AL17150-10BS7-13

**AL17150-10B** Lead-free Green ; **HIGH VOLTAGE STEP-DOWN SWITCHER UP TO 300mA OUTPUT CURRENT** 

## **Description** 

The AL17150-10B is a universal high voltage input step-down regulator product family, which provides accurate Constant Voltage (CV) and outstanding dynamic performance without requiring an optocoupler over line and load regulation. Typical applications are offline low power applications including connected LED lighting power supply for micro-controllers and other IoT applications. 

The AL17150-10B integrates a 500V/1A MOSFET that can make it use fewer external components and create a low Bill Of Material (BOM) cost solution. The AL17150-10B can provide up to 300mA output current and lower than 50mW standby power, which is very suitable for IoT connected lighting devices. 

## **Pin Assignments** 

**(Top View)** 

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NC | 1 | 7 Drain<br>NC | 2 |<br>S 3 6 FB<br>|| |<br>S 4 5 VCC<br>|| ||<br>**----- End of picture text -----**<br>


The AL17150-10B achieves excellent regulation and high power efficiency. The characteristics of max peak current and driving frequency vary as the load change, which can get excellent efficiency performance at light load and improve the overall average efficiency. 

The AL17150-10B has rich protection features to enhance the system safety and reliability. It has Over Temperature Protection, VCC Under Voltage Lock function, Output Short Protection, Over Load Protection and Open Loop Protection. 

## **SO-7** 

## **Applications** 

- IoT Connected Lighting Applications 

- Home Appliance Applications 

- Industrial Controls 

- Standby and Auxiliary 

The AL17150-10B is available in SO-7 package. 

## **Features** 

- Universal 85 to 265 VAC Input Range 

- Internal MOSFET: 500V/1A 

- Tight VFB tolerance ± 4% 

- Maximum 300mA Rated Output Current 

- No Load Power Consumption: < 50mW with External Bias 

- Frequency Modulation to Suppress EMI 

- Under Voltage Lock Out (UVLO) 

- Output Short Protection 

- Over Load Protection; 

- Thermal Shutdown (TSD) 

- Fewer Components 

- Low Audible Noise Solution 

- SO-7 Package 

- **Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)** 

- **Halogen and Antimony Free. “Green” Device (Note 3)** 

- **For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative.** 

- **https://www.diodes.com/quality/product-definitions/** 

Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 

2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free. 

3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. 

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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B** 

## **Typical Applications Circuit** 

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R1<br>FB<br>L1 D4<br>L RF1 D1 VCC C4<br>Drain R2 C5<br>C3 L2 VO+<br>S<br>C1 C2 AL17150-10B<br>C6 R3<br>D3<br>D2<br>N<br>VO-<br>**----- End of picture text -----**<br>


## **Pin Descriptions** 

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Pin Number  Name  Function<br>1, 2  N/C  Not Connected.<br>3, 4  S  Internal Power MOSFET Source. Ground Reference for VCC and FB Pins.<br>Connection Point of External Bypass Capacitor for Internally Generated Control Circuit<br>5  VCC<br>Power Supply.<br>6  FB  Regulator Feedback.<br>7  Drain  Internal Power MOSFET Drain. High-Voltage Current Source Input.<br>Functional Block Diagram<br>|<br>| |<br>5 7<br>VCC Power Drain<br>| |<br>| Driver<br>Logic<br>| |<br>|<br>| |<br>| VREF FB<br>CS Limit<br>| Control |<br>| VLIMIT RCS<br>6<br>A 3, 4 J \<br>FB Protection S<br>**----- End of picture text -----**<br>


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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B** 

## **Absolute Maximum Ratings** (Note 4) 

|**Symbol**<br>~~GO~~<br>~~es~~|**Parameter**<br>~~GO~~|**Rating**<br>~~GO~~|**Unit**<br>~~GO~~|
|---|---|---|---|
|VDSS<br>~~es~~<br>~~es~~|Voltage of Drain to S pin<br>~~eG~~|-0.7 to 500<br>~~eG~~|V<br>~~eG~~|
|VFB<br>~~es~~<br>~~es~~<br>~~es~~|Voltage of FB to S Pin<br>~~eG~~|-0.7 to 6.5<br>~~eG~~|V<br>~~eG~~|
|VCC<br>~~es~~<br>~~es~~<br>~~es~~|Operating VCC Voltage<br>~~eG~~|8.9<br>~~eG~~|V<br>~~eG~~|
|PD<br>~~es~~<br>~~es~~<br>~~es~~|Continuous Power Dissipation (TA= +25°C)<br>~~eG~~|1<br>~~eG~~|W<br>~~eG~~|
|TJ<br>~~es~~<br>~~es~~|Operating Junction Temperature<br>~~eG~~|+150<br>~~eG~~|°C<br>~~eG~~|
|TSTG<br>~~es~~<br>~~a~~<br>~~es~~|Storage Temperature<br>~~eG~~|-65 to +150<br>~~eG~~|°C<br>~~eG~~|
|TLEAD<br>~~es~~|Lead Temperature (Soldering, 10s)|+300|°C|
|θJA<br>~~es~~<br>~~a~~|Thermal Resistance (Junction to Ambient)|139|°C/W|
|θJC<br>~~a~~|Thermal Resistance (Junction to Case)<br>|21<br>|°C/W<br>|
|ESD<br><br>~~eH~~|ESD (Human Body Model)<br>~~a~~<br>~~eH~~|4000<br>~~a~~<br>~~eH~~|V<br>~~a~~|
||ESD (Charge Device Model)<br>~~eH~~|1000<br>~~eH~~|V|



Note: 4. Stresses greater than those listed under _Absolute Maximum Ratings_ can cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under _Recommended Operating Conditions_ is not implied. Exposure to _Absolute Maximum Ratings_ for extended periods can affect device reliability. 

## **Recommended Operating Conditions** 

|**Symbol**|**Parameter**|**Min**|**Max**|**Unit**|
|---|---|---|---|---|
|VCC|Supply Voltage|8.2|8.8|V|
|TA|Ambient Temperature|-40|+125|°C|
|IOUT|Output Current with 3.3V/5V Output Voltage|—|300|mA|



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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B** 

## **Electrical Characteristics** (VCC = 8.8V, TA=+25C, unless otherwise specified.) 

|**Symbol**<br>~~a~~<br>~~SS~~|**Parameter**<br>~~SS~~|**Condition**|**Min**|**Typ**|**Max**|**Unit**|
|---|---|---|---|---|---|---|
|**HV Startup Current Source**<br>~~SS~~|||||||
|IHV<br>~~SS~~<br>~~a~~|HV Supply Current<br>~~SS~~|VCC= 7V; VDRAIN= 100V|1.2|3.5|—|mA|
|ILEAK<br>~~a~~<br>~~SS~~|Leakage Current of Drain<br>~~SS~~|VCC= 8.8V; VDRAIN= 400V|—|10|12|A|
|**VCC Voltage Management**<br>~~SS~~|||||||
|VCC_OFF<br>~~SS~~<br>~~a~~|VCC Supply OFF Threshold Voltage<br>~~SS~~<br>~~a~~|—<br>~~a~~|8.1<br>~~a~~|8.5<br>~~a~~|8.8<br>~~a~~|V<br>~~a~~|
|VCC_ON<br>~~a~~|VCC Supply ON Threshold Voltage<br>~~a~~|—<br>~~a~~|7.8<br>~~a~~|8.2<br>~~a~~|8.6<br>~~a~~|V<br>~~a~~|
|—<br>~~a~~|VCC Supply ON and OFF Hysteresis<br>~~a~~|—<br>~~a~~|—<br>~~a~~|280<br>~~a~~|—<br>~~a~~|mV<br>~~a~~|
|VCC_UVLO<br>~~a~~|Minimum Operating Voltage<br>~~a~~|—<br>~~a~~|—<br>~~a~~|6.5<br>~~a~~|—<br>~~a~~|V<br>~~a~~|
|VCC_RESTART|Restart Voltage|—<br>~~ee~~|—<br>~~es~~|4.5<br>~~ee~~|—<br>~~ee~~|V<br>~~ee~~|
|ICC<br>~~a~~|Operating Current<br>~~a~~<br>~~ae~~|VCC= 7.5V, fS= 40kHz,<br>D = 40%<br>~~a~~<br>~~ae~~<br>~~ee~~|—<br>~~a~~<br>~~ae~~<br>~~es~~|350<br>~~a~~<br>~~ae~~<br>~~ee~~|—<br>~~a~~<br>~~ae~~<br>~~ee~~|A<br>~~a~~<br>~~ae~~<br>~~ee~~|
|ICC_QC<br>~~Se~~|Quiescent Current with No Switching<br>~~Se~~|—<br>~~ee ~~<br>~~Se~~|—<br> ~~es ~~<br>~~Se~~|110<br> ~~ee~~<br>~~Se~~|200<br>~~ee ~~<br>~~Se~~|A<br> ~~ee~~<br>~~Se~~|
|ICC_LATCH<br>~~a~~|Latch Off Current<br>~~a~~|—<br>~~a~~|—<br>~~a~~|26<br>~~a~~|—<br>~~a~~|A<br>~~a~~|
|**Internal MOSFET**<br>~~Se~~|||||||
|VDS<br>~~LL~~|Breakdown Voltage (Note 5)<br>~~LL~~|—<br>~~LL~~|500<br>~~LL~~|—<br>~~LL~~|—<br>~~LL~~|V<br>~~LL~~|
|RDS(ON)<br>~~I~~|ON Resistance<br>~~I~~|—<br>~~I~~|—<br>~~I~~|—<br>~~I~~|12<br>~~I~~|Ω<br>~~I~~|
|**Internal Current Sense**<br>~~SS~~|||||||
|IPK_MAX<br>~~a~~|Peak Current<br>~~a~~|—<br>~~a~~|413<br>~~a~~|500<br>~~a~~|600<br>~~a~~|mA<br>~~a~~|
|tLEB<br>~~I~~|Leading Edge Blanking Time<br>~~I~~|—<br>~~I~~|—<br>~~I~~|250<br>~~I~~|400<br>~~I~~|ns<br>~~I~~|
|ISCP<br>~~nL~~|SCP Point Current<br>~~nL~~|—<br>~~nL~~|—<br>~~nL~~|800<br>~~nL~~|—<br>~~nL~~|mA<br>~~nL~~|
|**Feedback Input (FB Pin)**<br>~~ee~~|||||||
|tMINOFF<br>~~a~~|Minimum off Time<br>~~a~~|—<br>~~a~~|10.5<br>~~a~~|15.5<br>~~a~~|18.5<br>~~a~~|s<br>~~a~~|
|VFB<br>~~a~~|MOSFET Feedback Switch-On Threshold<br>~~a~~|—<br>~~a~~|2.4<br>~~a~~|2.5<br>~~a~~|2.6<br>~~a~~|V<br>~~a~~|
|VFB_OLP<br>~~a~~|OLP Feedback Trigger Threshold<br>~~a~~|—<br>~~a~~|1.56<br>~~a~~|1.7<br>~~a~~|1.84<br>~~a~~|V<br>~~a~~|
|tOLP<br>~~a~~|OLP Delay Time<br>~~a~~|fS= 37kHz<br>~~a~~|—<br>~~a~~|170<br>~~a~~|—<br>~~a~~|ms<br>~~a~~|
|VOLD<br>~~a~~|Open-Loop Detection<br>~~a~~|—<br>~~a~~|—<br>~~a~~|60<br>~~a~~|—<br>~~a~~|mV<br>~~a~~|
|tOLD<br>~~a~~|OLD Active Time<br>~~a~~|fS= 15kHz<br>~~a~~|—<br>~~a~~|4.3<br>~~a~~|—<br>~~a~~|ms<br>~~a~~|
|**Thermal Shutdown**<br>~~So~~|||||||
|TSD<br>~~a~~|Thermal Shutdown Threshold|—|+135|+150|+165|°C|



Note: 5. The drain-source voltage is 80% of VDSS in the aging condition. 

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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B** 

## **Typical Characteristics** (Note 6) 

**Feedback Threshold Voltage vs. Ambient Temperature** 

## **Minimum Operating Voltage vs. Ambient Temperature** 

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3.5<br>3.3<br>| | | | | ft ft fy<br>3.1<br>| | | | | | | |<br>2.9<br>| | | | | | | ff<br>2.7<br>| | | | | | | ff<br>2.5 a<br>2.3 a<br>2.1<br>| | | | | | | |<br>1.9<br>| | | | | | | |<br>1.7<br>| | | | | | |<br>1.5<br>| | ft | | Pt<br>-40 -20 0 20 40 60 80 100 120<br>Ambient Temperature (C)<br>VFB (V)<br>**----- End of picture text -----**<br>


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8.0<br>7.9<br>Pp | | | ft ft tt<br>7.8<br>po | | | ft tt<br>7.7<br>p | | | ft tt<br>7.6<br>mj | | | | | td<br>7.5 pet<br>7.4 ee eee<br>7.3<br>Po<br>7.2<br>p | | | ft tt<br>7.1<br>p | | | ft |<br>7.0<br>a<br>-40 -20 0 20 40 60 80 100 120<br>Ambient Temperature (C)<br>VCC_UVLO (V)<br>**----- End of picture text -----**<br>


## **Standby Current vs. Ambient Temperature** 

**Latch Off Current vs. Ambient Temperature** 

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50 150<br>45 140<br>| | | | | | ft fy | | | | | ft | fy<br>40 130<br>Pp | | | | | | | | | | | | | |<br>35 120<br>Pp | | | | hc | poof<br>30 110<br>ee, > eee<br>25 100<br>| | ee ev] } | | tt |<br>20 90<br>pe p | | | | ff |<br>15 80<br>Pp | | | | hc | Pp | | | | | tt<br>10 70<br>Pp | | | | tl | Pp | | | | ft tl |<br>5 60<br>ee ee eee Pp | | | | ft |<br>0 50<br>pF | ff | | | | ft | |<br>-40 -20 0 20 40 60 80 100 120 -40 -20 0 20 40 60 80 100 120<br>Ambient Temperature (C) Ambient Temperature (C)<br>Operating Current vs. Ambient Temperature  Peak Current vs. Ambient Temperature<br>450 600<br>435 580<br>| | | | | ft ft ff | | | | | ft | ff<br>420 560<br>| | | | | ft Pp | | | | | | |<br>405 540<br>| | | | | ft eeeee<br>390 520<br>PN poPN<br>375 a Ae) 500 Po<br>360 480<br>P| | P| | | cP po<br>345 460<br>eee Ae Pp | | | | ft | UN<br>330 440<br>Nee eee Pp | | | | ft ft |<br>315 420<br>| | | | | ft Pp | | | | ft ft |<br>300 400<br>| | PT | | | | ff | tt<br>-40 -20 0 20 40 60 80 100 120 -40 -20 0 20 40 60 80 100 120<br>Ambient Temperature (C) Ambient Temperature (C)<br>A)<br>(ICC_NL<br> (mA)<br>IPK_MAX<br>A)<br><br> (<br>ICC_FULL<br>A)<br><br> (<br>ICC_LATCH<br>**----- End of picture text -----**<br>


Note:  6. These electrical characteristics are tested under DC condition. The ambient temperature is equal to the junction temperature of the device. 

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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

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AL17150-10B<br>Function Description<br>Overall Introduction<br>The AL17150-10B is a universal AC input step down regulator. Max peak current limitation and driving frequency vary as the load change can get<br>excellent efficiency performance at light load and improve the overall efficiency of system. Working with a single winding inductor and integrating<br>500V/1A MOSFET internal can make it use fewer external components and create a low BOM cost solution. Figure 1 shows a typical application<br>example of a Buck topology power supply.<br>R1<br>FB<br>L1 D4<br>L RF1 D1 VCC C4<br>Drain R2 C5<br>C3 L2 VO+<br>S<br>C1 C2 AL17150-10B<br>C6 R3<br>D3<br>D2<br>N<br>VO-<br>Figure 1. Typical Application Circuit<br>Converter Operation<br>; [|<br>NEW PRODUCT<br>**----- End of picture text -----**<br>


## **Startup and Under Voltage Lock-Out** 

The IC control voltage VCC is charged by internal high voltage regulator. When the VCC voltage is charged to 8.5V, IC startups and the internal high voltage regulator is turned off; when the VCC voltage drops below 8.2V, the internal high voltage regulator turns on again to charge the external VCC capacitor. 

When fault conditions happen, such as some protections like overload faults, short-circuit faults, over temperature faults, and open-loop faults, the AL17150-10B stops switching. Afterwards an internal current source IBP_LATCH discharges the external BP capacitor. The internal high-voltage regulator will not turn on again until the voltage on BP capacitor drops below VBP_RESTART (4.5V). The restart time interval is proportional to the capacitance of external BP capacitor—the larger capacitance of the external BP capacitor, the longer restart time. 

The restart time after a fault is about 

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   ………………………………………… (1)<br> is actual voltage value of VCC pin at the time of fault, which is between VCC_ON and VCC_OFF.CC_ON and VCC_OFF. and VCC_OFF.CC_OFF.<br>CC. .<br>VCC VCC_OFF=8.5V<br>VCC_ON=8.2V<br>VCC_STOP=4.5V<br>ON ON ON ON ON<br>HV<br>Regulator OFF OFF OFF OFF OFF<br>**----- End of picture text -----**<br>


Where: 

VCC_FAULT is actual voltage value of VCC pin at the time of fault, which is between VCC_ON and VCC_OFF.CC_ON and VCC_OFF. and VCC_OFF.CC_OFF. 

Figure 2 shows the typical waveform of VCC. . 

Figure 2. VCC Waveform and Internal HV Regulator ON/OFF Status 

## **Auxiliary VCC Supply** 

If the output voltage is higher than the voltage of VCC_ON, an auxiliary VCC supply can be implemented to reduce overall power consumption by connecting a resistor (R4) between C2 and C3. A standby power of less than 50mW can be achieved especially in a no-load condition. 

6 of 13 **www.diodes.com** 

AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

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AL17150-10B<br>Function Description  (continued)<br>Figure 3 shows the low standby power circuit with the auxiliary VCC supply.<br>R4<br>R1<br>FB<br>L1 D4<br>L RF1 D1 VCC C4<br>Drain R2 C5<br>C3<br>L2 VO+<br>S<br>C1 C2 AL17150-10B<br>C6 R3<br>D3<br>D2<br>N<br>VO-<br>Figure 3. Low Standby Power Circuit with Auxiliary VCC Supply<br>The value of R4 can be determined by the following equation:<br>…………………………………………………………………… (2)<br>pe Constant Voltage Operation<br>The AL17150-10B is a step down regulator with 500V/1A MOSFET internal. It can be used in Buck circuit as shown in the  Typical Application<br>Circuit .<br>In the course of running IC, when the voltage of FB pin is below the reference voltage (2.5V), the internal integrated MOSFET turns ON. The peak<br>current limit and the initial inductance current value altogether with the input voltage determine the ON period time. When the current reaches<br>peak current limit, the internal integrated MOSFET turns OFF. The inductor current charges the sampling capacitor (C5) and the output capacitor<br>(C6) via the freewheeling diode D4 and D3 respectively. The sampling capacitor voltage is the mapping of the output voltage. The output voltage<br>can be controlled by sampling the voltage of feedback pin which is derived from the voltage of sampling capacitor. In the OFF stage of internal<br>MOSFET, when the inductor current drops below the output current, the sampling capacitor voltage begins to decrease. When the voltage of<br>feedback pin falls below the reference voltage (2.5V), a new switching cycle begins.<br>Figure 4 shows the detailed operation timing diagrams under Discontinuous Conduction Mode (DCM) and Continuous Conduction Mode (CCM).<br>MOS MOS<br>Diode Diode<br>IL IL<br>Ipk<br>Ipk Io<br>Io<br>Vo Vo<br>VFB VFB<br>2.5V 2.5V<br>Be<br>(1) DCM Mode Operation                                                          (2) CCM Mode Operation<br>NEW PRODUCT<br>**----- End of picture text -----**<br>


Figure 4. Operation Timing of AL17150-10B 

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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B Function Description** (continued) Generally, the output voltage can be described as the following equation: ………………………………………… (3) **Frequency and Peak Current** To maintain high efficiency under different load condition, the AL17150-10B adjusts the switching frequency automatically. The switching frequency can be calculated with Equation 4 for DCM mode operation and Equation 5 for CCM mode operation. ……………………………………………………… (4) ……………………………………………………… (5) In the meantime, the peak current of the inductor (IPK) is determined by the following equation: ……………………………… (6) In the Equation 6, tOFF is internal MOSFET OFF time of the IC, and 500mA is peak current limit and 15.5μs is the minimum tOFF value. As the load decreases, the switching frequency decreases and the MOSFET OFF time tOFF increases, leading to the decrease of peak current. In no load condition, in which only a dummy load is retained, the frequency and the peak current are both minimized. This helps to reduce the no load power consumption. **Startup Control** The AL17150-10B implements a minimum OFF time control. In normal condition, the minimum OFF time limit is 15.5μs. ~~;~~ | In the startup process, the output voltage is not established and more demagnetizing time is needed. Therefore, the soft start technique is adopted. During the startup process, the minimum MOSFET OFF time varies with three stages, and it gradually drops from 60μs to 30μs, and then to 15.5μs. Each stage contains 128 switching cycles and the startup process will end if the desired output voltage is reached. 

## **EA Compensation** 

To improve load regulation and load transient performance, the AL17150-10B is designed with an Error Amplifier (EA) compensation function. 

The compensation is related to the load condition. With an increasing load, the compensation value increases and the reference voltage of the internal feedback comparator is slightly pulled down. A faster change in the load will lead to a greater compensation step. The output voltage will be regulated back to the desired voltage. This compensation will precisely maintain the output voltage. 

## **Leading-Edge Blanking** 

A narrow spike on the leading edge of the current waveform can usually be observed when the power MOSFET is turned on. A 250ns leadingedge blank is built-in to prevent the false-triggering caused by the turn-on spike. During this period, the current limit comparator is disabled and the gate driver cannot be switched off. 

## **Protection** 

## **Short-Circuit Protection (SCP)** 

The AL17150-10B will shut down when the peak current exceeds the short-circuit protection threshold (800mA). The AL17150-10B will resume operation when the fault is removed. 

## **Over Load Protection (OLP)** 

With the increase of load, the peak current and the switching frequency increase. When the peak current reaches the maximum limitation, and the OFF time is the minimum OFF time, the output voltage drops if the load continues to increase. Similarly, the FB voltage decreases as the output voltage drops. When FB voltage drops below OLP threshold VFB_OLP (1.7V), the internal timer of overload starts to count. Once the overload duration lasts more than the OLP delay time tOLP (170ms), the OLP occurs. 

The time delay setting of OLP should avoid triggering OLP when the system starts up or enters a load transition phase. Therefore it requires that the system startup time must be less than tOLP. The 170ms time delay of tOLP is calculated under the condition of 36kHz operating frequency. The different operating frequency corresponds to different time delay, the time delay calculation under different operating frequency (fs) as follows: 

…………………………………………………… (7) 

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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B Function Description** (continued) **Open Loop Detection** When the VFB FB drops below 60mV, the AL17150-10B will stop working and begin a re-start cycle. The open loop detection is blanked for 64 switching cycles during start-up stage. **Thermal Shutdown (TSD)** The AL17150-10B integrates an internal thermal shutdown protection function. If the IC junction temperature rises above TJSTOP (typical value: +150°C), the Thermal Shutdown (TSD) protection is triggered and the internal MOSFET stops switching. To recover the switching of internal MOSFET, the IC junction temperature has to fall by a hysteresis of +30°C below the TJSTOP. During TSD protection, VCC drops to VCC_RESTART (typical value 4.5V), and then the internal high voltage regulator recharges VCC. **Application and Implementation** The AL17150-10B is a universal high voltage step-down regulator. Figure 1 shows a typical application for reference. The application can be used in a wide variety of home appliances and industrial control devices, or any other application where mains isolation is not required. **Input Stage** The input stage consists of RF1, D1, D2, C1, C2 and L1, Resistor RF1 is a fusible resistor. RF1 limits the inrush current, and also provides protection in case any component failure causes a short circuit. Value for its resistance is generally selected from 4.7Ω to 15Ω. A half-wave rectifier is implemented with the diode D1. It is a general purpose 1A/1000V diode. D2 is added for improving common-mode conducted EMI noise performance and can be removed if not needed. Components C1, L1, C2 form a Pi EMI filter; Capacitors C1 and C2 also act as storage capacitors for the high-voltage input DC voltage. When using the half-wave rectifier, set the input capacitor 3μF/W for the universal input condition. When using the full-wave rectifier, choose a ; smaller capacitor. To avoid thermal shutdown, capacitance selection must avoid the minimum DC voltage below 70V. And if passing surge test is | needed for the converter, adjusting input capacitance can help to meet different surge test requirements. 

When the VFB FB drops below 60mV, the AL17150-10B will stop working and begin a re-start cycle. The open loop detection is blanked for 64 switching cycles during start-up stage. 

## **VCC Capacitor** 

The VCC capacitor (C3) acts as the storage capacitor for the IC internal power supply. A typical selection is a 2.2F/10V SMD ceramic capacitor. 

## **Inductor** 

In Buck converter, the inductor peak to peak current ripple can be obtained with Equation 8 for DCM mode operation and with Equation 9 for CCM mode operation. 

_…………………………………………………………… (8)_ ………………………………………………… (9) 

The internal MOSFET turn-on time (tON) can be given by Equation 10 and it is determine by the peak current limit and the inductor. 

~~…~~ …………………………………………………… (10) 

To guarantee normal operation, tON must be bigger than tLEB with margin. 

The Buck converter reaches maximum power when the off-time equals the minimum off time (tMINOFF). Thus the maximum output power can be calculated with Equation 11 for DCM mode operation and with Equation 12 for CCM mode operation. 

……………………………… (11) …………………………………………… (12) 

Since the on-time is generally far smaller than the off-time, the approximation in Equation 8 can be reasonable for estimation. 

To design an inductor, the desired maximum output power is given according to the output specification. The desired peak current is also estimated, no more than 500mA. Since tMINOFF is 15.5μs, a minimum inductance can be calculated with Equation 8. The inductance should be checked with the above equations, and it should be adjusted to ensure that the on-time limitation is satisfied and the desired peak current under full load is met. Some inductance margin is also needed for tolerance. 

With the inductance and its peak current value, a standard off-the-shelf inductor can be used to reduce cost. 

9 of 13 **www.diodes.com** 

AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B Function Description** (continued) **Freewheeling Diode** The maximum reverse voltage that the diode would experience during normal operation is given by the following equation. …………………………………………… (13) For a universal AC input application, the 265VAC, thus VD-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection. AC, thus VD-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection. , thus VD-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection. D-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection.  value is 375V. Considering a margin of 20%, a 600V diode is a general selection. A fast recovery diode is required for the Buck application. And the reverse recovery time should be kept less than 100ns. **Output Capacitor** The output capacitor maintains the DC output voltage, and the value impacts the output ripple. The output voltage ripple can be estimated with Equation 14 for DCM mode operation and Equation 15 for CCM mode operation. ………………………………… (14) (14) ………………………………………… (15)(15) Where fS is the switching frequency, and RESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to S is the switching frequency, and RESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to  is the switching frequency, and RESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to ESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to  is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to hundreds of μF. If the total ripple is higher than the requirement, increasing the capacitance and reducing the ESR can be helpful. **Dummy Load** The output requires a dummy load (R3) to maintain the load regulation under no-load condition. This can ensure sufficient inductor energy to charge the sample-and-hold capacitor to detect the output voltage. Most applications can use a 3mA dummy load, and the dummy load can be ~~;~~ adjusted according to the regulation. Increasing the dummy load adversely affects the efficiency and no-load consumption. | 

For a universal AC input application, the 265VAC, thus VD-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection. AC, thus VD-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection. , thus VD-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection. D-MAX value is 375V. Considering a margin of 20%, a 600V diode is a general selection.  value is 375V. Considering a margin of 20%, a 600V diode is a general selection. A fast recovery diode is required for the Buck application. And the reverse recovery time should be kept less than 100ns. 

The output capacitor maintains the DC output voltage, and the value impacts the output ripple. The output voltage ripple can be estimated with Equation 14 for DCM mode operation and Equation 15 for CCM mode operation. ………………………………… (14) (14) ………………………………………… (15)(15) Where fS is the switching frequency, and RESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to S is the switching frequency, and RESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to  is the switching frequency, and RESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to ESR is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to  is ESR of output capacitor. For a typical application, the capacitor value can ranges from 47μF to hundreds of μF. If the total ripple is higher than the requirement, increasing the capacitance and reducing the ESR can be helpful. 

The output requires a dummy load (R3) to maintain the load regulation under no-load condition. This can ensure sufficient inductor energy to charge the sample-and-hold capacitor to detect the output voltage. Most applications can use a 3mA dummy load, and the dummy load can be adjusted according to the regulation. Increasing the dummy load adversely affects the efficiency and no-load consumption. 

**Feedback Path** R1 and R2 form a resistor divider that determines the output voltage. The values of R1 and R2 should be set to maintain the FB voltage at 2.5V. The typical value for R2 is between 5kΩ to10kΩ and precision of R1 and R2 must be 1%. ~~…~~ ………………………………… (16) For low output voltage application, the difference caused by D3 and D4 cannot be neglected and R1 should be set larger to compensate the difference. Since the diode forward voltage is positively related with the current flows through it and the current through D3 is much higher than D4, VD3 is higher than VD4. 

The feedback capacitor provides a sample and hold function and the capacitance selection should follow the Equation 17 as below.. ~~…~~ ……………………………………… (17) 

The capacitor C5 is discharged with a time constant that is and can be regarded as the load time constant. If is larger than , voltage on C5 could be larger than VOUT when sampling, leading to wrong sampling of VOUT and wrong regulation. And if is too small, voltage on FB pin would drop to 1.7V before the next MOSFET OFF time come and thus mis-trigger Over Load Protection(OLP). Therefore, an appropriate value of C5 is important. 

## **Layout Guidelines** 

The PCB layout is important to achieve reliable operation, good EMI, and thermal performance. Follow these guidelines to optimize performance. 

- Minimize the loop area formed by the input capacitor, IC part, freewheeling diode, inductor and output capacitor. 

- The copper area of the FB signal should be minimized to reduce coupling to feedback path. 

- A several-hundred pF capacitor should be added between the FB and S pins, and be placed as close as to the FB pin as possible. 

- Place the power inductor far away from the input filter. 

- Connect the exposed pad with the Drain pin to a large copper area to improve thermal performance. 

10 of 13 **www.diodes.com** 

AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B Ordering Information AL17150-10B  X** – **X** Product Name Package Packing S7: SO-7 13: 13'' Tape and Reel **13” Tape and Reel Part Number Package Code Package Quantity Part Number Suffix** AL17150-10BS7-13 S7 SO-7 4000/Tape & Reel -13 **Marking Information Package Type: SO-7 (Top View)** 7 FL 6 5 Logo YY : Year : 19, 20, 21 ~ Marking ID **17150-10B** WW : Week : 01~52; 52 represents 52 and 53 week **YY WW X X** X X : Internal Code 1 2 3 4 To. ~~[E]~~ AL17150-10B 11 of 13 Document number: DS41338 Rev. 1 - 2 **www.diodes.com** © Diodes Incorporated 

October 2019 © Diodes Incorporated 

**AL17150-10B** 

**Package Outline Dimensions** (All dimensions in mm(inch).) 

Please see http://www.diodes.com/package-outlines.html for the latest version. 

**Package Type: SO-7** 

**==> picture [335 x 283] intentionally omitted <==**

**----- Start of picture text -----**<br>
5.800(0.228)<br>1.350(0.053)<br>6.200(0.244) 1.750(0.069)<br>0.330(0.013 )<br>0.510(0.020 )<br>2.54(0.100)<br>TYP 4.700(0.185)<br>5.100(0.201)<br>1.270(0.050)<br>TYP<br>wel<br>0.080(0.003)<br>0.250(0.010)<br>tt = a<br>3.800(0.150) 1.250(0.049)<br>4.000(0.157) 1.500(0.059)<br>0.350(0.014)<br>TYP<br>45°<br>0.450(0.017) 0.150(0.006)<br>Option 1 0.800(0.031) 0.250(0.010)<br>Option 2<br>Note: Eject hole, oriented hole and mold mark is optional.<br>0 °<br>8 °<br>**----- End of picture text -----**<br>


## **Suggested Pad Layout** 

Please see http://www.diodes.com/package-outlines.html for the latest version. 

**Package Type: SO-7** 

**==> picture [121 x 104] intentionally omitted <==**

**----- Start of picture text -----**<br>
G Z<br>E1<br>Y<br>E X<br>**----- End of picture text -----**<br>


|**Dimensions**|**Z**<br>**(mm)/(inch)**|**G**<br>**(mm)/(inch)**|**X**<br>**(mm)/(inch)**|**Y**<br>**(mm)/(inch)**|**E**<br>**(mm)/(inch)**|**E1**<br>**(mm)/(inch)**|
|---|---|---|---|---|---|---|
|Value|6.900/0.272|3.900/0.154|0.650/0.026|1.500/0.059|1.270/0.050|2.540/0.100|



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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated 

**AL17150-10B IMPORTANT NOTICE** DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated website, harmless against all damages. Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel. Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks. This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the final and determinative format released by Diodes Incorporated. **LIFE SUPPORT** Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A.   Life support devices or systems are devices or systems which: | 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B.   A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright © 2019, Diodes Incorporated **www.diodes.com**[;] 

Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A.   Life support devices or systems are devices or systems which: 

2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. 

Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. 

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AL17150-10B Document number: DS41338 Rev. 1 - 2 

October 2019 © Diodes Incorporated