# 4\-Channel Gas Sensor AFE

## Description

Four\-channel electrochemical gas sensor signal\-conditioning module based on the TI LMP91000EVM architecture, with shared I2C, per\-channel SPI ADCs, 2\.5V reference, sensor headers, and STM32F767ZI interface\.

## Project Details

- **Owner:** ximena123131
- **Created:** 6/24/2026
- **Last Updated:** 7/13/2026
- **Visibility:** Public

## Key Components

### J1 — [2\.54\-2\*8P针](https://flux.ai/lcsc/2p54-28p~axke.md)

- Datasheet URL: https://www\.lcsc\.com/datasheet/C779499\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=FlkNBAIDRQULVABfFAVZBgZVFVZYBgZSQ1NeBVIFQlExVlNeR1JcVFdURlJdUTsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- License: https://creativecommons\.org/licenses/by/4\.0/
- Symbol Style: parametric\-v1
- LCSC Part Number: C779499
- Manufacturer Name: BOOMELE\(博穆精密\)
- Manufacturer Part Number: 2\.54\-2\*8P针
- JLCPCB Part Class: Extended Part
- Part Type: Pin Headers
- Package or Case Code: HDR\-TH\_16P\-P2\.54\-V\-M\-R2\-C8\-S2\.54

**Pins:**
- 1 [pin 1]
- 10 [pin 10]
- 11 [pin 11]
- 12 [pin 12]
- 13 [pin 13]
- 14 [pin 14]
- 15 [pin 15]
- 16 [pin 16]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
- 5 [pin 5]
- 6 [pin 6]
- 7 [pin 7]
- 8 [pin 8]
- 9 [pin 9]

### J2 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### J3 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### J4 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### J5 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### J6 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### J7 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### J8 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### JP1 — [61300311021](https://flux.ai/adrian95/61300311021~b2y.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.we\-online\.com/components/products/datasheet/61300311021\.pdf
- Manufacturer Name: Wurth Elektronik
- Manufacturer Part Number: 61300311021
- Part Type: Connector
- Package or Case Code: HDRRA3W79P0X254\_1X3\_762X254X269P

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### Q1 — [MMBFJ177LT1G](https://flux.ai/adrian95/mmbfj177lt1g~0s8.md)

- Manufacturer Part Number: MMBFJ177LT1G
- Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/mmbfj177lt1\-d\.pdf
- Role Details: Optional DNP JFET for RE\-WE shorting when off
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Transistor
- Manufacturer Name: ON Semiconductor

**Pins:**
- D [pin 1]
- G [pin 3]
- S [pin 2]

### Q2 — [MMBFJ177LT1G](https://flux.ai/adrian95/mmbfj177lt1g~0s8.md)

- Manufacturer Part Number: MMBFJ177LT1G
- Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/mmbfj177lt1\-d\.pdf
- Role Details: Optional DNP JFET for RE\-WE shorting when off
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Transistor
- Manufacturer Name: ON Semiconductor

**Pins:**
- D [pin 1]
- G [pin 3]
- S [pin 2]

### Q3 — [MMBFJ177LT1G](https://flux.ai/adrian95/mmbfj177lt1g~0s8.md)

- Manufacturer Part Number: MMBFJ177LT1G
- Role Details: Optional DNP JFET for RE\-WE shorting when off
- Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/mmbfj177lt1\-d\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Transistor
- Manufacturer Name: ON Semiconductor

**Pins:**
- D [pin 1]
- G [pin 3]
- S [pin 2]

### Q4 — [MMBFJ177LT1G](https://flux.ai/adrian95/mmbfj177lt1g~0s8.md)

- Manufacturer Part Number: MMBFJ177LT1G
- Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/mmbfj177lt1\-d\.pdf
- Role Details: Optional DNP JFET for RE\-WE shorting when off
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Transistor
- Manufacturer Name: ON Semiconductor

**Pins:**
- D [pin 1]
- G [pin 3]
- S [pin 2]

### U1 — [LMP91000SDE/NOPB](https://flux.ai/adrian95/lmp91000sdenopb~d5k.md)

- Part Type: Integrated Circuit
- Datasheet URL: https://www\.ti\.com/lit/ds/symlink/lmp91000\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: LMP91000SDE/NOPB
- Manufacturer Name: Texas Instruments

**Pins:**
- AGND [pin 7]
- C1 [pin 10]
- C2 [pin 9]
- CE [pin 14]
- DGND [pin 1]
- EP [pin 15]
- MENB [pin 2]
- NC [pin 5]
- RE [pin 13]
- SCL [pin 3]
- SDA [pin 4]
- VDD [pin 6]
- VOUT [pin 8]
- VREF [pin 11]
- WE [pin 12]

### U2 — [LMP91000SDE/NOPB](https://flux.ai/adrian95/lmp91000sdenopb~d5k.md)

- Part Type: Integrated Circuit
- Datasheet URL: https://www\.ti\.com/lit/ds/symlink/lmp91000\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: LMP91000SDE/NOPB
- Manufacturer Name: Texas Instruments

**Pins:**
- AGND [pin 7]
- C1 [pin 10]
- C2 [pin 9]
- CE [pin 14]
- DGND [pin 1]
- EP [pin 15]
- MENB [pin 2]
- NC [pin 5]
- RE [pin 13]
- SCL [pin 3]
- SDA [pin 4]
- VDD [pin 6]
- VOUT [pin 8]
- VREF [pin 11]
- WE [pin 12]

### U3 — [LMP91000SDE/NOPB](https://flux.ai/adrian95/lmp91000sdenopb~d5k.md)

- Part Type: Integrated Circuit
- Datasheet URL: https://www\.ti\.com/lit/ds/symlink/lmp91000\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: LMP91000SDE/NOPB
- Manufacturer Name: Texas Instruments

**Pins:**
- AGND [pin 7]
- C1 [pin 10]
- C2 [pin 9]
- CE [pin 14]
- DGND [pin 1]
- EP [pin 15]
- MENB [pin 2]
- NC [pin 5]
- RE [pin 13]
- SCL [pin 3]
- SDA [pin 4]
- VDD [pin 6]
- VOUT [pin 8]
- VREF [pin 11]
- WE [pin 12]

### U4 — [LMP91000SDE/NOPB](https://flux.ai/adrian95/lmp91000sdenopb~d5k.md)

- Part Type: Integrated Circuit
- Datasheet URL: https://www\.ti\.com/lit/ds/symlink/lmp91000\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: LMP91000SDE/NOPB
- Manufacturer Name: Texas Instruments

**Pins:**
- AGND [pin 7]
- C1 [pin 10]
- C2 [pin 9]
- CE [pin 14]
- DGND [pin 1]
- EP [pin 15]
- MENB [pin 2]
- NC [pin 5]
- RE [pin 13]
- SCL [pin 3]
- SDA [pin 4]
- VDD [pin 6]
- VOUT [pin 8]
- VREF [pin 11]
- WE [pin 12]

### U5 — [ADS7866](https://flux.ai/kicad-part-library/ads7866~1g.md)

- Package or Case Code: TSOT\-23\-6
- Datasheet URL: http://www\.ti\.com/lit/ds/symlink/ads7866\.pdf
- Role Details: Substitute for ADC161S626; verify resolution/pinout before fabrication
- Manufacturer Name: Texas Instruments Inc\.
- Manufacturer Part Number: ADS7866

**Pins:**
- \~\{CS\} [pin 6]
- AIN [pin 3]
- GND [pin 2]
- SCLK [pin 4]
- SDO [pin 5]
- VDD [pin 1]

### U6 — [ADS7866](https://flux.ai/kicad-part-library/ads7866~1g.md)

- Package or Case Code: TSOT\-23\-6
- Datasheet URL: http://www\.ti\.com/lit/ds/symlink/ads7866\.pdf
- Role Details: Substitute for ADC161S626; verify resolution/pinout before fabrication
- Manufacturer Name: Texas Instruments Inc\.
- Manufacturer Part Number: ADS7866

**Pins:**
- \~\{CS\} [pin 6]
- AIN [pin 3]
- GND [pin 2]
- SCLK [pin 4]
- SDO [pin 5]
- VDD [pin 1]

### U7 — [ADS7866](https://flux.ai/kicad-part-library/ads7866~1g.md)

- Role Details: Substitute for ADC161S626; verify resolution/pinout before fabrication
- Package or Case Code: TSOT\-23\-6
- Datasheet URL: http://www\.ti\.com/lit/ds/symlink/ads7866\.pdf
- Manufacturer Name: Texas Instruments Inc\.
- Manufacturer Part Number: ADS7866

**Pins:**
- \~\{CS\} [pin 6]
- AIN [pin 3]
- GND [pin 2]
- SCLK [pin 4]
- SDO [pin 5]
- VDD [pin 1]

### U8 — [ADS7866](https://flux.ai/kicad-part-library/ads7866~1g.md)

- Package or Case Code: TSOT\-23\-6
- Datasheet URL: http://www\.ti\.com/lit/ds/symlink/ads7866\.pdf
- Role Details: Substitute for ADC161S626; verify resolution/pinout before fabrication
- Manufacturer Name: Texas Instruments Inc\.
- Manufacturer Part Number: ADS7866

**Pins:**
- \~\{CS\} [pin 6]
- AIN [pin 3]
- GND [pin 2]
- SCLK [pin 4]
- SDO [pin 5]
- VDD [pin 1]

### U9 — [LM4125AIM5\-2\.5](https://flux.ai/kicad-part-library/lm4125aim5-2p5~ebo.md)

- Package or Case Code: SOT\-23\-5
- Manufacturer Name: Texas Instruments Inc\.
- Datasheet URL: http://www\.ti\.com/lit/ds/symlink/lm4125\.pdf
- Manufacturer Part Number: LM4125AIM5\-2\.5

**Pins:**
- GND [pin 2]
- NC [pin 1]
- NC [pin 3]
- Vin [pin 4]
- Vout [pin 5]

*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/ximena123131/4\-channel\-gas\-sensor\-afe\~0g](https://flux.ai/ximena123131/4-channel-gas-sensor-afe~0g).*

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*Generated from [https://flux\.ai/ximena123131/4\-channel\-gas\-sensor\-afe\~0g](https://flux.ai/ximena123131/4-channel-gas-sensor-afe~0g)*