# Heimdall Bypass
## Description
Compact 4-layer automotive ESP32 Bluetooth accessory with protected 12 V input, USB-C programming/power, and a strict antenna keepout for under-seat motorcycle installation.
## Project Details
- **Owner:** scorp1084
- **Created:** 8/16/2026
- **Last Updated:** 8/17/2026
- **Visibility:** Public
## Key Components
### D1 — [SMBJ33A](https://www.flux.ai/lcsc/smbj33a~g375.md)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410010132_Shikues-SMBJ33A_C499848.pdf
- Functional Group: Automotive Power
- Role Details: 33 V standoff TVS, cathode to VIN_PROTECTED and anode to GND
- JLCPCB Part Class: Extended Part
- Manufacturer Name: SHIKUES(时科)
- Product Info Url: https://lcsc.com/product-detail/TVS_Shikues-SMBJ33A_C499848.html
- LCSC Part Number: C499848
- Manufacturer Part Number: SMBJ33A
- Package or Case Code: SMB_L4.6-W3.6-LS5.3-RD
- Role: Surge Protection
- Part Type: TVS
**Pins:**
- A [pin 2]
- C [pin 1]
### D10 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- Manufacturer Name: worldsemi
- Manufacturer Part Number: WS2812B-Mini
- Role Details: LED bar pixel 6/8, 1.9 mm height; keep diffuser band free of tall components
- JLCPCB Part Class: Extended Part
- Role: Signal Generation
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
- Functional Group: LED Bar
- LCSC Part Number: C114583
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- Part Type: Light Emitting Diodes (LED)
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### D11 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- Manufacturer Name: worldsemi
- LCSC Part Number: C114583
- Role Details: LED bar pixel 7/8, 1.9 mm height; keep diffuser band free of tall components
- Functional Group: LED Bar
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Part Type: Light Emitting Diodes (LED)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- Manufacturer Part Number: WS2812B-Mini
- Role: Signal Generation
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### D12 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- LCSC Part Number: C114583
- Role: Signal Generation
- Functional Group: LED Bar
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- Part Type: Light Emitting Diodes (LED)
- Manufacturer Part Number: WS2812B-Mini
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
- Role Details: LED bar pixel 8/8, 1.9 mm height; final DOUT intentionally NC; keep diffuser band free of tall components
- Manufacturer Name: worldsemi
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### D13 — [1N4148W-13-F](https://www.flux.ai/lcsc/1n4148w-13-f~5cuh.md)
- JLCPCB Part Class: Extended Part
- Part Type: Switching Diode
- Role Details: AP63203 EN diode-OR: automotive 5 V enables immediately; USB-only path waits for CP2102N SUSPENDb deassertion
- LCSC Part Number: C112342
- Functional Group: 3V3 Power
- Role: Rectification
- Manufacturer Part Number: 1N4148W-13-F
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-1N4148W-13-F_C112342.pdf
- Product Info Url: https://lcsc.com/product-detail/Switching-Diode_DIODES_1N4148W-13-F_1N4148W-13-F_C112342.html
- Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD
- Manufacturer Name: DIODES(美台)
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D14 — [1N4148W-13-F](https://www.flux.ai/lcsc/1n4148w-13-f~5cuh.md)
- Product Info Url: https://lcsc.com/product-detail/Switching-Diode_DIODES_1N4148W-13-F_1N4148W-13-F_C112342.html
- Role: Rectification
- Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD
- Manufacturer Name: DIODES(美台)
- Functional Group: 3V3 Power
- Manufacturer Part Number: 1N4148W-13-F
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-1N4148W-13-F_C112342.pdf
- Part Type: Switching Diode
- Role Details: AP63203 EN diode-OR: automotive 5 V enables immediately; USB-only path waits for CP2102N SUSPENDb deassertion
- LCSC Part Number: C112342
- JLCPCB Part Class: Extended Part
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D2 — [USBLC6-2SC6](https://www.flux.ai/vasy_skral/usblc6-2sc6~g1b.md)
- Functional Group: USB and Programming
- Part Type: Protection
- License: https://creativecommons.org/licenses/by/4.0/
- Role: ESD Protection
- Manufacturer Part Number: USBLC6-2SC6
- Datasheet URL: https://www.st.com/content/ccc/resource/technical/document/datasheet/06/1d/48/9c/6c/20/4a/b2/CD00050750.pdf/files/CD00050750.pdf/jcr:content/translations/en.CD00050750.pdf
- Manufacturer Name: STMicroelectronics
- LCSC Part Number: C7519
- Symbol Style: parametric-v1
- Role Details: USB 2.0 D+/D- low-capacitance protection array
**Pins:**
- GND [pin 2]
- I/O1 [pin 6]
- I/O1 [pin 1]
- I/O2 [pin 3]
- I/O2 [pin 4]
- VBUS [pin 5]
### D3 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- Functional Group: Status Indicator
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- Part Type: Light Emitting Diodes (LED)
- LCSC Part Number: C114583
- Role Details: LED bar pixel 1/8, 1.9 mm height; GPIO25 via U8/R13; reserve diffuser band around D3,D6-D12 with no tall components
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
- Manufacturer Part Number: WS2812B-Mini
- Role: Status LED
- Manufacturer Name: worldsemi
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### D5 — [BZT52C12-7-F](https://www.flux.ai/lcsc/bzt52c12-7-f~p7ye.md)
- Manufacturer Name: DIODES(美台)
- Functional Group: Automotive Power
- Manufacturer Part Number: BZT52C12-7-F
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/user-uploaded/e61ab987678771beec3696d1c7c275077dbd85f43b0d1d018c1cb2a70c76f48f.pdf
- Product Info Url: https://lcsc.com/product-detail/Zener-Diodes_DIODES_BZT52C12-7-F_BZT52C12-7-F_C124196.html
- Role Details: 12 V zener from Q1 gate to source prevents exceeding ±20 V VGS
- JLCPCB Part Class: Extended Part
- Role: Gate Protection
- LCSC Part Number: C124196
- Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD
- Part Type: Zener Diodes
**Pins:**
- A [pin 2]
- C [pin 1]
### D6 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- Role: Signal Generation
- Functional Group: LED Bar
- Manufacturer Name: worldsemi
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Part Type: Light Emitting Diodes (LED)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- LCSC Part Number: C114583
- Role Details: LED bar pixel 2/8, 1.9 mm height; keep diffuser band free of tall components
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
- Manufacturer Part Number: WS2812B-Mini
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### D7 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- LCSC Part Number: C114583
- Role: Signal Generation
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- Part Type: Light Emitting Diodes (LED)
- Manufacturer Part Number: WS2812B-Mini
- Role Details: LED bar pixel 3/8, 1.9 mm height; keep diffuser band free of tall components
- Functional Group: LED Bar
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
- Manufacturer Name: worldsemi
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### D8 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- Role: Signal Generation
- LCSC Part Number: C114583
- Functional Group: LED Bar
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- Part Type: Light Emitting Diodes (LED)
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Manufacturer Part Number: WS2812B-Mini
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
- JLCPCB Part Class: Extended Part
- Role Details: LED bar pixel 4/8, 1.9 mm height; keep diffuser band free of tall components
- Manufacturer Name: worldsemi
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### D9 — [WS2812B-Mini](https://www.flux.ai/lcsc/ws2812b-mini~mucn.md)
- Manufacturer Name: worldsemi
- Role: Signal Generation
- Functional Group: LED Bar
- Role Details: LED bar pixel 5/8, 1.9 mm height; keep diffuser band free of tall components
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/Light-Emitting-Diodes-LED_3535-RGBIntegrated-Light_C114583.html
- Manufacturer Part Number: WS2812B-Mini
- Package or Case Code: LED-SMD_4P-L3.5-W3.5-TL_WS2812B
- Part Type: Light Emitting Diodes (LED)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Worldsemi-WS2812B-Mini_C114583.pdf
- LCSC Part Number: C114583
**Pins:**
- DIN [pin 4]
- DOUT [pin 2]
- VDD [pin 1]
- VSS [pin 3]
### F1 — [60MR-A](https://www.flux.ai/lcsc/60mr-a~j7ce.md)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1912171433_Littelfuse-2920L110-60MR-A_C468892.pdf
- JLCPCB Part Class: Extended Part
- Functional Group: Automotive Power
- Product Info Url: https://lcsc.com/product-detail/PTC-Resettable-Fuses_Littelfuse-2920L110-60MR-A_C468892.html
- Role: Protection
- Role Details: 2920L110/60MR-A, 1.1 A hold and 60 V; normal 12 V full-load input about 0.41 A, brief 6 V crank estimate about 0.88 A; validate hot derating
- LCSC Part Number: C468892
- Manufacturer Name: Littelfuse(美国力特)
- Manufacturer Part Number: 2920L110/60MR-A
- Package or Case Code: F2920
- Part Type: Resettable Fuses
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### J1 — [0436500200](https://www.flux.ai/adrian95/0436500200~dp5.md)
- Part Type: Connectors
- Role: Power Conversion
- Manufacturer Part Number: 43650-0200
- Functional Group: Automotive Power
- Datasheet URL: https://www.molex.com/pdm_docs/sd/436500200_sd.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Mount: PCB
- Manufacturer Name: Molex
- Role Details: Molex 43650-0200 / 0436500200 Micro-Fit 3.0, right-angle THT, snap-in PCB lock and positive-latch mating family; verified 5.57 mm board-side envelope; pin 1 +12V_SW, pin 2 GND
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### J2 — [USB-C 2.0 Receptacle](https://www.flux.ai/vasy_skral/usb-c-2p0-receptacle~1xw.md)
- Functional Group: USB and Programming
- Symbol Style: parametric-v1
- Datasheet URL: https://gct.co/files/drawings/usb4105.pdf
- Part Type: USB C
- Role Details: USB4105-GF-A USB-C 2.0 sink/device receptacle; SMT contacts with through-hole shell stakes, independent CC resistors; 3.31 mm body height above PCB
- Manufacturer Name: GTC
- Role: USB Connector
- Manufacturer Part Number: USB4105-GF-A
- Purchase Url: https://www.digikey.com/en/products/detail/gct/USB4105-GF-A/11198441
**Pins:**
- CC1 [pin 6]
- CC2 [pin 12]
- D- [pin 7]
- D- [pin 9]
- D+ [pin 10]
- D+ [pin 8]
- GND [pin 1]
- GND [pin 16]
- GND [pin 15]
- GND [pin 2]
- SBU1 [pin 11]
- SBU2 [pin 5]
- VBUS [pin 3]
- VBUS [pin 14]
- VBUS [pin 4]
- VBUS [pin 13]
### Q1 — [DMP6023LFG-7](https://www.flux.ai/lcsc/dmp6023lfg-7~nwpp.md)
- Manufacturer Part Number: DMP6023LFG-7
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-DMP6023LFG-7_C526579.pdf
- Functional Group: Automotive Power
- Role: Reverse Polarity Protection
- LCSC Part Number: C526579
- Package or Case Code: POWERDI3333-8_L3.3-W3.3-P0.65-BL
- Role Details: AEC-Q101 DMP6023LFG-7 P-channel MOSFET, -60 V, 25 mOhm max at -10 V; POWERDI3333-8 height 0.85 mm max; 12 V gate-source zener clamp
- Part Type: MOSFETs
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc.com/product-detail/MOSFET_Diodes-Incorporated-DMP6023LFG-7_C526579.html
- Manufacturer Name: DIODES(美台)
**Pins:**
- D [pin 5]
- G [pin 4]
- S [pin 2]
- S [pin 1]
- S [pin 3]
### Q2 — [MMBT3904LT1G](https://www.flux.ai/openpartlist/mmbt3904lt1g~s5.md)
- Role: Auto Reset Transistor
- Part Type: Transistor
- Manufacturer Name: onsemi
- Functional Group: Auto Reset
- Manufacturer Part Number: MMBT3904LT1G
- Role Details: DTR/RTS translation for ESP32 EN/GPIO0
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/mmbt3904lt1-d.pdf
**Pins:**
- B [pin 1]
- C [pin 3]
- E [pin 2]
### Q3 — [MMBT3904LT1G](https://www.flux.ai/openpartlist/mmbt3904lt1g~s5.md)
- Manufacturer Part Number: MMBT3904LT1G
- Manufacturer Name: onsemi
- Role Details: DTR/RTS translation for ESP32 EN/GPIO0
- Functional Group: Auto Reset
- Part Type: Transistor
- Datasheet URL: https://www.onsemi.com/pdf/datasheet/mmbt3904lt1-d.pdf
- Role: Auto Reset Transistor
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- B [pin 1]
- C [pin 3]
- E [pin 2]
### S1 — [434153017835](https://www.flux.ai/silicon-yard/434153017835.md)
- Part Type: Switch
- Role: Boot Switch
- Manufacturer Part Number: 434153017835
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/user-uploaded/a84c85dacf9aa62769303b09754c3b1c77674964659bf458883e051fe6023739.pdf
- Role Details: Momentary normally-open GPIO0-to-GND boot control
- Functional Group: MCU Core
- Manufacturer Name: Würth
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]
### TP1 — [TestPoint_Pad_1.0x1.0mm](https://www.flux.ai/adrian95/testpointpad10x10mm~77t.md)
- Part Type: Connector
- Role: Test Point
- Functional Group: Test Points
- Role Details: 3V3 rail test pad
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- 1 [pin 1]
### TP2 — [TestPoint_Pad_1.0x1.0mm](https://www.flux.ai/adrian95/testpointpad10x10mm~77t.md)
- Functional Group: Test Points
- Part Type: Connector
- Role Details: Ground test pad
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Test Point
**Pins:**
- 1 [pin 1]
### TP3 — [TestPoint_Pad_1.0x1.0mm](https://www.flux.ai/adrian95/testpointpad10x10mm~77t.md)
- Functional Group: Test Points
- Part Type: Connector
- Role Details: ESP32 EN test pad
- Role: Test Point
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- 1 [pin 1]
### TP4 — [TestPoint_Pad_1.0x1.0mm](https://www.flux.ai/adrian95/testpointpad10x10mm~77t.md)
- Part Type: Connector
- Functional Group: Test Points
- Role Details: ESP32 GPIO0 boot test pad
- Role: Test Point
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- 1 [pin 1]
### TP5 — [TestPoint_Pad_1.0x1.0mm](https://www.flux.ai/adrian95/testpointpad10x10mm~77t.md)
- Role Details: ESP32 TXD0 test pad
- Part Type: Connector
- License: https://creativecommons.org/licenses/by/4.0/
- Functional Group: Test Points
- Role: Test Point
**Pins:**
- 1 [pin 1]
### TP6 — [TestPoint_Pad_1.0x1.0mm](https://www.flux.ai/adrian95/testpointpad10x10mm~77t.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Functional Group: Test Points
- Role Details: ESP32 RXD0 test pad
- Role: Test Point
- Part Type: Connector
**Pins:**
- 1 [pin 1]
### U1 — [ESP32-WROOM-32E-N4](https://www.flux.ai/lcsc/esp32-wroom-32e-n4~cokv.md)
- Operating Temperature: –40 ~ 85 °C
- JLCPCB Part Class: Extended Part
- Frequency: 2412 ~ 2484 MHz
- Manufacturer Part Number: ESP32-WROOM-32E-N4
- Role: Wireless MCU
- Product Info Url: https://lcsc.com/product-detail/WIFI-Modules_Espressif-Systems-ESP32-WROOM-32E-4MB_C701341.html
- Role Details: Main ESP32 controller; WROOM-32E/32UE pad-compatible footprint; GPIO25 drives LED bar; module height 3.25 mm max (3.1 +/-0.15 mm)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410301607_Espressif-Systems-ESP32-WROOM-32E-N4_C701341.pdf
- Operating Voltage: 3.0 ~ 3.6 V
- LCSC Part Number: C701341
- Functional Group: MCU Core
- Part Type: WiFi Modules
- Manufacturer Name: ESPRESSIF(乐鑫)
- Package or Case Code: WIFI-SMD_ESP32-WROOM-32E
**Pins:**
- 3V3 [pin 2]
- EN [pin 3]
- GND [pin 38]
- GND [pin 15]
- GND [pin 39]
- 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 17]
- NC [pin 32]
- NC [pin 19]
- NC [pin 21]
- NC [pin 20]
- NC [pin 22]
- NC [pin 18]
- RXD0 [pin 34]
- SENSOR_VN [pin 5]
- SENSOR_VP [pin 4]
- TXD0 [pin 35]
### U2 — [LM65645SRZTRQ1](https://www.flux.ai/silicon-yard/lm65645srztrq1.md)
- Symbol Style: parametric-v1
- Functional Group: Automotive Power
- Role Details: Automotive VIN_PROTECTED to AUTO_5V; fixed 5 V via FB-to-VCC, 2.2 MHz, 1.5 uH and >=25 uF effective output; approximately 0.9 A system load
- Package or Case Code: 20-WFQFN Exposed Pad
- Manufacturer Part Number: LM65645SRZTRQ1
- Manufacturer Name: Texas Instruments
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/user-uploaded/66a5596410ea65e697b50148afbb994976ab01079629c675a073b9d02c373bf6.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Power Management
- Role: Buck Regulator
**Pins:**
- BIAS [pin 20]
- BOOT [pin 15]
- DAP [pin 21]
- EN_UVLO [pin 7]
- FB [pin 3]
- MODE_SYNC [pin 5]
- NC [pin 18]
- NC [pin 10]
- NC [pin 12]
- NC [pin 16]
- NC1 [pin 1]
- NC2 [pin 8]
- PG [pin 2]
- PGND1 [pin 9]
- PGND2 [pin 19]
- RT [pin 6]
- SW1 [pin 13]
- SW2 [pin 14]
- VCC [pin 4]
- VIN1 [pin 11]
- VIN2 [pin 17]
### U3 — [CP2102N-A02-GQFN28](https://www.flux.ai/jecstronic/cp2102n-a02-gqfn28~mvt.md)
- Manufacturer Part Number: CP2102N-A02-GQFN28
- Role Details: USB-powered CP2102N bridge; configure Bus-Powered Max Power for intended USB-only load; SUSPENDb enables U4 after enumeration
- Role: USB-UART Bridge
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://componentsearchengine.com/Datasheets/2/CP2102N-A02-GQFN28.pdf
- Manufacturer Name: Silicon Labs
- Part Type: Integrated Circuit
- Functional Group: USB and Programming
**Pins:**
- BGND [pin 29]
- CHR0 [pin 15]
- CHR1 [pin 14]
- CHREN [pin 13]
- CTS [pin 23]
- D- [pin 5]
- D+ [pin 4]
- DCD [pin 1]
- DSR [pin 27]
- DTR [pin 28]
- GND [pin 3]
- GPIO.0/TXT [pin 19]
- GPIO.1/RXT [pin 18]
- GPIO.2/RS485 [pin 17]
- GPIO.3/WAKEUP [pin 16]
- GPIO.4 [pin 22]
- GPIO.5 [pin 21]
- GPIO.6 [pin 20]
- NC [pin 10]
- RI/CLK [pin 2]
- RSTB [pin 9]
- RTS [pin 24]
- RXD [pin 25]
- SUSPEND [pin 12]
- SUSPENDB [pin 11]
- TXD [pin 26]
- VBUS [pin 8]
- VDD [pin 6]
- VREGIN [pin 7]
### U4 — [AP63203WU-7](https://www.flux.ai/adrian95/ap63203wu-7~o8a.md)
- Datasheet URL: https://www.diodes.com/assets/Datasheets/AP63200-AP63201-AP63203-AP63205.pdf
- Manufacturer Name: Diodes Incorporated
- Role Details: Common 5 V to 3.3 V, 2 A buck; supports ESP32 500 mA peaks plus logic margin; 3.9 uH, 10 uF input and 2x22 uF output per datasheet
- Manufacturer Part Number: AP63203WU-7
- Functional Group: USB Power
- Part Type: Integrated Circuit
- License: https://creativecommons.org/licenses/by/4.0/
- Symbol Style: parametric-v1
- Role: Power Conversion
**Pins:**
- BST [pin 6]
- EN [pin 2]
- FB [pin 1]
- GND [pin 4]
- SW [pin 5]
- VIN [pin 3]
### U5 — [LM66100DCKR](https://www.flux.ai/lcsc/lm66100dckr~n7rd.md)
- Manufacturer Part Number: LM66100DCKR
- Symbol Style: parametric-v1
- Functional Group: Power ORing
- Role Details: LM66100 ideal diode from AUTO_5V to common 5V; 1.5 A rated, CE tied to VOUT for reverse-current blocking
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/user-uploaded/073d95fd957eb97860bc1955e3d8437c849217e594930e2542a315ec77cc0da2.pdf
- Role: Ideal Diode
- LCSC Part Number: C2869734
- Part Type: Integrated Circuit
- Manufacturer Name: TI(德州仪器)
- Package or Case Code: SC-70-6_L2.0-W1.3-P0.65-LS2.1-BL
- JLCPCB Part Class: Extended Part
**Pins:**
- ~{CE} [pin 3]
- GND [pin 2]
- NC [pin 4]
- ST [pin 5]
- VIN [pin 1]
- VOUT [pin 6]
### U6 — [LM66100DCKR](https://www.flux.ai/lcsc/lm66100dckr~n7rd.md)
- Symbol Style: parametric-v1
- Role: Ideal Diode
- Manufacturer Part Number: LM66100DCKR
- Functional Group: Power ORing
- LCSC Part Number: C2869734
- Role Details: LM66100 ideal diode from USB_VBUS to common 5V; 1.5 A rated, CE tied to VOUT for reverse-current blocking; USB source current is not assumed unlimited
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/user-uploaded/073d95fd957eb97860bc1955e3d8437c849217e594930e2542a315ec77cc0da2.pdf
- Part Type: Integrated Circuit
- Package or Case Code: SC-70-6_L2.0-W1.3-P0.65-LS2.1-BL
- Manufacturer Name: TI(德州仪器)
- JLCPCB Part Class: Extended Part
**Pins:**
- ~{CE} [pin 3]
- GND [pin 2]
- NC [pin 4]
- ST [pin 5]
- VIN [pin 1]
- VOUT [pin 6]
### U8 — [74AHCT1G125W5-7](https://www.flux.ai/lcsc/74ahct1g125w5-7~t6h6.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: DIODES(美台)
- Role Details: AHCT buffer powered from LED_5V; 2.0 V VIH accepts ESP32 3.3 V output
- LCSC Part Number: C842287
- Role: Logic Level Shifter
- Part Type: Buffers / Drivers
- Manufacturer Part Number: 74AHCT1G125W5-7
- Functional Group: Status Indicator
- Symbol Style: parametric-v1
- Package or Case Code: SOT-25-5_L3.0-W1.6-P0.95-LS2.8-BL
- Datasheet URL: https://www.lcsc.com/datasheet/C842287.pdf?spm=wm.sxq.inf.ggs&lcsc_vid=FlkNBAIDRQULVABfFAVZBgZVFVZYBgZSQ1NeBVIFQlExVlNeR1VbVlZfRVhaVzsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- JLCPCB Part Class: Extended Part
**Pins:**
- ~{OE} [pin 1]
- A [pin 2]
- GND [pin 3]
- Vcc [pin 5]
- Y [pin 4]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/scorp1084/heimdall-bypass~7u](https://www.flux.ai/scorp1084/heimdall-bypass~7u).*
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*Generated from [https://www.flux.ai/scorp1084/heimdall-bypass~7u](https://www.flux.ai/scorp1084/heimdall-bypass~7u)*