# EcoCore Refboard
## Description
EcoCore ESP32 Reference Board – Final Net Mapping, Protection Ratings, 4-Layer PCB Prep, and Integrated USB-C Programming Interface with USB-UART Bridge, CC Pull-Downs, Low-Capacitance ESD Protection, and Isolated USB 5V / 5V Actuator / 12V Rails (with Verified DRC/ERC Status and Pre-Production Layout Checklist)
## Project Details
- **Owner:** terratronix
- **Created:** 12/25/2025
- **Last Updated:** 12/25/2025
- **Visibility:** Public
- **System Architecture:** ```mermaid
flowchart TD
MCU["ESP32 MCU Domain"]
PWR["Power/Protection Domain"]
REL["Relay Control Domain"]
PWM["PWM I/O Headers"]
DHT["DHT22 Connectors"]
I2C["I2C Expansion Header"]
DBG["Programming/Test Pad Domain"]
LED["Status LED Domain"]
USB["USB Interface Domain"]
PWR --> MCU
MCU --> REL
MCU --> PWM
MCU --> DHT
MCU --> I2C
MCU --> DBG
MCU --> LED
MCU --> USB
```
- **Trace Widths:** 12V = 3 mm, 5V = 1 mm, 3V3 = 0.8 mm
- **Trace Width 5V:** 1mm
- **USB-C Placement:** Near ESP32, away from relay/12V zone
- **Net Class: Low Speed:** EN, IO0, PWM1, PWM2, CC1, CC2, DHT1_DATA, DHT2_DATA
- **Zone A (Logic):** Contains U1, J8, U5, J6, J7, D7, R15, R16, USB test points TP_DP/TP_DN/TP_CC1/TP_CC2, TP_3V3, TP_5V, TP_GND, D4–D6, and associated passives
- **Trace Width 3V3:** 0.8mm
- **Board Dimensions:** 40.0 mm × 25.0 mm
- **Net Class: Medium Speed:** TX0, RX0
- **Silkscreen Intent:** Clear outlines and labels for USB-C receptacle, CC, D+/D– test pads
- **Mechanical Features:** Four non-plated 3.0 mm holes (TP_DP, TP_DN, TP_CC1, TP_CC2 groups) used as combined mounting and USB probe access
- **Stackup:** Standard 4 Layer: Top (signal), Layer 2 (ground plane), Layer 3 (power pours), Bottom (signal)
- **Mounting Approach:** USB-C and BOOT/RESET header near ESP32, keep clearance from relay/12V zone; use existing 3.0 mm non-plated holes (TP_DP/TP_DN/TP_CC1/TP_CC2) as mechanical and probe access features
- **Mounting Holes:** Four non-plated 3.0 mm holes (TP_DP, TP_DN, TP_CC1, TP_CC2) used as mechanical mounting and USB probe access features
- **Zone B (Power/Relays):** Contains F1, D1–D3, D8–D9, U2, U3, U4, J1–J3, J4–J5, TP_12V, bulk/decoupling capacitors C1–C4, and relay status LEDs and resistors
- **Net Class: High Speed:** D+, D-
- **Trace Width 12V:** 3mm
- **Net Class: Ground:** GND
## Key Components
### D1 — [1N4001-TP](https://www.flux.ai/adrian95/1n4001-tp~3k.md)
- Part Type: Diode
- Manufacturer Name: Micro Commercial Co
- Manufacturer Part Number: 1N4001-TP
- Package: DO-41
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Protection
- Role Details: Reverse polarity protection for 12V input
- Datasheet URL: https://www.mccsemi.com/pdf/Products/1N4001~1N4007(DO-41).pdf
**Pins:**
- A [pin 2]
- K [pin 1]
### D2 — [SS14](https://www.flux.ai/jecstronic/ss14~ri4.md)
- Manufacturer Part Number: SS14
- Part Type: Diode
- Role: Protection
- Role Details: Schottky diode for input protection and reverse blocking
- Datasheet URL: https://datasheet.lcsc.com/lcsc/1912111437_Slkor-SLKORMICRO-Elec--SS14_C444721.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Package: SMA
- Manufacturer Name: Slkor(SLKORMICRO Elec.)
**Pins:**
- Anode [pin A]
- Cathode [pin C]
### D3 — [SMBJ14A](https://www.flux.ai/lcsc/smbj14a~u7fo.md)
- Package or Case Code: SMB_L4.5-W3.7-LS5.4-RD
- Manufacturer Name: Liown(里阳半导体)
- LCSC Part Number: C2989893
- Package: SMB_L4.5-W3.7-LS5.4-RD
- Role Details: TVS diode for transient voltage suppression on 12V input
- Role: Protection
- Manufacturer Part Number: SMBJ14A
- JLCPCB Part Class: Extended Part
- Part Type: TVS
**Pins:**
- A [pin 2]
- C [pin 1]
### D4 — [SMLP14ECNWT86](https://www.flux.ai/moshtey/smlp14ecnwt86~ov.md)
- Mount: Surface Mount
- Package: LEDM1608X80
- Manufacturer Part Number: SMLP14ECNWT86
- Package or Case Code: D_0603_1608Metric
- Part Type: LED
- Role Details: Rail indicator for 12V rail
- Diode Type: LED
- Role: LED
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D5 — [SMLP14ECNWT86](https://www.flux.ai/moshtey/smlp14ecnwt86~ov.md)
- Role Details: Rail indicator for 5V rail
- Package or Case Code: D_0603_1608Metric
- Package: LEDM1608X80
- Mount: Surface Mount
- Manufacturer Part Number: SMLP14ECNWT86
- Role: LED
- Diode Type: LED
- Part Type: LED
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D6 — [SMLP14ECNWT86](https://www.flux.ai/moshtey/smlp14ecnwt86~ov.md)
- Manufacturer Part Number: SMLP14ECNWT86
- Mount: Surface Mount
- Package: LEDM1608X80
- Diode Type: LED
- Role: LED
- Role Details: Rail indicator for 3.3V rail
- Package or Case Code: D_0603_1608Metric
- Part Type: LED
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D7 — [USBLC6-2P6](https://www.flux.ai/kicad-part-library/usblc6-2p6~djt.md)
- Role: Protection
- Datasheet URL: https://www.st.com/resource/en/datasheet/usblc6-2.pdf
- Manufacturer Name: Texas Instruments Inc.
- Role Details: ESD protection for USB D+ and D− lines
- Manufacturer Part Number: USBLC6-2P6
- Package: SOT-666
- Package or Case Code: SOT-666
**Pins:**
- GND [pin 2]
- I/O1 [pin 1]
- I/O1 [pin 6]
- I/O2 [pin 3]
- I/O2 [pin 4]
- VBUS [pin 5]
### D7 — [USBLC6-2P6](https://www.flux.ai/kicad-part-library/usblc6-2p6~djt.md)
- Package or Case Code: SOT-666
- Role: Protection
- Manufacturer Part Number: USBLC6-2P6
- Role Details: Low-capacitance ESD protection for USB D+ and D− lines
- Datasheet URL: https://www.st.com/resource/en/datasheet/usblc6-2.pdf
- Manufacturer Name: Texas Instruments Inc.
**Pins:**
- GND [pin 2]
- I/O1 [pin 1]
- I/O1 [pin 6]
- I/O2 [pin 3]
- I/O2 [pin 4]
- VBUS [pin 5]
### D8 — [SS14](https://www.flux.ai/jecstronic/ss14~ri4.md)
- Manufacturer Part Number: SS14
- Role: Protection
- Role Details: Schottky OR-ing diode from USB 5V net to 3.3V LDO VIN
- Part Type: Diode
- License: https://creativecommons.org/licenses/by/4.0/
- Package: SMA
- Datasheet URL: https://datasheet.lcsc.com/lcsc/1912111437_Slkor-SLKORMICRO-Elec--SS14_C444721.pdf
- Manufacturer Name: Slkor(SLKORMICRO Elec.)
**Pins:**
- Anode [pin A]
- Cathode [pin C]
### D8, D9 — [SS14](https://www.flux.ai/jecstronic/ss14~ri4.md)
- Manufacturer Part Number: SS14
- Role Details: Schottky OR-ing diode for USB and primary 5V isolation
- Part Type: Diode
- Role: Protection
- Datasheet URL: https://datasheet.lcsc.com/lcsc/1912111437_Slkor-SLKORMICRO-Elec--SS14_C444721.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Package: SMA
- Manufacturer Name: Slkor(SLKORMICRO Elec.)
**Pins:**
- Anode [pin A]
- Cathode [pin C]
### D8, D9 — [SS14](https://www.flux.ai/jecstronic/ss14~ri4.md)
- Part Type: Diode
- Package: SMA
- Manufacturer Part Number: SS14
- Role Details: Schottky OR-ing diode for USB and primary 5V isolation
- Manufacturer Name: Slkor(SLKORMICRO Elec.)
- Role: Protection
- Datasheet URL: https://datasheet.lcsc.com/lcsc/1912111437_Slkor-SLKORMICRO-Elec--SS14_C444721.pdf
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- Anode [pin A]
- Cathode [pin C]
### D9 — [SS14](https://www.flux.ai/jecstronic/ss14~ri4.md)
- Part Type: Diode
- Manufacturer Part Number: SS14
- Role Details: Schottky OR-ing diode from primary 5V net to 3.3V LDO VIN
- Package: SMA
- Role: Protection
- Datasheet URL: https://datasheet.lcsc.com/lcsc/1912111437_Slkor-SLKORMICRO-Elec--SS14_C444721.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: Slkor(SLKORMICRO Elec.)
**Pins:**
- Anode [pin A]
- Cathode [pin C]
### F1 — [0ZCF0200AF2C](https://www.flux.ai/adrian95/0zcf0200af2c~eal.md)
- Role Details: Series fuse for 12V DC input
- Role: Protection
- Package: FUSC7451X80N
- Manufacturer Part Number: 0ZCF0200AF2C
- Manufacturer Name: BelFuse
- Part Type: Fuse
- Package or Case Code: FUSC7451X80N
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://belfuse.com/resources/datasheets/circuitprotection/ds-cp-0zcf-series.pdf
**Pins:**
- ~ [pin 2]
- ~ [pin 1]
### J2 — [0534260210](https://www.flux.ai/jecstronic/0534260210~mh7.md)
- Datasheet URL: https://www.molex.com/en-us/products/part-detail/534260210?display=pdf
- Mount: Through Hole
- Connector Type: Headers and Wire Housings
- Part Type: Connector
- Package: 534260210
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Connector
- Manufacturer Name: Molex
- Role Details: Logic-level PWM signal header
- Manufacturer Part Number: 0534260210
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### J3 — [0534260210](https://www.flux.ai/jecstronic/0534260210~mh7.md)
- Manufacturer Name: Molex
- Manufacturer Part Number: 0534260210
- Role Details: Logic-level PWM signal header
- Part Type: Connector
- License: https://creativecommons.org/licenses/by/4.0/
- Package: 534260210
- Datasheet URL: https://www.molex.com/en-us/products/part-detail/534260210?display=pdf
- Role: Connector
- Connector Type: Headers and Wire Housings
- Mount: Through Hole
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### J4 — [SM03B-GHS-TB(LF)(SN)](https://www.flux.ai/lcsc/sm03b-ghs-tblfsn~j14u.md)
- Gender: Female
- Role Details: Remote DHT22 sensor connector
- LCSC Part Number: C514175
- Connector Type: Header
- Rows: 1
- Part Type: Wire To Board / Wire To Wire Connector
- Package: SMD, 1.25mm Pitch, Right Angle
- Positions: 3
- Manufacturer Name: JST
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: SM03B-GHS-TB(LF)(SN)
- Pitch: 0.049" (1.25mm)
- Package or Case Code: CONN-TH_SM03B-GHS-TB-LF-SN
- Role: Connector
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
- 5 [pin 5]
### J5 — [SM03B-GHS-TB(LF)(SN)](https://www.flux.ai/lcsc/sm03b-ghs-tblfsn~j14u.md)
- LCSC Part Number: C514175
- Role Details: Remote DHT22 sensor connector
- Connector Type: Header
- Package: SMD, 1.25mm Pitch, Right Angle
- Gender: Female
- Pitch: 0.049" (1.25mm)
- Package or Case Code: CONN-TH_SM03B-GHS-TB-LF-SN
- Manufacturer Part Number: SM03B-GHS-TB(LF)(SN)
- Manufacturer Name: JST
- Positions: 3
- JLCPCB Part Class: Extended Part
- Part Type: Wire To Board / Wire To Wire Connector
- Rows: 1
- Role: Connector
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
- 5 [pin 5]
### J6 — [Pin Header 01x04 2.54mm Vertical i2c](https://www.flux.ai/hasanbasri93/pin-header-01x04-2p54mm-vertical-i2c~37.md)
- Connector Positions: 4
- Package or Case Code: CONN-TH
- Role Details: I2C expansion header with jumper-disable pull-ups on SDA and SCL
- Connector Pitch: 2.54mm
- Mount: Through Hole
- Package: PinHeader_1x04_P2.54mm_Vertical
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Connector
- Connector Type: Headers and Wire Housings
- Connector Rows: 1
- Part Type: Connector
**Pins:**
- 5V [pin 1]
- GND [pin 2]
- SCL [pin 4]
- SDA [pin 3]
### J7 — [Pin Header 02x03 2.54mm Vertical](https://www.flux.ai/adrian95/pin-header-02x03-254mm-vertical~z8m.md)
- Role Details: ESP32 Programming Header
- Connector Positions: 6
- Connector Type: Headers and Wire Housings
- Package or Case Code: CONN-TH
- Connector Pitch: 2.54mm
- License: https://creativecommons.org/licenses/by/4.0/
- Mount: Through Hole
- Connector Rows: 2
- Package: PinHeader_2x03_P2.54mm_Vertical
- Role: Connector
- Part Type: Connector
**Pins:**
- Pin_1 [pin 1]
- Pin_2 [pin 2]
- Pin_3 [pin 3]
- Pin_4 [pin 4]
- Pin_5 [pin 5]
- Pin_6 [pin 6]
### J8 — [Type-C-2.0-6Pin](https://www.flux.ai/jharwinbarrozo/type-c-2p0-6pin~wh.md)
- Package: Right Angle SMT USB-C
- Part Type: Connector
- Manufacturer Name: CIKI
- Manufacturer Part Number: Type-C-2.0-6Pin
- Role Details: USB-C programming port receptacle near ESP32
- Datasheet URL: https://datasheet.lcsc.com/lcsc/2204071830_CIKI-Type-C-2-0-6Pin_C2987385.pdf
- Role: Connector
**Pins:**
- CC1
- CC2
- GND
- GND__1
- SHIELD
- SHIELD__1
- SHIELD__2
- SHIELD__3
- V-BUS
- V-BUS__1
### J8 — [2024100002](https://www.flux.ai/adrian95/2024100002~atk.md)
- Role Details: USB-C programming port receptacle
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Connector
- Manufacturer Name: Molex
- Manufacturer Part Number: 2024100002
- Package: Surface Mount, Right Angle
- Role: Connector
- Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/834/202410002_Pkg_Spec.pdf
**Pins:**
- CC1 [pin A5]
- CC2 [pin B5]
- DA- [pin A7]
- DA+ [pin A6]
- DB- [pin B7]
- DB+ [pin B6]
- GND1 [pin A1]
- GND2 [pin A12]
- GND3 [pin B1]
- GND4 [pin B12]
- RX1- [pin B10]
- RX1+ [pin B11]
- RX2- [pin A10]
- RX2+ [pin A11]
- SBU1 [pin A8]
- SBU2 [pin B8]
- SHIELD1 [pin SH1]
- SHIELD2 [pin SH2]
- SHIELD3 [pin SH3]
- SHIELD4 [pin SH4]
- TX1- [pin A3]
- TX1+ [pin A2]
- TX2- [pin B3]
- TX2+ [pin B2]
- VBUS1 [pin A4]
- VBUS2 [pin A9]
- VBUS3 [pin B4]
- VBUS4 [pin B9]
### LED1 — [SML-LXFM0603SRC-TR](https://www.flux.ai/adrian95/sml-lxfm0603src-tr~r5t.md)
- Role Details: Relay status indicator
- Manufacturer Part Number: SML-LXFM0603SRC-TR
- Role: LED
- Diode Type: LED
- Manufacturer Name: Lumex Opto/Components Inc.
- Package or Case Code: D_0603_1608Metric
- Mount: Surface Mount
- Package: LEDM1608X80
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/974/SML-LXFM0603SRC-TR_Dwg_RevD_8-26-19.pdf
- Part Type: LED
**Pins:**
- A [pin 2]
- K [pin 1]
### LED2 — [SML-LXFM0603SRC-TR](https://www.flux.ai/adrian95/sml-lxfm0603src-tr~r5t.md)
- Role: LED
- Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/974/SML-LXFM0603SRC-TR_Dwg_RevD_8-26-19.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: LED
- Package or Case Code: D_0603_1608Metric
- Manufacturer Name: Lumex Opto/Components Inc.
- Diode Type: LED
- Package: LEDM1608X80
- Role Details: Relay status indicator
- Manufacturer Part Number: SML-LXFM0603SRC-TR
- Mount: Surface Mount
**Pins:**
- A [pin 2]
- K [pin 1]
### LED3 — [SML-LXFM0603SRC-TR](https://www.flux.ai/adrian95/sml-lxfm0603src-tr~r5t.md)
- Manufacturer Part Number: SML-LXFM0603SRC-TR
- Mount: Surface Mount
- Package or Case Code: D_0603_1608Metric
- Manufacturer Name: Lumex Opto/Components Inc.
- Role Details: Relay status indicator
- Package: LEDM1608X80
- Part Type: LED
- Diode Type: LED
- Role: LED
- Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/974/SML-LXFM0603SRC-TR_Dwg_RevD_8-26-19.pdf
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- A [pin 2]
- K [pin 1]
### LED4 — [SML-LXFM0603SRC-TR](https://www.flux.ai/adrian95/sml-lxfm0603src-tr~r5t.md)
- Package: LEDM1608X80
- Diode Type: LED
- Package or Case Code: D_0603_1608Metric
- Role Details: Relay status indicator
- Manufacturer Part Number: SML-LXFM0603SRC-TR
- Role: LED
- Mount: Surface Mount
- Manufacturer Name: Lumex Opto/Components Inc.
- Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/974/SML-LXFM0603SRC-TR_Dwg_RevD_8-26-19.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: LED
**Pins:**
- A [pin 2]
- K [pin 1]
### TP_12V — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Role Details: Test point for 12V rail
- Role: Test Point
**Pins:**
- P1
### TP_3V3 — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Role Details: Test point for 3.3V rail
- Role: Test Point
**Pins:**
- P1
### TP_5V — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Role: Test Point
- Role Details: Test point for 5V rail
**Pins:**
- P1
### TP_CC1 — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Package: 1.25mm SMD
- Role Details: CC1 test pad
- Role: Test Point
**Pins:**
- P1
### TP_CC2 — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Role Details: CC2 test pad
- Package: 1.25mm SMD
- Role: Test Point
**Pins:**
- P1
### TP_DN — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Role Details: USB D– test pad
- Package: 1.25mm SMD
- Role: Test Point
**Pins:**
- P1
### TP_DP — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Role Details: USB D+ test pad
- Package: 1.25mm SMD
- Role: Test Point
**Pins:**
- P1
### TP_GND — [1.25mm SMD Test Point](https://www.flux.ai/jharwinbarrozo/1p25mm-smd-test-point~b9.md)
- Role Details: Ground reference test point
- Role: Test Point
**Pins:**
- P1
### U1 — [ESP32-WROOM-32D](https://www.flux.ai/vasyl/esp32-wroom-32d~7py.md)
- Manufacturer Name: Espressif Systems
- Datasheet URL: https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32d_esp32-wroom-32u_datasheet_en.pdf
- Manufacturer Part Number: ESP32-WROOM-32D
- Role: Main MCU
- Part Type: Microcontroller
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- 3.3V [pin 2]
- AGND [pin 39]
- CLK [pin 20]
- CMD [pin 19]
- EN [pin 3]
- GND [pin 38]
- GND [pin 15]
- GND [pin 1]
- IO0 [pin 25]
- IO12 [pin 14]
- IO13 [pin 16]
- IO14 [pin 13]
- IO15 [pin 23]
- IO16 [pin 27]
- IO17 [pin 28]
- IO18 [pin 30]
- IO19 [pin 31]
- IO2 [pin 24]
- IO21 [pin 33]
- IO22 [pin 36]
- IO23 [pin 37]
- IO25 [pin 10]
- IO26 [pin 11]
- IO27 [pin 12]
- IO32 [pin 8]
- IO33 [pin 9]
- IO34 [pin 6]
- IO35 [pin 7]
- IO4 [pin 26]
- IO5 [pin 29]
- NC [pin 32]
- RXD0 [pin 34]
- SD0 [pin 21]
- SD1 [pin 22]
- SD2 [pin 17]
- SD3 [pin 18]
- TXD0 [pin 35]
- VN [pin 5]
- VP [pin 4]
### U3 — [MCP1825S-3302E/DB](https://www.flux.ai/adrian95/mcp1825s-3302edb~3re.md)
- Manufacturer Name: Microchip
- Part Type: Power Management
- Role: Power Conversion
- License: https://creativecommons.org/licenses/by/4.0/
- Package: SOT230P700X180-4N
- Datasheet URL: https://datasheet.datasheetarchive.com/originals/distributors/SFDatasheet-4/sf-00090042.pdf
- Manufacturer Part Number: MCP1825S-3302E/DB
- Package or Case Code: SOT230P700X180-4N
- Role Details: 5 V to 3.3 V LDO regulator, 500 mA output, dropout < 200 mV
**Pins:**
- GND_(TAB)_1 [pin 2]
- GND_(TAB)_2 [pin 4]
- VIN [pin 1]
- VOUT [pin 3]
### U4 — [ULN2803A](https://www.flux.ai/lcsc/uln2803a~i9jk.md)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410251531_UMW-Youtai-Semiconductor-Co---Ltd--ULN2803A_C845537.pdf
- JLCPCB Part Class: Extended Part
- Role: Relay Driver
- Package or Case Code: SOP-18_L11.4-W7.6-P1.27-LS10.6-BL
- Role Details: 4-channel Darlington transistor array for relay coil drivers with integrated flyback diodes
- Product Info Url: https://lcsc.com/product-detail/Darlington-transistor-array-driver_UMW-Youtai-Semiconductor-Co-Ltd-ULN2803A_C845537.html
- Part Type: Darlington transistor array driver
- Manufacturer Name: UMW(友台半导体)
- LCSC Part Number: C845537
- Manufacturer Part Number: ULN2803A
**Pins:**
- COM [pin 10]
- GND [pin 9]
- Input [pin 5]
- Input [pin 1]
- Input [pin 6]
- Input [pin 4]
- Input [pin 8]
- Input [pin 3]
- Input [pin 2]
- Input [pin 7]
- Output [pin 16]
- Output [pin 15]
- Output [pin 13]
- Output [pin 12]
- Output [pin 18]
- Output [pin 17]
- Output [pin 11]
- Output [pin 14]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/terratronix/ecocore-refboard~w6](https://www.flux.ai/terratronix/ecocore-refboard~w6).*
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*Generated from [https://www.flux.ai/terratronix/ecocore-refboard~w6](https://www.flux.ai/terratronix/ecocore-refboard~w6)*