SDP36-500PA

## **Preliminary Datasheet SDP3x-Analog** Differential Pressure Sensor with Analog Output 

- Smallest size enables portable applications 

- Reflow solderable – Pick & Place 

- Configurable analog output 

- Calibrated and temperature compensated 

- Excellent repeatability, no drift 

## **Product Summary** 

The SDP3x sensor family is Sensirion’s series of small differential pressure sensors designed for high-volume applications where size is a key requirement. It builds on the next generation CMOSens® sensor chip that is at the heart of Sensirion’s new differential pressure and flow sensing platform. 

The analog SDP3x sensors offer a calibrated and temperature compensated analog voltage output. The output signal is configurable: different measurement speeds, output curves and temperature compensations can be selected – even dynamically during operation mode. 

## **Benefits of Sensirion’s CMOSens[®] Technology** 

- High reliability and long-term stability 

- Best signal to noise ratio 

- Industry-proven technology with a track record of more than 15 years 

- Designed for mass production 

- High process capability 

## **Content** 

1. Sensor Performance .............................................................. 2 2. Specifications ......................................................................... 3 3. Pin Assignment ...................................................................... 4 4. Package Outline..................................................................... 6 5. Soldering ................................................................................ 7 6. Shipping Package .................................................................. 8 7. Ordering Information .............................................................. 8 Revision History .............................................................................. 8 Important Notices ........................................................................... 9 Headquarters and Subsidiaries ...................................................... 9 

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**1.1 Differential Pressure Specification[1]** 

## **1. Sensor Performance** 

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Parameter  Configuration  SDP36  SDP37<br>Measurement range  [2] Linear  - 50 to + 500 Pa  - 12.5 to + 125 Pa<br>(-0.2 to 2.0 in. H2O) (-0.05 to ½ inch H2O)<br>Square Root  - 500 to + 500 Pa  - 125 to + 125 Pa<br>a (± 2.0 in. H2O) (± ½ inch H2O)<br>pf Zero point accuracy [ 3,4,5] 0.1 Pa [ 5] 0.08 Pa [ 5]<br>pf Span accuracy [ 3,4,5] 3% of reading [ 5] 3% of reading [ 5]<br>pf Zero point repeatability [ 4,5] 0.03 Pa [ 5] 0.025 Pa [ 5]<br>a Span repeatability [ 4,5] Ge 0.5% of reading [ 5] 0.5% of reading [ 5]<br>Span shift due to temperature<br>< 0.5% of reading per 10°C  < 0.5% of reading per 10°C<br>variation<br>pf Offset stability < 0.01 Pa/year  < 0.01 Pa/year<br>Slow  < 9 ms<br>Response time (τ63)<br>Fast  < 5 ms<br>rr Pe<br>. GO ae<br>pf Internal digital resolution  16 bit<br>pf Calibrated for  Air, N2<br>pa Media compatibility Air, N2, O2, non-condensing<br>Calibrated temperature range  -20 °C to +85 °C<br>pO<br>**----- End of picture text -----**<br>


> 1 Unless otherwise noted, all sensor specifications are valid at 25°C with VDD = 3.3 V and absolute pressure = 966 mbar. 

> 2 For other pressure ranges contact Sensirion 

> 3 Includes repeatability 

> 4 Total accuracy/repeatability is a sum of zero-point and span accuracy/repeatability. 

> 5 Output voltage integral non linearity and output voltage noise are not included. Note that the effect of output voltage integral non linearity and output voltage noise on accuracy is highly dependent on the output configuration (linear or square root). 

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## **2. Specifications** 

## **2.1 Electrical Specifications** 

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||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|ee|Parameter|Symbol|rs nD|Condition|Min.|I|Typ.|Max.|Units|Comments|
|Supply|
|For 5V supply contact|
|Supply Voltage|VDD|3.0|3.3|3.6|V|Sensirion|
|ee|ee|es|ee|es|ee|ee|
|Power-up/down level|VPOR|2.3|2.5|2.7|V|
|Minimum voltage|
|VDD ramp up slew|VDD, ramp|0.2|V/ms|ramp up slew when|
|powering up SDP3x|
|Ss|ee|
|es|Supply current|IDD|nD|(On|3.8|5.5|mA|
|Ratiometric analog voltage output|
|re|Output range|ns|nD|0.1|I|0.9|VDD|
|ss|Resistive load|to|GND|10|[1]|kOhm|
|a|Resistive load to VDD|nD Inn|1000|In|D|II|IS|(OU|kOhm|
|es|Capacitive load|Cload|100|nF|
|Output voltage Integral|
|5|mV|
|Non Linearity (INL)|
|es|eeRnes|eeI|
|Output voltage noise|
|0.5|mV|
|e|(RMS)|ee|e|e|eee|
|2.2|Timing Specifications|
|Parameter|Symbol|Condition|Min.|Typ.|Max.|Units|Comments|
|Time to first reliable|
|Power-up time|tPU|25|ms|measurement|
|2.3|Mechanical Specifications|
|Parameter|Symbol|Condition|Min.|Typ.|Max.|Units|Comments|
|Allowable overpressure|[2]|Pmax|1|bar|
|Rated burst pressure|Pburst|3|bar|
|Weight|W|0.2|g|
|2.4|Materials|
|Parameter|
|Wetted materials|glass (silicon nitride, silicon oxide), LCP,|green epoxy-based mold compound, epoxy-based resins|
|REACH, RoHS|REACH and RoHS compliant|

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## **2.5 Absolute Maximum Ratings** 

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|||||
|---|---|---|---|
|Parameter|Rating|Units|
|Supply Voltage VDD|-0.3 to 4.5|V|
|Max Voltage on pins (Inputs)|-0.3 to VDD+0.3|V|
|Input current on any pin|±70|mA|
|Operating temperature range|[3]|-20 to +85|°C|
|Storage temperature range|[4]|-40 to +85|°C|
|Max. humidity for long term exposure|40°C dew point|
|ESD HBM (human body model)|2|kV|

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> 1 For a resistive load to GND less than 100kOhm a 1nF capacitor to GND on the AOUT is recommended 

> 2 Allowable overpressure during operation. Refer to the SDP selection guide for pressure dependency of the measured signal. Fast absolute pressure changes on both ports can result in dynamic effects on the sensor signal. For higher overpressures or continuous high overpressures contact Sensirion. 

> 3 For Air and N2. Long term exposure to high temperatures and (high concentrations of) O2 can reduce the product lifetime 

> 4 For long term storage in Tape and Reel, please refer to the SDP3x handling instructions 

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## **3. Pin Assignment** 

The SDP3x consists of a QFN package with a plastic cap covering the top and providing the pneumatic connections to the sensor. The pin assignments of the SDP3x-Analog can be found in Table 1. 

|Pin no.<br>~~a~~|Name<br>~~a~~|Description<br>~~a~~|—————_<br> lOf<br>Tou<br>TO}<br>~<br>iz<br> £8<br>a<br>6]|
|---|---|---|---|
|1<br>~~a~~|GND<br>~~a~~|Connect to ground<br>~~a~~||
|2<br>~~a~~<br>~~——}—~~<br>~~ey~~|GND<br>~~a~~<br>~~——}—~~<br>|Connect to ground<br>~~a~~<br>~~——}—~~<br>||
|3<br>~~a~~<br>~~——}—~~<br>~~ey~~|GND<br>~~a~~<br>~~——}—~~<br>|Connect to ground<br>~~a ~~<br>~~——}—~~<br>||
|4<br><br>~~——}—~~<br>~~eyff~~|BWS<br><br>~~——}—~~<br>~~ff~~|Bandwidth selection input<br> <br>~~——}— ~~<br>~~ff~~||
|5<br><br>~~eyff~~<br>~~ey~~|TCS<br><br>~~ff~~<br>|Temperature compensation selection input<br>ExpectedMarch 2017<br> <br>~~ff~~<br>||
|6<br>~~ff~~<br>~~ey~~|GND<br>~~ff~~<br>|Connect to ground<br>~~ff~~<br>||
|7<br>~~ey———~~|VDD<br>~~———~~|VDD Supply<br>~~———~~||
|8<br>~~———~~<br>~~ee~~|OCS<br>~~———~~<br>~~es~~|Output curve selection input<br>~~———~~<br>~~es~~||
|9<br>~~ee~~|AOut<br>~~es~~|Ratiometric analog voltage output<br>~~es~~<br>~~———_]~~||
|10<br>~~ee~~|GND<br>~~es~~|Connect to ground<br>~~es~~<br>~~———_]~~||
|11<br>~~es~~|GND|Connect to ground<br>~~———_] ~~||
|12-16<br>~~es~~|-|Reserved. Do not connect||



_**Table 1:** SDP3x-Analog pin assignment (bottom view)._ 

## **3.1 Power Pins (VDD, GND)** 

The power supply pins must be decoupled with a 100 nF capacitor that shall be placed as close to the sensor as possible. 

## **3.2 OCS: Output Curve Selection Input** 

|Config.|Polarity|Description|Conversion to physical values<br>AOut[V], VDD[V], Differential Pressure (DP) [Pa]|Conversion to physical values<br>AOut[V], VDD[V], Differential Pressure (DP) [Pa]|
|---|---|---|---|---|
|Linear|Low<br>(GND)|Analog output is configured as a linear<br>output. The sensor is not fully bi-<br>directional in this configuration: -10% full-<br>scale to 100% full scale.<br>a 75%<br>ea<br>= 50%<br>a<br>Q<br>25%<br>-20%<br>20%<br>60%<br>100%<br>DP (%FS)|SDP36<br>(500Pa)|𝐷𝑃= 750 ∙𝐴𝑂𝑢𝑡<br>𝑉𝐷𝐷<br>−150|
||||SDP37<br>(125Pa)|𝐷𝑃= 190 ∙𝐴𝑂𝑢𝑡<br>𝑉𝐷𝐷<br>−38|
|Square<br>Root|High<br>(VDD)|Analog output is a fully bi-directional<br>output with square root conversion. The<br>benefits are that the bidirectional output<br>has a more stable zero point and higher<br>sensitivity at lower pressures<br>a<br>100.0% <br>(a)<br><<br>75.0%<br>B<br>50.0%<br>xt<br>0%<br>-100%<br>-50%<br>0%<br>50%<br>100%<br>DP (%FS)|SDP36<br>(500Pa) <br> ~~|=~~|𝐷𝑃=  𝑠𝑖𝑔𝑛~~(~~𝐴𝑂𝑢𝑡<br>𝑉𝐷𝐷<br>−0.5) ∙~~(~~<br>𝐴𝑂𝑢𝑡<br>𝑉𝐷𝐷∙0.4<br>−1.25)<br>2<br>∙525<br>~~|=~~|
||||SDP37<br>(125Pa)|𝐷𝑃=  𝑠𝑖𝑔𝑛~~(~~𝐴𝑂𝑢𝑡<br>𝑉𝐷𝐷<br>−0.5) ∙~~(~~<br>𝐴𝑂𝑢𝑡<br>𝑉𝐷𝐷∙0.4<br>−1.25)<br>2<br>∙133|



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## **3.3 TCS: Temperature Compensation Selection Input** 

|Configuration|Polarity|Description|
|---|---|---|
|Temperature<br>compensation for<br>mass flow|Low (GND)|In this configuration temperature compensation is optimized for applications where<br>mass flow measurements in bypass are performed|
|Temperature<br>compensation for<br>differentialpressure|High (VDD)|In this configuration the analog output signal is temperature compensated for<br>differential pressure. This configuration is recommended for applications where real<br>differentialpressuremeasurements arerequired.|



For more information about temperature compensation for differential pressure sensors, for example volume flow measurements in bypass, please refer to the selection guide in the differential pressure download center on our website. 

## **3.4 BWS: Bandwidth Selection Input** 

|Configuration|Polarity|Description|
|---|---|---|
|Fast|Low (GND)|In this configuration the chip will output the differential pressure value on the analog<br>output with the highest possible bandwidth and lowest latency. This configuration is<br>recommended to be used in use cases where small changes need to be detected<br>as quickly as possible.<br>The response time in this configuration is less than 5ms|
|Slow|High (VDD)|In this configuration extra averaging is in place in order to achieve an excellent<br>signal to noise ratio.<br>The response time in this configuration is less than 9ms|



## **3.5 AOut Pin** 

The AOut pin gives out an analog ratiometric voltage, representing the measured differential pressure value. Please note the resistive and capacitive loads as mentioned in section 2.1. 

Formulas for converting AOut [V] to differential pressure [Pa] can be found in section 3.2. 

## **3.6 Die Pad (Center Pad)** 

The die pad or center pad is visible from below and located in the center of the package. It is internally connected to GND and therefore there are no electrical constraints on connecting or not connecting the die pad to GND. For mechanical stability it is recommended to solder the center pad to the PCB. 

The hole in the middle of the die pad must stay open during soldering. 

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## **4. Package Outline** 

_**Figure 1:** SDP3x. All dimensions in mm._ 

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## **5. Soldering** 

~~i~~ Recommended land pattern 

The solder mask is understood to be the insulating layer on top of the PCB covering the copper traces. It is recommended to design the land pattern as a Non- Solder Mask Defined (NSMD) type. 

~~|~~ Recommended stencil aperture 

The sensor must enter the reflow process only once, with a minimal temperature and exposure time. When both sides of the PCB are reflow soldered or multiple reflow runs are required, the sensor must be soldered in the last soldering run. In any case the temperature should not exceed 260°C; temperatures above 200°C should be limited in time to a maximum of 150 seconds. 

Ensure that the ports of the sensor are well protected during assembly and soldering so that no dust, solder flux or other liquids can enter the flow channel. In no case, a board wash shall be applied. Therefore it is strongly recommended to use “noclean” solder paste. 

It is important to note that the diced edge or side faces of the I/O pads may oxidize over time, therefore a solder fillet may or may not form. Hence there is no guarantee for solder joint fillet heights of any kind. 

Refer to the SDP3x handling instructions on our website for more details. 

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## **6. Shipping Package** 

SDP3x are provided in tape & reel shipment packaging. Standard packaging size is 1500 or 250 units per reel. The drawing of the packaging tapes with sensor orientation is shown in _Figure 2_ . 

_**Figure 2:** Sketch of packaging tape and sensor orientation. Header tape is to the right and trailer tape to the left on this sketch_ 

## **7. Ordering Information** 

Use the part names and product numbers shown in the following table when ordering SDP3x differential pressure sensor. For the latest product information and local distributors, visit www.sensirion.com. 

|Part name|Part name<br>Description / Output|Product number|Packaging|Tape & Reel size|
|---|---|---|---|---|
|SDP36|Analog, 500Pa|1-101471-01|Tape & Reel(QFN Quad 2 configuration)|1500|
|||1-101571-01|Tape & Reel(QFN Quad 2 configuration)|250|
|SDP37|Analog, 125Pa|1-101497-01|Tape & Reel(QFN Quad 2 configuration)|1500|
|||1-101572-01|Tape & Reel(QFN Quad 2 configuration)|250|



## **Revision History** 

|Date|Author|Version|Version<br>Changes|
|---|---|---|---|
|21.12.2015 ANB|21.12.2015 ANB|V0.1|First Draft|
|31.01.2016 ANB|31.01.2016 ANB|V0.2|Firstpreliminaryversion|
|02.02.2016 ANB|02.02.2016 ANB|V0.3|Minor updates|
|04.05.2016 ANB|04.05.2016 ANB|V0.4|SDP37 added. Minor updates|
|06.01.2017 ANB|06.01.2017 ANB|V0.5|Reel size of 250pcs added.|



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## **Important Notices** 

## **Warning, personal injury** 

**Do not use this product as safety or emergency stop devices or in any other application where failure of the product could result in personal injury (including death). Do not use this product for applications other than its intended and authorized use. Before installing, handling, using or servicing this product, please consult the datasheet and application notes. Failure to comply with these instructions could result in death or serious injury.** 

If the Buyer shall purchase or use SENSIRION products for any unintended or unauthorized application, Buyer shall defend, indemnify and hold harmless SENSIRION and its officers, employees, subsidiaries, affiliates and distributors against all claims, costs, damages and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if SENSIRION shall be allegedly negligent with respect to the design or the manufacture of the product. 

## **ESD Precautions** 

The inherent design of this component causes it to be sensitive to electrostatic discharge (ESD). To prevent ESD-induced damage and/or degradation, take customary and statutory ESD precautions when handling this product. 

See application note “Handling Instructions” for more information. 

## **Warranty** 

SENSIRION warrants solely to the original purchaser of this product for a period of 12 months (one year) from the date of delivery that this product shall be of the quality, material and workmanship defined in SENSIRION’s published specifications of the product. Within such period, if proven to be defective, SENSIRION shall repair and/or replace this product, in SENSIRION’s discretion, free of charge to the Buyer, provided that: 

- notice in writing describing the defects shall be given to SENSIRION within fourteen (14) days after their appearance; 

- such defects shall be found, to SENSIRION’s reasonable satisfaction, to have arisen from SENSIRION’s faulty design, material, or workmanship; 

- the defective product shall be returned to SENSIRION’s factory at the Buyer’s expense; and 

- the warranty period for any repaired or replaced product shall be limited to the unexpired portion of the original period. 

This warranty does not apply to any equipment which has not been installed and used within the specifications recommended by SENSIRION for the intended and proper use of the equipment. EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTH HEREIN, SENSIRION MAKES NO WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED. 

SENSIRION is only liable for defects of this product arising under the conditions of operation provided for in the datasheet and proper use of the goods. SENSIRION explicitly disclaims all warranties, express or implied, for any period during which the goods are operated or stored not in accordance with the technical specifications. 

SENSIRION does not assume any liability arising out of any application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. All operating parameters, including without limitation recommended parameters, must be validated for each customer’s applications by customer’s technical experts. Recommended parameters can and do vary in different applications. 

SENSIRION reserves the right, without further notice, (i) to change the product specifications and/or the information in this document and (ii) to improve reliability, functions and design of this product. 

Copyright © 2016-2017, SENSIRION. CMOSens[®] is a trademark of Sensirion All rights reserved 

## Headquarters and Subsidiaries 

SENSIRION AG Laubisruetistr. 50 CH-8712 Staefa ZH Switzerland 

Sensirion Inc., USA phone: +1 805 409 4900 info-us@sensirion.com www.sensirion.com 

Sensirion Korea Co. Ltd. phone: +82 31 337 7700~3 info-kr@sensirion.com www.sensirion.co.kr 

phone: +41 44 306 40 00 fax: +41 44 306 40 30 info@sensirion.com www.sensirion.com 

Sensirion Japan Co. Ltd. Sensirion China Co. Ltd. phone: +81 3 3444 4940 phone: +86 755 8252 1501 info-jp@sensirion.com info-cn@sensirion.com www.sensirion.co.jp www.sensirion.com.cn 

Sensirion Taiwan Co. Ltd. phone:  +41 44 306 40 00 info@sensirion.com 

To find your local representative, please visit www.sensirion.com/contact 

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