# UK Smart Wall Switch Back Board
## Description
UK Smart Wall Switch Back Board: 802.3af PoE-powered 65x65mm relay and energy-monitoring back board with RJ45, isolated 5V/3.3V rails, W5500 Ethernet, BL0942 metering, touch ICs, and 12-pin pogo interface.
## Project Details
- **Owner:** leisgordon
- **Created:** 5/15/2026
- **Last Updated:** 6/2/2026
- **Visibility:** Public
## Key Components
### BR1 — [HD01-T](https://www.flux.ai/adrian95/hd01-t.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.diodes.com/datasheet/download/HD01.pdf
- Role Details: 100V 1A bridge rectifier for PoE input pair rectification
- Mount: Surface Mount
- Manufacturer Name: Diodes
- Package or Case Code: 4-SMD
- Manufacturer Part Number: HD01-T
- Part Type: Diodes
- Role: Rectification
**Pins:**
- - [pin 3]
- + [pin 1]
- ~_1 [pin 2]
- ~_2 [pin 4]
### BR2 — [HD01-T](https://www.flux.ai/adrian95/hd01-t.md)
- Mount: Surface Mount
- Datasheet URL: https://www.diodes.com/datasheet/download/HD01.pdf
- Role Details: 100V 1A bridge rectifier for PoE input pair rectification
- Role: Rectification
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Part Number: HD01-T
- Package or Case Code: 4-SMD
- Part Type: Diodes
- Manufacturer Name: Diodes
**Pins:**
- - [pin 3]
- + [pin 1]
- ~_1 [pin 2]
- ~_2 [pin 4]
### D1 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md)
- Part Type: Diode
- Manufacturer Part Number: 1N4007RLG
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf
- Manufacturer Name: onsemi
- Role Details: Coil suppression diode for relay driver
- Role: Flyback Diode
**Pins:**
- anode [pin 2]
- cathode [pin 1]
### D2 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: onsemi
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf
- Role Details: Coil suppression diode for relay driver
- Part Type: Diode
- Manufacturer Part Number: 1N4007RLG
- Role: Flyback Diode
**Pins:**
- anode [pin 2]
- cathode [pin 1]
### D3 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md)
- Manufacturer Part Number: 1N4007RLG
- Part Type: Diode
- Role: Flyback Diode
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf
- Role Details: Coil suppression diode for relay driver
- Manufacturer Name: onsemi
**Pins:**
- anode [pin 2]
- cathode [pin 1]
### D4 — [SMAJ58A](https://www.flux.ai/lcsc/smaj58a~676s.md)
- Product Info Url: https://lcsc.com/product-detail/TVS_Shikues-SMAJ58A_C499822.html
- LCSC Part Number: C499822
- Role Details: 58V TVS across rectified PoE input as TPS23751 recommended input protection
- Manufacturer Part Number: SMAJ58A
- Manufacturer Name: SHIKUES(时科)
- Role: Protection
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Shikues-SMAJ58A_C499822.pdf
- Part Type: TVS
- JLCPCB Part Class: Extended Part
- Package or Case Code: SMA_L4.4-W2.6-LS5.0-R-RD
**Pins:**
- A [pin 1]
- K [pin 2]
### D5 — [SSC54-E3/57T](https://www.flux.ai/adrian95/ssc54-e357t~hzn.md)
- Manufacturer Name: Vishay General Semiconductor - Diodes Division
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Part Number: SSC54-E3/57T
- Role: Rectification
- Datasheet URL: https://www.vishay.com/docs/88885/ssc53l.pdf
- Part Type: Diode
- Role Details: 40V 5A Schottky rectifier for 5V 2A flyback output
**Pins:**
- A [pin 2]
- K [pin 1]
### J1 — [HR911105A](https://www.flux.ai/jecstronic/hr911105a~ae9.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Part Number: HR911105A
- Part Type: Connector
- Role: RJ45 MagJack
- Datasheet URL: https://datasheet.lcsc.com/lcsc/1811141815_HANRUN-Zhongshan-HanRun-Elec-HR911105A_C12074.pdf
- Manufacturer Name: HANRUN
- Role Details: Ethernet connector with integrated magnetics and LEDs for PoE input and W5500 PHY connection
**Pins:**
- ~ [pin 2]
- ~ [pin 6]
- ~ [pin 5]
- ~ [pin 11]
- ~ [pin 12]
- ~ [pin 8]
- ~ [pin 1]
- ~ [pin 4]
- ~ [pin 9]
- ~ [pin 3]
- ~ [pin 10]
- SHIELD [pin 15]
- SHIELD [pin 16]
### J10 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Voltage Rating: 12V
- Part Type: Connector
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Manufacturer Part Number: CPG-45-TH-TR
- Operating Temperature: -40 85 °C
- Connector Type: Board to Board Connectors
- Role: Pogo Contact
- Current Rating: 1A
**Pins:**
- 1 [pin 1]
### J11 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Part Type: Connector
- Voltage Rating: 12V
- Role: Pogo Contact
- Operating Temperature: -40 85 °C
- Manufacturer Part Number: CPG-45-TH-TR
- Connector Type: Board to Board Connectors
- Current Rating: 1A
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
**Pins:**
- 1 [pin 1]
### J12 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Voltage Rating: 12V
- Part Type: Connector
- Connector Type: Board to Board Connectors
- Current Rating: 1A
- Manufacturer Part Number: CPG-45-TH-TR
- Role: Pogo Contact
- Operating Temperature: -40 85 °C
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
**Pins:**
- 1 [pin 1]
### J13 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Current Rating: 1A
- Connector Type: Board to Board Connectors
- Manufacturer Part Number: CPG-45-TH-TR
- Operating Temperature: -40 85 °C
- Part Type: Connector
- Role: Pogo Contact
- Voltage Rating: 12V
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
**Pins:**
- 1 [pin 1]
### J14 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Part Type: Connector
- Voltage Rating: 12V
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Role: Pogo Contact
- Manufacturer Part Number: CPG-45-TH-TR
- Operating Temperature: -40 85 °C
- Current Rating: 1A
- Connector Type: Board to Board Connectors
**Pins:**
- 1 [pin 1]
### J15 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Voltage Rating: 12V
- Part Type: Connector
- Operating Temperature: -40 85 °C
- Manufacturer Part Number: CPG-45-TH-TR
- Current Rating: 1A
- Connector Type: Board to Board Connectors
- Role: Pogo Contact
**Pins:**
- 1 [pin 1]
### J2 — [691412320003](https://www.flux.ai/adrian95/691412320003.md)
- Manufacturer Name: Würth Elektronik
- Current Rating: 4A
- Role Details: 3-position 3.5mm pluggable terminal block for one mains lighting circuit; closest Flux library substitute for Phoenix Contact 1984028 PT 1,5/3-PVH-3,5
- Mount: Through Hole
- Part Type: Connector
- Role: Mains Screw Terminal
- Datasheet URL: https://www.we-online.com/components/products/datasheet/691412320003.pdf
- Connector Positions: 3
- Voltage Rating: 300V
- Substitute Manufacturer Part Number: Phoenix Contact 1984028 / PT 1,5/3-PVH-3,5 requested; exact Flux part unavailable
- Connector Pitch: 3.81mm
- Manufacturer Part Number: 691412320003
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
### J3 — [691412320003](https://www.flux.ai/adrian95/691412320003.md)
- Connector Pitch: 3.81mm
- Substitute Manufacturer Part Number: Phoenix Contact 1984028 / PT 1,5/3-PVH-3,5 requested; exact Flux part unavailable
- Manufacturer Name: Würth Elektronik
- Part Type: Connector
- Role Details: 3-position 3.5mm pluggable terminal block for one mains lighting circuit; closest Flux library substitute for Phoenix Contact 1984028 PT 1,5/3-PVH-3,5
- Mount: Through Hole
- Connector Positions: 3
- Datasheet URL: https://www.we-online.com/components/products/datasheet/691412320003.pdf
- Role: Mains Screw Terminal
- Voltage Rating: 300V
- Current Rating: 4A
- Manufacturer Part Number: 691412320003
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
### J4 — [691412320003](https://www.flux.ai/adrian95/691412320003.md)
- Current Rating: 4A
- Manufacturer Name: Würth Elektronik
- Part Type: Connector
- Role: Mains Screw Terminal
- Mount: Through Hole
- Connector Pitch: 3.81mm
- Datasheet URL: https://www.we-online.com/components/products/datasheet/691412320003.pdf
- Substitute Manufacturer Part Number: Phoenix Contact 1984028 / PT 1,5/3-PVH-3,5 requested; exact Flux part unavailable
- Role Details: 3-position 3.5mm pluggable terminal block for one mains lighting circuit; closest Flux library substitute for Phoenix Contact 1984028 PT 1,5/3-PVH-3,5
- Connector Positions: 3
- Manufacturer Part Number: 691412320003
- Voltage Rating: 300V
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
### J5 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Manufacturer Part Number: CPG-45-TH-TR
- Operating Temperature: -40 85 °C
- Current Rating: 1A
- Connector Type: Board to Board Connectors
- Part Type: Connector
- Role: Pogo Contact
- Voltage Rating: 12V
**Pins:**
- 1 [pin 1]
### J6 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Operating Temperature: -40 85 °C
- Manufacturer Part Number: CPG-45-TH-TR
- Current Rating: 1A
- Connector Type: Board to Board Connectors
- Role: Pogo Contact
- Voltage Rating: 12V
- Part Type: Connector
**Pins:**
- 1 [pin 1]
### J7 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Part Type: Connector
- Voltage Rating: 12V
- Manufacturer Part Number: CPG-45-TH-TR
- Operating Temperature: -40 85 °C
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Current Rating: 1A
- Connector Type: Board to Board Connectors
- Role: Pogo Contact
**Pins:**
- 1 [pin 1]
### J8 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Operating Temperature: -40 85 °C
- Manufacturer Part Number: CPG-45-TH-TR
- Connector Type: Board to Board Connectors
- Current Rating: 1A
- Role: Pogo Contact
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Voltage Rating: 12V
- Part Type: Connector
**Pins:**
- 1 [pin 1]
### J9 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Voltage Rating: 12V
- Role: Pogo Contact
- Part Type: Connector
- Current Rating: 1A
- Connector Type: Board to Board Connectors
- Manufacturer Part Number: CPG-45-TH-TR
- Operating Temperature: -40 85 °C
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
**Pins:**
- 1 [pin 1]
### K1 — [SRD-05VDC-SL-C](https://www.flux.ai/vasy_skral/srd-05vdc-sl-c~go1.md)
- Role Details: 5V SPDT relay for one lighting circuit
- Manufacturer Part Number: SRD-05VDC-SL-C
- Manufacturer Name: Ningbo Songle Relay
- Part Type: Relay
- Datasheet URL: https://www.circuitbasics.com/wp-content/uploads/2015/11/SRD-05VDC-SL-C-Datasheet.pdf
- Role: Mains Relay
**Pins:**
- A1 [pin A1]
- A2 [pin A2]
- COM [pin COM]
- NC [pin NC]
- NO [pin NO]
### K2 — [SRD-05VDC-SL-C](https://www.flux.ai/vasy_skral/srd-05vdc-sl-c~go1.md)
- Manufacturer Part Number: SRD-05VDC-SL-C
- Role Details: 5V SPDT relay for one lighting circuit
- Manufacturer Name: Ningbo Songle Relay
- Role: Mains Relay
- Datasheet URL: https://www.circuitbasics.com/wp-content/uploads/2015/11/SRD-05VDC-SL-C-Datasheet.pdf
- Part Type: Relay
**Pins:**
- A1 [pin A1]
- A2 [pin A2]
- COM [pin COM]
- NC [pin NC]
- NO [pin NO]
### K3 — [SRD-05VDC-SL-C](https://www.flux.ai/vasy_skral/srd-05vdc-sl-c~go1.md)
- Manufacturer Part Number: SRD-05VDC-SL-C
- Role: Mains Relay
- Part Type: Relay
- Datasheet URL: https://www.circuitbasics.com/wp-content/uploads/2015/11/SRD-05VDC-SL-C-Datasheet.pdf
- Role Details: 5V SPDT relay for one lighting circuit
- Manufacturer Name: Ningbo Songle Relay
**Pins:**
- A1 [pin A1]
- A2 [pin A2]
- COM [pin COM]
- NC [pin NC]
- NO [pin NO]
### P1 — [CPG-45-TH-TR](https://www.flux.ai/f-franzin/cpg-45-th-tr~ed.md)
- Part Type: Connector
- Role Details: One spring-loaded contact in the 12-position front-board pogo array; 12V 1A rating
- Voltage Rating: 12V
- Manufacturer Part Number: CPG-45-TH-TR
- Operating Temperature: -40 85 °C
- Role: Pogo Contact
- Current Rating: 1A
- Connector Type: Board to Board Connectors
**Pins:**
- 1 [pin 1]
### Q1 — [PC817X2NSZ9F](https://www.flux.ai/adrian95/pc817x2nsz9f-8aiu3~i8d.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Role Details: Relay-control isolation channel
- Manufacturer Part Number: PC817X2NSZ9F
- Role: Optocoupler
- Part Type: Isolator
- Manufacturer Name: SHARP/Socle Technology
- Datasheet URL: http://www.socle-tech.com/doc/IC%20Channel%20Product/Optoelectronic%20Components/Photocoupler/PC817X_NSZ9FSeries_SPEC.pdf
**Pins:**
- ANODE [pin 1]
- CATHODE [pin 2]
- COLLECTOR [pin 4]
- EMITTER [pin 3]
### Q2 — [PC817X2NSZ9F](https://www.flux.ai/adrian95/pc817x2nsz9f-8aiu3~i8d.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Optocoupler
- Manufacturer Part Number: PC817X2NSZ9F
- Part Type: Isolator
- Role Details: Relay-control isolation channel
- Datasheet URL: http://www.socle-tech.com/doc/IC%20Channel%20Product/Optoelectronic%20Components/Photocoupler/PC817X_NSZ9FSeries_SPEC.pdf
- Manufacturer Name: SHARP/Socle Technology
**Pins:**
- ANODE [pin 1]
- CATHODE [pin 2]
- COLLECTOR [pin 4]
- EMITTER [pin 3]
### Q3 — [BC33740TA](https://www.flux.ai/adrian95/bc33740ta~5dt.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Relay Driver
- Manufacturer Part Number: BC33740TA
- Part Type: Transistor
- Role Details: Low-side NPN driver for 5V relay coil
- Datasheet URL: https://www.verical.com/datasheet/on-semiconductor-bjt---general-purpose-BC33740TA-4544246.pdf
- Manufacturer Name: onsemi
**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]
### Q4 — [BC33740TA](https://www.flux.ai/adrian95/bc33740ta~5dt.md)
- Manufacturer Part Number: BC33740TA
- Role: Relay Driver
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: onsemi
- Role Details: Low-side NPN driver for 5V relay coil
- Part Type: Transistor
- Datasheet URL: https://www.verical.com/datasheet/on-semiconductor-bjt---general-purpose-BC33740TA-4544246.pdf
**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]
### Q5 — [BC33740TA](https://www.flux.ai/adrian95/bc33740ta~5dt.md)
- Part Type: Transistor
- Datasheet URL: https://www.verical.com/datasheet/on-semiconductor-bjt---general-purpose-BC33740TA-4544246.pdf
- Manufacturer Name: onsemi
- Role: Relay Driver
- License: https://creativecommons.org/licenses/by/4.0/
- Role Details: Low-side NPN driver for 5V relay coil
- Manufacturer Part Number: BC33740TA
**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]
### Q6 — [IRF540NSTRLPBF](https://www.flux.ai/jharwinbarrozo/irf540nstrlpbf~d5.md)
- Role Details: 100V N-channel MOSFET for primary flyback switch; verify gate charge and thermal performance
- Manufacturer Part Number: IRF540NSTRLPBF
- Datasheet URL: https://www.infineon.com/dgdl/irf540nspbf.pdf?fileId=5546d462533600a4015355e3a72819a3
- Part Type: Transistor
- Role: Switching
- Manufacturer Name: Texas Instruments Inc.
**Pins:**
- D [pin 2]
- G [pin 1]
- S [pin 3]
### T1 — [POE13P-50LD](https://www.flux.ai/jecstronic/poe13p-50ld~3v.md)
- Manufacturer Name: Coilcraft
- Role Details: 13W PoE flyback transformer, 5.0V 2.6A output; replacement for NA5730-AL to satisfy 5V 2A output requirement
- Datasheet URL: https://www.mouser.com/datasheet/2/597/poe_ep-463527.pdf
- Role: Flyback Transformer
- Manufacturer Part Number: POE13P-50LD
- Part Type: Transformer
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- 5 [pin 5]
- 6 [pin 6]
- BIAS_1 [pin 1]
- BIAS_2 [pin 2]
- PRI_1 [pin 3]
- PRI_2 [pin 4]
- SEC_1 [pin 7]
- SEC_2 [pin 8]
- SEC_3 [pin 9]
- SEC_4 [pin 10]
### U1 — [TPS23751PWPR](https://www.flux.ai/lcsc/tps23751pwpr~isno.md)
- Role Details: Primary-side PoE powered-device interface and flyback controller for isolated 5V output
- Role: PoE PD Controller
- Package or Case Code: HTSSOP-16_L5.0-W4.4-P0.65-LS6.4-BL-EP
- JLCPCB Part Class: Extended Part
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410010131_Texas-Instruments-TPS23751PWPR_C473395.pdf
- LCSC Part Number: C473395
- Manufacturer Name: TI(德州仪器)
- Product Info Url: https://lcsc.com/product-detail/Pre-ordered-Chips_Texas-Instruments-Texas-Instruments-TPS23751PWPR_C473395.html
- Manufacturer Part Number: TPS23751PWPR
**Pins:**
- APD [pin 4]
- ARTN [pin 14]
- CLS [pin 3]
- CS [pin 11]
- CTL [pin 8]
- DEN [pin 2]
- EP [pin 17]
- GATE [pin 13]
- RT [pin 5]
- RTN [pin 15]
- SRD [pin 7]
- SRT [pin 9]
- T2P [pin 6]
- VB [pin 10]
- VC [pin 12]
- VDD [pin 1]
- VSS [pin 16]
### U10 — [PC817X2NSZ9F](https://www.flux.ai/adrian95/pc817x2nsz9f-8aiu3~i8d.md)
- Role: Isolation
- Datasheet URL: http://www.socle-tech.com/doc/IC%20Channel%20Product/Optoelectronic%20Components/Photocoupler/PC817X_NSZ9FSeries_SPEC.pdf
- Manufacturer Name: SHARP/Socle Technology
- Part Type: Isolator
- Manufacturer Part Number: PC817X2NSZ9F
- Role Details: Feedback optocoupler crossing isolation boundary for flyback control loop
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- ANODE [pin 1]
- CATHODE [pin 2]
- COLLECTOR [pin 4]
- EMITTER [pin 3]
### U2 — [AMS1117-3.3](https://www.flux.ai/vasy_skral/ams1117-33~34.md)
- Symbol Style: Parametric
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Integrated Circuit
- Manufacturer Name: AMS
- Datasheet URL: http://www.advanced-monolithic.com/pdf/ds1117.pdf
- Role Details: 5V-to-3.3V post regulator; requires input/output capacitors and thermal check
- Role: 3.3V LDO
- Manufacturer Part Number: AMS1117-3.3
**Pins:**
- GND [pin 1]
- TAB(VOUT) [pin 4]
- VIN [pin 3]
- VOUT [pin 2]
### U3 — [W5500](https://www.flux.ai/vasy_skral/w5500~9ux.md)
- Role: Ethernet Controller
- Role Details: 10/100 Ethernet controller; SPI interface routed to 12-contact pogo interface
- Manufacturer Part Number: W5500
- Symbol Style: parametric-v1
- Manufacturer Name: WIZnet
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Integrated Circuit
- Datasheet URL: https://docs.wiznet.io/img/products/w5500/w5500_ds_v109e.pdf
**Pins:**
- ~INT [pin 36]
- ~RST [pin 37]
- ~SCS [pin 32]
- 1V2O [pin 22]
- ACTLED [pin 27]
- AGND [pin 3]
- AGND [pin 16]
- AGND [pin 14]
- AGND [pin 48]
- AGND [pin 9]
- AGND [pin 19]
- AVDD [pin 21]
- AVDD [pin 15]
- AVDD [pin 8]
- AVDD [pin 11]
- AVDD [pin 4]
- AVDD [pin 17]
- DNC [pin 7]
- DUPLED [pin 26]
- EXRES1 [pin 10]
- GND [pin 29]
- LINKLED [pin 25]
- MISO [pin 34]
- MOSI [pin 35]
- NC [pin 46]
- NC [pin 12]
- NC [pin 47]
- NC [pin 13]
- PMODE0 [pin 45]
- PMODE1 [pin 44]
- PMODE2 [pin 43]
- RSVD [pin 23]
- RSVD [pin 42]
- RSVD [pin 38]
- RSVD [pin 39]
- RSVD [pin 40]
- RSVD [pin 41]
- RXN [pin 5]
- RXP [pin 6]
- SCLK [pin 33]
- SPDLED [pin 24]
- TOCAP [pin 20]
- TXN [pin 1]
- TXP [pin 2]
- VBG [pin 18]
- VDD [pin 28]
- XI/CLKIN [pin 30]
- XO [pin 31]
### U4 — [BL0942](https://www.flux.ai/lcsc/bl0942~6cfm.md)
- Manufacturer Name: BL(上海贝岭)
- Role: Energy Monitor
- Manufacturer Part Number: BL0942
- Part Type: PMIC - Current Regulation
- LCSC Part Number: C2837510
- Role Details: Mains live-line metering IC for voltage/current/power monitoring
- JLCPCB Part Class: Extended Part
- Package or Case Code: SSOP-10_L4.9-W3.9-P1.00-LS6.0-BL
**Pins:**
- CF1 [pin 6]
- GND [pin 5]
- IN [pin 3]
- IP [pin 2]
- RX/SDI [pin 9]
- SCLK_BPS [pin 8]
- SEL [pin 7]
- TX/SDO [pin 10]
- VDD [pin 1]
- VP [pin 4]
### U5 — [TTP223-BA6](https://www.flux.ai/lcsc/ttp223-ba6~g6w0.md)
- Part Type: Touch Sensors
- LCSC Part Number: C2757936
- Datasheet URL: https://www.lcsc.com/datasheet/C2757936.pdf?spm=wm.sxq.inf.ggs___wm.fly.bg.2.xh&lcsc_vid=QlUIU1dSRgJcA1FQQVUMBgdeElQIVldRQ1daVQdeQAcxVlNeR1JcUVdQRVJZUDsOAxUeFF5JWBYZEEoKFBINSQcJGk4%3D
- JLCPCB Part Class: Extended Part
- Role: Capacitive Touch Sensor
- Role Details: One touch-key detector IC per lighting channel
- Manufacturer Name: TONTEK(通泰)
- Symbol Style: parametric-v1
- Manufacturer Part Number: TTP223-BA6
- Package or Case Code: SOT-23-6_L2.9-W1.6-P0.95-LS2.8-BR
**Pins:**
- AHLB [pin 4]
- I [pin 3]
- Q [pin 1]
- TOG [pin 6]
- VDD [pin 5]
- VSS [pin 2]
### U6 — [TTP223-BA6](https://www.flux.ai/lcsc/ttp223-ba6~g6w0.md)
- Datasheet URL: https://www.lcsc.com/datasheet/C2757936.pdf?spm=wm.sxq.inf.ggs___wm.fly.bg.2.xh&lcsc_vid=QlUIU1dSRgJcA1FQQVUMBgdeElQIVldRQ1daVQdeQAcxVlNeR1JcUVdQRVJZUDsOAxUeFF5JWBYZEEoKFBINSQcJGk4%3D
- JLCPCB Part Class: Extended Part
- LCSC Part Number: C2757936
- Part Type: Touch Sensors
- Package or Case Code: SOT-23-6_L2.9-W1.6-P0.95-LS2.8-BR
- Manufacturer Part Number: TTP223-BA6
- Role Details: One touch-key detector IC per lighting channel
- Manufacturer Name: TONTEK(通泰)
- Symbol Style: parametric-v1
- Role: Capacitive Touch Sensor
**Pins:**
- AHLB [pin 4]
- I [pin 3]
- Q [pin 1]
- TOG [pin 6]
- VDD [pin 5]
- VSS [pin 2]
### U7 — [TTP223-BA6](https://www.flux.ai/lcsc/ttp223-ba6~g6w0.md)
- Role: Capacitive Touch Sensor
- Manufacturer Part Number: TTP223-BA6
- Package or Case Code: SOT-23-6_L2.9-W1.6-P0.95-LS2.8-BR
- Manufacturer Name: TONTEK(通泰)
- Symbol Style: parametric-v1
- Datasheet URL: https://www.lcsc.com/datasheet/C2757936.pdf?spm=wm.sxq.inf.ggs___wm.fly.bg.2.xh&lcsc_vid=QlUIU1dSRgJcA1FQQVUMBgdeElQIVldRQ1daVQdeQAcxVlNeR1JcUVdQRVJZUDsOAxUeFF5JWBYZEEoKFBINSQcJGk4%3D
- JLCPCB Part Class: Extended Part
- Role Details: One touch-key detector IC per lighting channel
- Part Type: Touch Sensors
- LCSC Part Number: C2757936
**Pins:**
- AHLB [pin 4]
- I [pin 3]
- Q [pin 1]
- TOG [pin 6]
- VDD [pin 5]
- VSS [pin 2]
### U8 — [PC817X2NSZ9F](https://www.flux.ai/adrian95/pc817x2nsz9f-8aiu3~i8d.md)
- Part Type: Isolator
- Datasheet URL: http://www.socle-tech.com/doc/IC%20Channel%20Product/Optoelectronic%20Components/Photocoupler/PC817X_NSZ9FSeries_SPEC.pdf
- Manufacturer Name: SHARP/Socle Technology
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Optocoupler
- Role Details: Relay-control isolation channel
- Manufacturer Part Number: PC817X2NSZ9F
**Pins:**
- ANODE [pin 1]
- CATHODE [pin 2]
- COLLECTOR [pin 4]
- EMITTER [pin 3]
### U9 — [TL431AIL3T](https://www.flux.ai/adrian95/tl431ail3t~xnq.md)
- Role: Voltage Reference
- Role Details: TL431 feedback reference for 5V flyback output regulation
- Manufacturer Name: STMicroelectronics
- Datasheet URL: https://www.st.com/content/ccc/resource/technical/document/datasheet/2d/27/af/41/03/e2/44/8e/CD00000986.pdf/files/CD00000986.pdf/jcr:content/translations/en.CD00000986.pdf
- Part Type: Integrated Circuit
- Manufacturer Part Number: TL431AIL3T
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- A [pin 3]
- K [pin 1]
- REF [pin 2]
### Y1 — [NX3225GA-25MHZ-STD-CRG-2](https://www.flux.ai/lcsc/nx3225ga-25mhz-std-crg-2~jt15.md)
- LCSC Part Number: C438901
- Manufacturer Part Number: NX3225GA-25MHZ-STD-CRG-2
- Role Details: 25MHz crystal for W5500 XI/XO pins
- Manufacturer Name: NDK
- Package or Case Code: OSC-SMD_4P-L3.2-W2.5-BL
- JLCPCB Part Class: Extended Part
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_NDK-NX3225GA-25MHZ-STD-CRG-2_C438901.pdf
- Role: Crystal
- Product Info Url: https://lcsc.com/product-detail/SMD-Crystal-Resonators_NDK-NX3225GA-STD-CRG-2-25MHZ_C438901.html
- Part Type: Crystals
**Pins:**
- 1 [pin 1]
- 3 [pin 3]
- GND [pin 4]
- GND [pin 2]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/leisgordon/uk-smart-wall-switch-back-board~xz](https://www.flux.ai/leisgordon/uk-smart-wall-switch-back-board~xz).*
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*Generated from [https://www.flux.ai/leisgordon/uk-smart-wall-switch-back-board~xz](https://www.flux.ai/leisgordon/uk-smart-wall-switch-back-board~xz)*