# Circuit diagram of SDS011 PM sensor

**URL:** https://forum.sensor.community/t/circuit-diagram-of-sds011-pm-sensor/145
**Category:** Uncategorized
**Created:** [December 29, 2020, 7:35pm UTC](https://forum.sensor.community/t/circuit-diagram-of-sds011-pm-sensor/145 "2020-12-29T19:35:50Z")
**Posts on this page:** 5
**Page:** 3

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### Author: ![irukard](https://forum.sensor.community/user_avatar/forum.sensor.community/irukard/32/12_2.png) [@irukard](https://forum.sensor.community/u/irukard)
#### Post date: [March 16, 2021, 10:37pm UTC](https://forum.sensor.community/t/circuit-diagram-of-sds011-pm-sensor/145/41 "2021-03-16T22:37:33Z")

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Yep. My UT61C can go as low as 40nF. pF is way out of it’s league. Maybe it’s time for new multimeter.

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### Author: ![Mogwaika](https://forum.sensor.community/user_avatar/forum.sensor.community/mogwaika/32/227_2.png) [@Mogwaika](https://forum.sensor.community/u/Mogwaika)
#### Post date: [March 16, 2021, 11:03pm UTC](https://forum.sensor.community/t/circuit-diagram-of-sds011-pm-sensor/145/42 "2021-03-16T23:03:35Z")

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40 nF is maximum in lower scale.  
Yours have resolution 10 pF and accuracy 3%, +/- 50 pF. And may be capacitance 50 pF is too small for it.

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### Author: ![irukard](https://forum.sensor.community/user_avatar/forum.sensor.community/irukard/32/12_2.png) [@irukard](https://forum.sensor.community/u/irukard)
#### Post date: [March 17, 2021, 10:21am UTC](https://forum.sensor.community/t/circuit-diagram-of-sds011-pm-sensor/145/43 "2021-03-17T10:21:56Z")

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> [@Mogwaika](#):
>
> I desoldered C1 from sds and my multimeter shows ~50 pF.

In that case most probable value is 47pF like Samsung CL10C470JB8NNNC (LCSC C1671).

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<div class="post-metadata">

### Author: ![irukard](https://forum.sensor.community/user_avatar/forum.sensor.community/irukard/32/12_2.png) [@irukard](https://forum.sensor.community/u/irukard)
#### Post date: [March 17, 2021, 11:03am UTC](https://forum.sensor.community/t/circuit-diagram-of-sds011-pm-sensor/145/44 "2021-03-17T11:03:20Z")

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I’ve uploaded schematics to github:

> **[irukard/NovaFitness-SDS011-Reverse-Engineering](https://github.com/irukard/NovaFitness-SDS011-Reverse-Engineering)**
>
> Reversed engineered SDS011 schematics. Contribute to irukard/NovaFitness-SDS011-Reverse-Engineering development by creating an account on GitHub.

What type of license for schematics should I use? CC-SA-BY or something else like TAPR OHL or CERN OHL?

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<div class="post-metadata">

### Author: ![Mogwaika](https://forum.sensor.community/user_avatar/forum.sensor.community/mogwaika/32/227_2.png) [@Mogwaika](https://forum.sensor.community/u/Mogwaika)
#### Post date: [March 17, 2021, 5:37pm UTC](https://forum.sensor.community/t/circuit-diagram-of-sds011-pm-sensor/145/45 "2021-03-17T17:37:03Z")

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I try to do some simulations in tina-ti. That is response of 10 ns 100 uA rectangle current.  
I think real C1 is 10 - 50 pF.

 ![IMG_20210301_032758](https://forum.sensor.community/uploads/default/original/1X/76a6e713e6adb32670f839fc4a88d78856c89325.jpeg)  
real response of tia (yellow channel) ~150 us (but may be signal not 100 ns but 1000 or more)  
 ![Untitled](https://forum.sensor.community/uploads/default/original/1X/2d01ef26e4abc87b705ff3343e3674bb037b0d77.png) ![C1_1p_50p](https://forum.sensor.community/uploads/default/original/1X/3643a444649b74c0ad7c65a2346177b425459d49.png) ![C1_10p_50p](https://forum.sensor.community/uploads/default/original/1X/2a3b99ea6157515dfab4bdda88ed7011f30adf1d.png) ![C1_300f_100p](https://forum.sensor.community/uploads/default/original/1X/985ebd3d5ecbc6a2ec328c2c1073a1f398f75218.png)

This design have some different photodiode connection, because in normal schematic there are some errors.

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