capacitance|VI= VSS<br>-<br>5<br>10<br>pF|
|**I/Os; P0 to P7**||
|VIL<br>LOW-level input voltage|0.5<br>-<br>+0.3VDD<br>V|
|VIH<br>HIGH-level input voltage|0.7VDD<br>-<br>5.5<br>V|
|IOL<br>LOW-level output current|VOL= 0.5 V; VDD= 2.3 V<br>[2]<br>12<br>26<br>-<br>mA|
||VOL= 0.5 V; VDD= 3.0 V<br>[2]<br>17<br>33<br>-<br>mA|
||VOL= 0.5 V; VDD= 4.5 V<br>[2]<br>25<br>40<br>-<br>mA|
|IOL(tot)<br>total LOW-level output current|VOL= 0.5 V; VDD= 4.5 V<br>[2]<br>-<br>-<br>200<br>mA|
|IOH<br>HIGH-level output current|VOH= VSS<br>30<br>138<br>300<br>A|
|Itrt(pu)<br>transient boosted pull-up current|VOH= VSS; see Figure 8<br>0.5<br>1.0<br>-<br>mA|
|Ci<br>input capacitance|[3]<br>-<br>2.1<br>10<br>pF|
|Co<br>output capacitance|[3]<br>-<br>2.1<br>10<br>pF|
|**Interrupt INT**<br>**(see Figure 8**<br> **and Figure 9**<br>**)**||
|IOL<br>LOW-level output current|VOL= 0.4 V<br>3.0<br>-<br>-<br>mA|
|Co<br>output capacitance|-<br>3<br>5<br>pF|
|**Inputs A0, A1, A2**||
|VIL<br>LOW-level input voltage|0.5<br>-<br>+0.3VDD<br>V|
|VIH<br>HIGH-level input voltage|0.7VDD<br>-<br>5.5<br>V|
|ILI<br>input leakage current|1<br>-<br>+1<br>A|
|Ci<br>input capacitance|-<br>3.5<br>5<br>pF|
[1] The power-on reset circuit resets the I[2] C-bus logic with VDD < VPOR and sets all I/Os to logic 1 (with current source to VDD).
[2] Each bit must be limited to a maximum of 25 mA and the total package limited to 200 mA due to internal busing limits.
[3] The value is not tested, but verified on sampling basis.
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A
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**Product data sheet**
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**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **14. Dynamic characteristics**
|**Table 10.**|**Dynamic characteristics**||||||||
|---|---|---|---|---|---|---|---|---|
|_VDD = 2.3 V to 5.5 V; VSS = 0 V; Tamb =__40__C to +85__C;_|||_unless otherwise specified. Limits are for Fast-mode I2C-bus._||||||
|**Symbol**|**Parameter**||**Conditions**||**Min**|**Typ**|**Max**|**Unit**|
|fSCL|SCL clock frequency||||0|-|400|kHz|
|tBUF|bus free time between a STOP and START||||1.3|-|-|s|
||condition||||||||
|tHD;STA|hold time (repeated) START condition||||0.6|-|-|s|
|tSU;STA|set-up time for a repeated START|condition|||0.6|-|-|s|
|tSU;STO|set-up time for STOP condition||||0.6|-|-|s|
|tHD;DAT|data hold time||||0|-|-|ns|
|tVD;ACK|data valid acknowledge time|||[1]|0.1|-|0.9|s|
|tVD;DAT|data valid time|||[2]|50|-|-|ns|
|tSU;DAT|data set-up time||||100|-|-|ns|
|tLOW|LOW period of the SCL clock||||1.3|-|-|s|
|tHIGH|HIGH period of the SCL clock||||0.6|-|-|s|
|tf|fall time of both SDA and SCL signals||[3]<br>[4]||20 + 0.1Cb[5]|-|300|ns|
|tr|rise time of both SDA and SCL signals||||20 + 0.1Cb[5]|-|300|ns|
|tSP|pulse width of spikes that must be|||[6]|-|-|50|ns|
||suppressed by the input filter||||||||
|**Port timing; CL** **100 pF (see Figure 8**<br> **and **||**Figure 9**<br>**)**|||||||
||||||||||
|tv(Q)|data output valid time||||-|-|4|s|
|tsu(D)|data input set-up time||||0|-|-|s|
|th(D)|data input hold time||||4|-|-|s|
|**Interrupt timing; CL** **100 pF (seeFigure 8**<br>||**andFigure**|**9**<br>**)**||||||
||||||||||
|tv(INT)|valid time on pin INT||from port to INT||-|-|4|s|
|trst(INT)|reset time on pin INT||from SCL to INT||-|-|4|s|
[1] tVD;ACK = time for Acknowledgement signal from SCL LOW to SDA (out) LOW.
[2] tVD;DAT = minimum time for SDA data out to be valid following SCL LOW.
[3] A master device must internally provide a hold time of at least 300 ns for the SDA signal (refer to the VIL of the SCL signal) in order to bridge the undefined region SCL’s falling edge.
[4] The maximum tf for the SDA and SCL bus lines is specified at 300 ns. The maximum fall time for the SDA output stage tf is specified at 250 ns. This allows series protection resistors to be connected between the SDA and the SCL pins and the SDA/SCL bus lines without exceeding the maximum specified tf.
[5] Cb = total capacitance of one bus line in pF.
- [6] Input filters on the SDA and SCL inputs suppress noise spikes less than 50 ns.
© NXP B.V. 2013. All rights reserved.
PCA8574_PCA8574A **Product data sheet**
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**17 of 32**
**PCA8574 PCA8574A ;**
**NXP Semiconductors**
**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
**==> picture [383 x 191] intentionally omitted <==**
**----- Start of picture text -----**<br>
START bit 7 STOP<br>protocol condition MSB bit 6 bit 0 acknowledge condition<br>(A6) (R/W) (A)<br>(S) (A7) (P)<br>tSU;STA tLOW tHIGH<br>1 / fSCL<br>SCL 0.7 × VDD<br>0.3 × VDD<br>tBUF tf<br>tr<br>SDA 0.7 × VDD<br>0.3 × VDD<br>tHD;STA tSU;DAT tHD;DAT tVD;DAT tVD;ACK tSU;STO<br>002aab175<br>Rise and fall times refer to VIL and VIH.<br>Fig 17. I [2] C-bus timing diagram<br>**----- End of picture text -----**<br>
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PCA8574_PCA8574A **Product data sheet**
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**PCA8574 PCA8574A ;**
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**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **15. Package outline**
## **SO16: plastic small outline package; 16 leads; body width 7.5 mm**
## **SOT162-1**
**==> picture [478 x 570] intentionally omitted <==**
**----- Start of picture text -----**<br>
D E A<br>X<br>c<br>y HE v M A<br>Z<br>16 9<br>Q<br>A2 A<br>A1 (A )3<br>pin 1 index<br>θ<br>L p<br>L<br>1 8 detail X<br>e w M<br>b p<br>0 5 10 mm<br>scale<br>DIMENSIONS (inch dimensions are derived from the original mm dimensions)<br>UNIT max.A A1 A2 A3 bp c D [(1)] E [(1)] e HE L Lp Q v w y Z (1) θ<br>0.3 2.45 0.49 0.32 10.5 7.6 10.65 1.1 1.1 0.9<br>mm 2.65 0.1 2.25 0.25 0.36 0.23 10.1 7.4 1.27 10.00 1.4 0.4 1.0 0.25 0.25 0.1 0.4 8o<br>0.012 0.096 0.019 0.013 0.41 0.30 0.419 0.043 0.043 0.035 0o<br>inches 0.1 0.01 0.05 0.055 0.01 0.01 0.004<br>0.004 0.089 0.014 0.009 0.40 0.29 0.394 0.016 0.039 0.016<br>Note<br>1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included.<br>OUTLINE REFERENCES EUROPEAN<br>ISSUE DATE<br>VERSION IEC JEDEC JEITA PROJECTION<br>99-12-27<br> SOT162-1 075E03 MS-013<br>03-02-19<br>**----- End of picture text -----**<br>
All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
**Rev. 3 — 3 June 2013**
**Fig 18. Package outline SOT162-1 (SO16)** PCA8574_PCA8574A **Product data sheet**
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**Remote 8-bit I/O expander for I[2] C-bus with interrupt**
## **TSSOP16: plastic thin shrink small outline package; 16 leads; body width 4.4 mm**
**==> picture [43 x 8] intentionally omitted <==**
**----- Start of picture text -----**<br>
SOT403-1<br>**----- End of picture text -----**<br>
**==> picture [488 x 603] intentionally omitted <==**
**----- Start of picture text -----**<br>
D E A<br>X<br>c<br>y HE v M A<br>Z<br>16 9<br>Q<br>A2 (A )3 A<br>pin 1 index A1<br>θ<br>L p<br>L<br>1 8<br>detail X<br>w M<br>e b p<br>0 2.5 5 mm<br>scale<br>DIMENSIONS (mm are the original dimensions)<br>UNIT max.A A1 A2 A3 bp c D [(1)] E [(2)] e HE L Lp Q v w y Z (1) θ<br>mm 1.1 0.150.05 0.950.80 0.25 0.300.19 0.20.1 5.14.9 4.54.3 0.65 6.66.2 1 0.750.50 0.40.3 0.2 0.13 0.1 0.400.06 80oo<br>Notes<br>1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.<br>2. Plastic interlead protrusions of 0.25 mm maximum per side are not included.<br>OUTLINE REFERENCES EUROPEAN<br>ISSUE DATE<br>VERSION IEC JEDEC JEITA PROJECTION<br>99-12-27<br> SOT403-1 MO-153<br>03-02-18<br>Package outline SOT403-1 (TSSOP16)<br>_PCA8574APCA8574A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.<br>**----- End of picture text -----**<br>
**Fig 19. Package outline SOT403-1 (TSSOP16)** PCA8574_PCA8574APCA8574A
**Product data sheet**
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## **SSOP20: plastic shrink small outline package; 20 leads; body width 4.4 mm**
**==> picture [43 x 8] intentionally omitted <==**
**----- Start of picture text -----**<br>
SOT266-1<br>**----- End of picture text -----**<br>
**==> picture [479 x 570] intentionally omitted <==**
**----- Start of picture text -----**<br>
D E A<br>X<br>c<br>y HE v M A<br>Z<br>20 11<br>Q<br>pin 1 index A2 A1 (A )3 A<br>θ<br>L p<br>L<br>1 10<br>detail X<br>w M<br>e b p<br>0 2.5 5 mm<br>scale<br>DIMENSIONS (mm are the original dimensions)<br>UNIT max.A A1 A2 A3 bp c D [(1)] E [(1)] e HE L Lp Q v w y Z (1) θ<br>mm 1.5 0.150 1.41.2 0.25 0.320.20 0.200.13 6.66.4 4.54.3 0.65 6.66.2 1 0.750.45 0.650.45 0.2 0.13 0.1 0.480.18 100oo<br>Note<br>1. Plastic or metal protrusions of 0.20 mm maximum per side are not included.<br>OUTLINE REFERENCES EUROPEAN<br>ISSUE DATE<br>VERSION IEC JEDEC JEITA PROJECTION<br>99-12-27<br> SOT266-1 MO-152<br>03-02-19<br>**----- End of picture text -----**<br>
**Fig 20. Package outline SOT266-1 (SSOP20)** PCA8574_PCA8574A
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**Product data sheet**
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## **16. Handling information**
All input and output pins are protected against ElectroStatic Discharge (ESD) under normal handling. When handling ensure that the appropriate precautions are taken as described in _JESD625-A_ or equivalent standards.
## **17. Soldering of SMD packages**
This text provides a very brief insight into a complex technology. A more in-depth account of soldering ICs can be found in Application Note _AN10365 “Surface mount reflow soldering description”_ .
## **17.1 Introduction to soldering**
Soldering is one of the most common methods through which packages are attached to Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both the mechanical and the electrical connection. There is no single soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high densities that come with increased miniaturization.
## **17.2 Wave and reflow soldering**
Wave soldering is a joining technology in which the joints are made by solder coming from a standing wave of liquid solder. The wave soldering process is suitable for the following:
- Through-hole components
- Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless packages which have solder lands underneath the body, cannot be wave soldered. Also, leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered, due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by component placement and exposure to a temperature profile. Leaded packages, packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
- Board specifications, including the board finish, solder masks and vias
- Package footprints, including solder thieves and orientation
- The moisture sensitivity level of the packages
- Package placement
- Inspection and repair
- Lead-free soldering versus SnPb soldering
## **17.3 Wave soldering**
Key characteristics in wave soldering are:
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- Process issues, such as application of adhesive and flux, clinching of leads, board transport, the solder wave parameters, and the time during which components are exposed to the wave
- Solder bath specifications, including temperature and impurities
## **17.4 Reflow soldering**
Key characteristics in reflow soldering are:
- Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to higher minimum peak temperatures (see Figure 21) than a SnPb process, thus reducing the process window
- Solder paste printing issues including smearing, release, and adjusting the process window for a mix of large and small components on one board
- Reflow temperature profile; this profile includes preheat, reflow (in which the board is heated to the peak temperature) and cooling down. It is imperative that the peak temperature is high enough for the solder to make reliable solder joints (a solder paste characteristic). In addition, the peak temperature must be low enough that the packages and/or boards are not damaged. The peak temperature of the package depends on package thickness and volume and is classified in accordance with Table 11 and 12
## **Table 11. SnPb eutectic process (from J-STD-020D)**
|**Package thickness (mm)**|**Package reflow temperature (****C)**|**Package reflow temperature (****C)**|
|---|---|---|
||**Volume (mm3)**||
||**< 350**|**350**|
|< 2.5|235<br>220||
|2.5|220<br>220||
## **Table 12. Lead-free process (from J-STD-020D)**
|**Package thickness (mm)**|**Package reflow temperature (****C)**|**Package reflow temperature (****C)**|**Package reflow temperature (****C)**|
|---|---|---|---|
||**Volume (mm3)**|||
||**< 350**|**350 to 2000**|**> 2000**|
|< 1.6|260<br>260<br>260|||
|1.6 to 2.5|260<br>250<br>245|||
|> 2.5|250<br>245<br>245|||
Moisture sensitivity precautions, as indicated on the packing, must be respected at all times.
Studies have shown that small packages reach higher temperatures during reflow soldering, see Figure 21.
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PCA8574_PCA8574A **Product data sheet**
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**==> picture [352 x 223] intentionally omitted <==**
**----- Start of picture text -----**<br>
maximum peak temperature<br>= MSL limit, damage level<br>temperature<br>minimum peak temperature<br>= minimum soldering temperature<br>peak<br> temperature<br>time<br>001aac844<br>MSL: Moisture Sensitivity Level<br>Fig 21. Temperature profiles for large and small components<br>**----- End of picture text -----**<br>
For further information on temperature profiles, refer to Application Note _AN10365 “Surface mount reflow soldering description”_ .
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## **18. Soldering: PCB footprints**
**==> picture [481 x 574] intentionally omitted <==**
**----- Start of picture text -----**<br>
Footprint information for reflow soldering of SO16 package SOT162-1<br>Hx<br>Gx<br>P2<br>(0.125) (0.125)<br>Hy Gy By Ay<br>C<br>D2 (4x) P1 D1<br>Generic footprint pattern<br>Refer to the package outline drawing for actual layout<br>solder land<br>occupied area<br>DIMENSIONS in mm<br>P1 P2 Ay By C D1 D2 Gx Gy Hx Hy<br>1.270 1.320 11.200 6.400 2.400 0.700 0.800 10.040 8.600 11.900 11.450<br>sot162-1_fr<br>**----- End of picture text -----**<br>
**Fig 22. PCB footprint for SOT162-1 (SO16); reflow soldering**
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## **Footprint information for reflow soldering of TSSOP16 package**
**==> picture [38 x 7] intentionally omitted <==**
**----- Start of picture text -----**<br>
SOT403-1<br>**----- End of picture text -----**<br>
**==> picture [405 x 470] intentionally omitted <==**
**----- Start of picture text -----**<br>
Hx<br>Gx<br>P2<br>(0.125) (0.125)<br>Hy Gy By Ay<br>C<br>D2 (4x) P1 D1<br>Generic footprint pattern<br>Refer to the package outline drawing for actual layout<br>solder land<br>occupied area<br>DIMENSIONS in mm<br>P1 P2 Ay By C D1 D2 Gx Gy Hx Hy<br>0.650 0.750 7.200 4.500 1.350 0.400 0.600 5.600 5.300 5.800 7.450<br>**----- End of picture text -----**<br>
**==> picture [31 x 6] intentionally omitted <==**
**----- Start of picture text -----**<br>
sot403-1_fr<br>**----- End of picture text -----**<br>
**Fig 23. PCB footprint for SOT403-1 (TSSOP16); reflow soldering**
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**==> picture [481 x 9] intentionally omitted <==**
**----- Start of picture text -----**<br>
Footprint information for reflow soldering of SSOP20 package SOT266-1<br>**----- End of picture text -----**<br>
**==> picture [481 x 564] intentionally omitted <==**
**----- Start of picture text -----**<br>
Hx<br>Gx<br>P2 (0.125)<br>(0.125)<br>Hy Gy By Ay<br>C<br>D2 (4x) P1 D1<br>solder land<br>occupied area<br>DIMENSIONS in mm<br>P1 P2 Ay By C D1 D2 Gx Gy Hx Hy<br>0.650 0.750 7.200 4.500 1.350 0.400 0.600 6.900 5.300 7.300 7.450<br>sot266-1_fr<br>**----- End of picture text -----**<br>
**Fig 24. PCB footprint for SOT266-1 (SSOP20); reflow soldering**
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## **19. Abbreviations**
|**Table 13.**|**Abbreviations**|
|---|---|
|**Acronym**|**Description**|
|CDM|Charged-Device Model|
|CMOS|Complementary Metal Oxide Semiconductor|
|ESD|ElectroStatic Discharge|
|FF|Flip-Flop|
|GPIO|General Purpose Input/Output|
|HBM|Human Body Model|
|I/O|Input/Output|
|I2C-bus|Inter-Integrated Circuit bus|
|IC|Integrated Circuit|
|LED|Light Emitting Diode|
|LP|Low-Pass|
|LSB|Least Significant Bit|
|MSB|Most Significant Bit|
|PLC|Programmable Logic Controller|
|POR|Power-On Reset|
|SMBus|System Management Bus|
## **20. Revision history**
## **Table 14. Revision history**
|**Document ID**|**Release date**<br>**Data sheet status**<br>**Change notice**<br>**Supersedes**|
|---|---|
|PCA8574_PCA8574A v.3|20130603<br>Product data sheet<br>-<br>PCA8574_PCA8574A v.2|
|Modifications:|**•** Section 1“<br>General description<br>”<br> re-written|
||**•** Section 2“<br>Features and benefits<br>”|
||**–**<br>added (new) first bullet item|
||**–**<br>appended “(Fast-mode I2C-bus)” to second bullet item|
||**–**<br>added (new) third bullet item|
||**–**<br>(new) fifth bullet item changed from “50 mA sink capability” to “25 mA sink capability”|
||**–**<br>deleted (old) eighth bullet item, “Readable device ID (manufacturer, device type, and|
||revision)”|
||**–**<br>12th bullet item: deleted phrase “200 V MM per JESD22-A115”|
||**–**<br>14th bullet item: deleted “DIP16”|
||**•** Table 1“<br>Ordering information<br>”<br>:|
||**–**<br>deleted discontinued DIP16 package option (PCA8574N, PCA8574AN)|
||**–**<br>Topside mark for PCA8574ATS corrected from “PCA8574A” to “PA8574A”|
||**–**<br>addedTable note [1]<br>,Table note [2]<br>, Table note [3]<br> and Table note [4]|
||**•** Added (new) Table 2“<br>Ordering options<br>”|
||**•** Figure 1“<br>Block diagram<br>”<br> modified: switched positions of blocks “INTERRUPT LOGIC” and|
||“LP FILTER”|
||**•** Figure 2“<br>Simplified schematic diagram of P0 to P7<br>”<br> modified: removed diode between|
||“VDD” and “P0 to P7” signal lines|
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|**Table 14.**|**Revision history**_…continued_|**Revision history**_…continued_||||
|---|---|---|---|---|---|
|**Document**|**ID**|**Release date**<br>**Data sheet status**<br>**Change notice**|**Supersedes**|||
|Modifications: (continued)||**•** Section 6.1“<br>Pinning<br>”<br>:||||
|||**–**<br>deleted (old) Figure 3, “Pin configuration for DIP16”||||
|||**–**<br>pin names changed from “AD0, AD1, AD2” to “A0, A1, A2”,|respectively|||
|||**•** Section 6.2“<br>Pin description<br>”<br>:(old) Table 3, “Pin description for|SO16, TSSOP16” and (old)|||
|||Table 4, “Pin description for SSOP20” are merged in (new) Table 3“<br>Pin description<br>”||||
|||**•** Section 7.1“<br>Device address<br>”<br> re-written||||
|||**•** Section 7.1.1“<br>Address maps<br>”<br> re-written||||
|||**•** Section 8.1“<br>Quasi-bidirectional I/Os<br>”<br> re-written||||
|||**•** Section 8.2“<br>Writing to the port (Output mode)<br>”<br> re-written||||
|||**•** Figure 8“<br>Write mode (output)<br>”<br>:timing measurement symbol corrected from “td(rst)” to||||
|||“trst(INT)”||||
|||**•** Section 8.3“<br>Reading from a port (Input mode)<br>”<br> re-written||||
|||**•** Figure 9“<br>Read mode (input)<br>”<br>:||||
|||**–**<br>timing measurement symbol corrected from “tv(D)” to “tv(INT)”||||
|||**–**<br>timing measurement symbol corrected from “td(rst)” to “trst(INT)”||||
|||**•** Section 8.4“<br>Power-on reset<br>”<br>:second and third sentences re-written||||
|||**•** Figure 9“<br>Read mode (input)<br>”<br> modified: corrected label from “data into port” to “data at port”||||
|||**•** Section 8.5“<br>Interrupt output (<br>INT<br>)<br>”<br>,fourth, fifth and sixth paragraphs re-written; added new||||
|||seventh paragraph||||
|||**•** Figure 10“<br>Application of multiple PCA8574/74As with interrupt<br>”<br> updated||||
|||(changed from “device 8, PCA8574” to “device 16, PCA8574A”)||||
|||**•** Added (new) Section 10.2“<br>How to read and write to I/O expander (example)<br>”||||
|||**•** Section 10.3“<br>High current-drive load applications<br>”<br>:||||
|||**–**<br>1st sentence changed from “maximum sinking current of 25 mA per bit”||||
|||to “minimum guaranteed sinking current of 25 mA per bit at|4.5 V”|||
|||**–**<br>4th sentence changed from “device total limit” to “device recommended total limit”||||
|||**•** Figure 16“<br>High current-drive load application<br>”<br> modified: added resistor on P6 and P7 signal||||
|||lines||||
|||**•** Added (new) Section 10.4“<br>Migration path<br>”||||
|||**•** Table 7“<br>Limiting values<br>”<br>:added Tj(max)limits||||
|||**•** Added Section 12“<br>Thermal characteristics<br>”||||
|||**•** Table 9“<br>Static characteristics<br>”<br>,sub-section “I/Os; P0 to P7”: added VILand VIH||||
|||characteristics||||
|||**•** Table 10“<br>Dynamic characteristics<br>”<br>,sub-section “Interrupt timing”:||||
|||**–**<br>symbol/parameter corrected from “tv(D), data input valid time”||||
|||to “tv(INT), valid time on pin INT<br>”||||
|||**–**<br>symbol/parameter corrected from “td(rst), reset delay time”||||
|||to “trst(INT), reset time on pin INT<br>”||||
|||**•** Figure 17“<br>I<br>2<br>~~C~~-bus timing diagram<br>”<br> updated: added 0.3VDDand 0.7VDDreference lines||||
|||**•** Deleted (old) Figure 18, “Package outline SOT38-1 (DIP16)”||||
|||**•** Updated soldering information||||
|||**•** Added Section 18“<br>Soldering: PCB footprints<br>”||||
|||||||
|PCA8574_PCA8574A v.2||20070514<br>Product data sheet<br>-|PCA8574_PCA8574A v.1|||
|PCA8574_PCA8574A v.1||20070117<br>Product data sheet<br>-|-|||
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## **21. Legal information**
## **21.1 Data sheet status**
|**Document status[1]**<br>**[2]**|**Product statu**~~**s**~~**[3]**|**Definition**|
|---|---|---|
|Objective [short] data sheet|Development|This document contains data from the objective specification for product development.|
|Preliminary [short] data sheet|Qualification|This document contains data from the preliminary specification.|
|Product [short] data sheet|Production|This document contains the product specification.|
[1] Please consult the most recently issued document before initiating or completing a design.
[2] The term ‘short data sheet’ is explained in section “Definitions”.
[3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status information is available on the Internet at URL http://www.nxp.com.
## **21.2 Definitions**
**Draft —** The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information.
**Short data sheet —** A short data sheet is an extract from a full data sheet with the same product type number(s) and title. A short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. For detailed and full information see the relevant full data sheet, which is available on request via the local NXP Semiconductors sales office. In case of any inconsistency or conflict with the short data sheet, the full data sheet shall prevail.
**Product specification —** The information and data provided in a Product data sheet shall define the specification of the product as agreed between NXP Semiconductors and its customer, unless NXP Semiconductors and customer have explicitly agreed otherwise in writing. In no event however, shall an agreement be valid in which the NXP Semiconductors product is deemed to offer functions and qualities beyond those described in the Product data sheet.
## **21.3 Disclaimers**
**Limited warranty and liability —** Information in this document is believed to be accurate and reliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. NXP Semiconductors takes no responsibility for the content in this document if provided by an information source outside of NXP Semiconductors.
In no event shall NXP Semiconductors be liable for any indirect, incidental, punitive, special or consequential damages (including - without limitation - lost profits, lost savings, business interruption, costs related to the removal or replacement of any products or rework charges) whether or not such damages are based on tort (including negligence), warranty, breach of contract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the _Terms and conditions of commercial sale_ of NXP Semiconductors.
**Right to make changes —** NXP Semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice. This document supersedes and replaces all information supplied prior to the publication hereof.
**Suitability for use —** NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in life support, life-critical or safety-critical systems or equipment, nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors and its suppliers accept no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk.
**Applications —** Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification.
Customers are responsible for the design and operation of their applications and products using NXP Semiconductors products, and NXP Semiconductors accepts no liability for any assistance with applications or customer product design. It is customer’s sole responsibility to determine whether the NXP Semiconductors product is suitable and fit for the customer’s applications and products planned, as well as for the planned application and use of customer’s third party customer(s). Customers should provide appropriate design and operating safeguards to minimize the risks associated with their applications and products.
NXP Semiconductors does not accept any liability related to any default, damage, costs or problem which is based on any weakness or default in the customer’s applications or products, or the application or use by customer’s third party customer(s). Customer is responsible for doing all necessary testing for the customer’s applications and products using NXP Semiconductors products in order to avoid a default of the applications and the products or of the application or use by customer’s third party customer(s). NXP does not accept any liability in this respect.
**Limiting values —** Stress above one or more limiting values (as defined in the Absolute Maximum Ratings System of IEC 60134) will cause permanent damage to the device. Limiting values are stress ratings only and (proper) operation of the device at these or any other conditions above those given in the Recommended operating conditions section (if present) or the Characteristics sections of this document is not warranted. Constant or repeated exposure to limiting values will permanently and irreversibly affect the quality and reliability of the device.
**Terms and conditions of commercial sale —** NXP Semiconductors products are sold subject to the general terms and conditions of commercial sale, as published at http://www.nxp.com/profile/terms, unless otherwise agreed in a valid written individual agreement. In case an individual agreement is concluded only the terms and conditions of the respective agreement shall apply. NXP Semiconductors hereby expressly objects to applying the customer’s general terms and conditions with regard to the purchase of NXP Semiconductors products by customer.
**No offer to sell or license —** Nothing in this document may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights.
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## **NXP Semiconductors**
## **Remote 8-bit I/O expander for I[2] C-bus with interrupt**
**Export control —** This document as well as the item(s) described herein may be subject to export control regulations. Export might require a prior authorization from competent authorities.
**Non-automotive qualified products —** Unless this data sheet expressly states that this specific NXP Semiconductors product is automotive qualified, the product is not suitable for automotive use. It is neither qualified nor tested in accordance with automotive testing or application requirements. NXP Semiconductors accepts no liability for inclusion and/or use of non-automotive qualified products in automotive equipment or applications.
In the event that customer uses the product for design-in and use in automotive applications to automotive specifications and standards, customer (a) shall use the product without NXP Semiconductors’ warranty of the product for such automotive applications, use and specifications, and (b) whenever customer uses the product for automotive applications beyond NXP Semiconductors’ specifications such use shall be solely at customer’s
own risk, and (c) customer fully indemnifies NXP Semiconductors for any liability, damages or failed product claims resulting from customer design and use of the product for automotive applications beyond NXP Semiconductors’ standard warranty and NXP Semiconductors’ product specifications.
**Translations —** A non-English (translated) version of a document is for reference only. The English version shall prevail in case of any discrepancy between the translated and English versions.
## **21.4 Trademarks**
Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners.
**I[2] C-bus —** logo is a trademark of NXP B.V.
## **22. Contact information**
For more information, please visit: **http://www.nxp.com**
For sales office addresses, please send an email to: **salesaddresses@nxp.com**
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## **23. Contents**
|**1**|**General description . . . . . . . . . . . . . . . . . . . . . . 1**|21.1|Data sheet status . . . . . . . . . . . . . . . . . . . . . . 30|
|---|---|---|---|
|**2**|**Features and benefits . . . . . . . . . . . . . . . . . . . . 1**|21.2|Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 30|
|**3**<br>**4**<br>4.1<br>**5**|**Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2**<br>**Ordering information. . . . . . . . . . . . . . . . . . . . . 2**<br>Ordering options . . . . . . . . . . . . . . . . . . . . . . . . 3<br>**Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3**|21.3<br>21.4<br>**22**<br>**23**|Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . 30<br>Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . 31<br>**Contact information . . . . . . . . . . . . . . . . . . . . 31**<br>**Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32**|
|**6**|**Pinning information. . . . . . . . . . . . . . . . . . . . . . 4**|||
|6.1|Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4|||
|6.2|Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 5|||
|**7**|**Functional description . . . . . . . . . . . . . . . . . . . 5**|||
|7.1|Device address. . . . . . . . . . . . . . . . . . . . . . . . . 5|||
|7.1.1|Address maps. . . . . . . . . . . . . . . . . . . . . . . . . . 6|||
|**8**|**I/O programming . . . . . . . . . . . . . . . . . . . . . . . . 7**|||
|8.1|Quasi-bidirectional I/Os . . . . . . . . . . . . . . . . . . 7|||
|8.2|Writing to the port (Output mode) . . . . . . . . . . . 8|||
|8.3|Reading from a port (Input mode) . . . . . . . . . . 9|||
|8.4|Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . 10|||
|8.5|Interrupt output (INT<br>) . . . . . . . . . . . . . . . . . . . 10|||
|**9**|**Characteristics of the I2C-bus . . . . . . . . . . . . 11**|||
|9.1|Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . 11|||
|9.1.1|START and STOP conditions . . . . . . . . . . . . . 11|||
|9.2|System configuration . . . . . . . . . . . . . . . . . . . 11|||
|9.3|Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . 12|||
|**10**|**Application design-in information . . . . . . . . . 13**|||
|10.1|Bidirectional I/O expander applications . . . . . 13|||
|10.2|How to read and write to I/O expander|||
||(example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13|||
|10.3|High current-drive load applications . . . . . . . . 14|||
|10.4|Migration path. . . . . . . . . . . . . . . . . . . . . . . . . 14|||
|**11**|**Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 15**|||
|**12**|**Thermal characteristics . . . . . . . . . . . . . . . . . 15**|||
|**13**|**Static characteristics. . . . . . . . . . . . . . . . . . . . 16**|||
|**14**|**Dynamic characteristics . . . . . . . . . . . . . . . . . 17**|||
|**15**|**Package outline . . . . . . . . . . . . . . . . . . . . . . . . 19**|||
|**16**|**Handling information. . . . . . . . . . . . . . . . . . . . 22**|||
|**17**|**Soldering of SMD packages . . . . . . . . . . . . . . 22**|||
|17.1|Introduction to soldering . . . . . . . . . . . . . . . . . 22|||
|17.2|Wave and reflow soldering . . . . . . . . . . . . . . . 22|||
|17.3|Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 22|||
|17.4|Reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 23|||
|**18**|**Soldering: PCB footprints. . . . . . . . . . . . . . . . 25**|||
|**19**|**Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . 28**|||
|**20**|**Revision history. . . . . . . . . . . . . . . . . . . . . . . . 28**|||
|**21**|**Legal information. . . . . . . . . . . . . . . . . . . . . . . 30**|||
Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’.
**© NXP B.V. 2013.**
**All rights reserved.**
For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com **Date of release: 3 June 2013 Document identifier: PCA8574_PCA8574A**
Updated at February 9, 2023
NXP Semiconductors is a global leader in secure connectivity solutions, driving innovation across the automotive, industrial, IoT, mobile, and communications infrastructure markets. By developing advanced, purpose-built technologies, NXP enables devices to sense, think, connect, and act intelligently, delivering rigorously tested components that make the connected world safer and more efficient. Within the semiconductor space, NXP is highly regarded for its extensive range of high-performance integrated circuits and discrete devices. The brand's portfolio excels in drivers and interfaces, featuring a comprehensive selection of I/O expanders designed to streamline complex system architectures. For demanding high-frequency and wireless applications, NXP provides industry-leading RF FETs and RF/PIN diodes engineered to deliver exceptional signal integrity, efficiency, and reliability. The NXP product lineup further extends to essential discrete components, including versatile bipolar transistors, JFETs, and small signal diodes optimized for precision switching and amplification. Additionally, the portfolio supports advanced automation and smart applications with precision IC sensors, such as MEMS accelerometers, alongside specialized power management solutions like AC/DC LED driver ICs and single MOSFETs for cutting-edge electronics design.
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