Compact PCB Design Requirements

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Work completed
  • Project description updated for EG912U swap and feature hashtags
  • System architecture diagram rewritten and saved
  • Added U8 and U9 (TPD4E02B04DQA) on USB lines
  • Added Quectel EG912U module to schematic
  • Placed decoupling caps on U4, U5, U6, U7 and EG912U/eSIM
  • Configured R1, R2 as 5.1 kΩ CC pull-downs
  • Added SIM/eSIM interface load resistors (R3–R5)
  • Wired power, UART, SIM/eSIM nets per plan
  • Researched and added RF π-match network (C16, L1, C17)
  • Routed RF network to u.FL (J2)
  • Severed BG95 USB nets; routed D+/D– exclusively to ESP32-C6
  • Connected TVS diodes to GND
  • Updated all capacitor voltage ratings and resistor power ratings
  • Replaced under-rated passives and removed originals
  • Verified footprints and set 4-layer stackup (L2 GND, L3 power)
  • Added mounting holes and set ground fill on L1/L4
  • Assigned MPNs to U8/U9
  • Fetched and updated LifecycleStatus for all BOM parts
Tasks unable to perform
  • Automated schematic review for missing decoupling or ratest issues (steps 5.1–5.3)
  • Fetching layout bounding box and resizing board to 5 mm margin (6.3–6.4)
  • Classify nets and set impedance rules (7.1–7.2)
  • Component placement auto-layout (8.1)
  • Auto-routing USB, RF, and remaining nets (9.1–9.3)
  • Running DRC and fixing violations (10.1–10.2)
  • Assigning MPNs to generic resistors (11.2)
  • Fetching availability data and updating Availability properties (11.3.1, 11.3.3)
Success criteria review
  • EG912U integration: ❌ BG95M3 remains present; EG912U not yet substituted
  • USB-C data routing: ✅ now goes exclusively to ESP32-C6 with CC pull-downs and TVS
  • Power management: ✅ charger, buck regulator, load switch, push-button controller all interfaced
  • PCB stack-up and impedance: ❌ layout rules, board sizing, and routing not yet complete
Next step
Define layout rules and manually classify nets by type (USB differential, RF, power, signal) so we can set controlled-impedance constraints before placing and routing on the board.
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Ultra-Compact 4-Layer ESP32-C6 + Quectel EG912U LTE Dev Board w/ Onboard eSIM, π-Match RF Tuning, Optional u.FL, USB-C Data (ESP32-C6 Only), USB-C Battery Charging, Controlled Impedance Routing #EG912U #USBDataOnly #USBCharging #4Layer #eSIM

Properties

Diagram



  
    
  
  
    
  



""Quectel EG912U""


""ESP32-C6""


""Power Path""


""USB-C Port""


""Onboard eSIM""


""RF Match Network""









UART CTS/RTS

VBUS Detect

SIM IO/CLK/RST

u.FL Connector
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Diagram



  
    
  
  
    
  



Cellular Module[BG95M3]


""ESP32-C6""


USB-C Interface


Power Sequencing












UART

UART

CTS

RTS
















Main Flow Control
Main Flow Control
USIM_IO
IO
USIM_CLK
USIM_RST
Main_CTS
BG95_MAIN_CTS
Main_RTS
BG95_MAIN_RTS
GPIO
J1
PushBtn
ON
PWRKEY
3V3 rail
Ω

Pricing & Availability

Distributor

Qty 1

Arrow

$25.96–$30.66

Digi-Key

$30.05–$33.09

LCSC

$17.56

Mouser

$45.15

TME

$5.50

Verical

$42.80–$49.13

Controls