PCB Design for LED Project

Work done
  • Completed BMS external protection wiring around IC1: added shunt R9 to IC1 SRP/SRN, added back-to-back protection FETs Q1/Q2 driven by IC1 DSG/CHG, and wired cell-tap connector J3 into the BMS sense pins with RC filtering.
  • Enforced arm-switch series path by wiring U5 in series between pack positive and load rail: PACK_B+ -> U5 -> LOAD+.
  • Implemented a hardware charge interlock so the LED driver is forced off during charging by pulling U1 SHDN/UVLO low via Q3 from charger status.
  • Set the PCB layout size to 40.0 mm x 50.0 mm.
Success criteria review
  • ✅ The BMS protection circuitry is integrated with IC1 including shunt + CHG/DSG FET gating.
  • ✅ The off-board arm switch interface U5 is wired in series between pack and load.
  • ✅ The LED driver U1 is hard-disabled during charging using charger status hardware interlock.
  • ❌ DRC is not passing because the PCB is not placed/routed (Airwires remain). I cannot auto-route or place components.
Next steps
  • Place parts and run Flux Auto-Layout routing (or route manually). After that, I can re-run DRC (especially Airwires/Overlapping Copper/Floating Copper) and help you clear remaining violations.
why is autolayout not working
I could not find relevant Flux documentation that explains why Auto-Layout is not working or how to troubleshoot it (the docs results I found only cover starting PCB layout and general routing/wiring, not Auto-Layout failures).
The closest related entry I found is about starting PCB layout:
Click the PCB tab. Your schematic components become footprints on the board. Define the board outline and arrange components based on the ratsnest.
For more help, try:
If Auto-Layout is failing due to a bug (button does nothing, errors, etc.), contact Flux support: Contact Support.
Check layout review
Board outline set?
Inspect U2 placement
See schematic connectivity
U2
U2 STAT1 - R8 P1
U2 _PG - U4 PA4
U2 SCL - IC1 SCL
U2 PGND - IC3 PGND
IC3 VOUT_3 - C8 P1
J2 Outer_Contact - C1 P2
IC1 VSS - U2 PGND
U3 ANT - J2 Center_Contact
U3 DATA - U4 PA0
IC3 VOUT_3 - C8 P1
U2 PGND - IC3 PGND
J1 VBUS__1 - C5 P1
U4 VDDA - C1 P1
J1 VBUS__1 - C5 P1
J1 VBUS__1 - C5 P1
J1 SHELL_GND__3 - J2 Outer_Contact
U2 STAT2 - U4 PA3
U2 PGND - IC3 PGND
IC3 VOUT_3 - C8 P1
U3 ANT - J2 Center_Contact
U2 STAT1 - R10 P1
U2 SDA - IC1 SDA
R3
Resistance
0.1 Ω
L1
Inductance
10uH
IC2
J2
U3


Led lampa uznemej 1 thumbnail
6S Li-ion USB-C charged 40V/0.75A PWM-dim LED driver with 433MHz remote

Properties

Pricing & Availability

Distributor

Qty 1

Arrow

$22.81–$22.89

Digi-Key

$29.14–$30.30

LCSC

$48.46

Mouser

$35.43

TME

$22.75

Verical

$6.09–$11.12

Controls