Copper Review / 01-SICk-CANary

Pre-fab review report

Hold
revise first

Schematic intent is coherent. Release risk is still real.

1 block-fab

1 high candidate

2 medium candidates

Findings

block-fab

J2/J3 assembly part does not appear to match the PCB footprint.

findingJ2 J3

Evidence: BOM uses 1840379 / C480579. The PCB footprint is Phoenix MCV 1x03 vertical header style, whose library description references header order 1843619.

Action: Choose the exact assembled connector. Update the BOM to the PCB header, or change the footprint if the populated part is different.

Schematic crop

J2/J3 connector evidence

The schematic side shows the two external CAN connector blocks; the report ties this to the assembled connector and PCB footprint mismatch.

high

CAN TVS part is a normal-capacitance substitute.

candidateD7 D8

Evidence: LCSC C39832198 resolves to ElecSuper PESD2CANFD24V-TR. Its datasheet lists CJ 18 pF typical, 35 pF max and calls the part Normal Capacitance ESD. Two devices sit on the CAN pair.

Action: Use a proven low-cap CAN FD TVS, or explicitly accept this capacitance and clamp tradeoff after signal-integrity review.

Schematic crop

TVS capacitance check

The highlighted TVS diode matches a generic part number with higher capacitance than typical for CAN FD.

medium

CAN netclass looks broader than the electrical intent.

candidateconstraints

Evidence: Copper reports GND and split-termination local nets in the CAN class. KiCad DRC still applies CAN clearance checks to nearby local pads.

Action: Make release constraints explicit: usually /CAN_P and /CAN_N get the CAN class; split, ground, and local pads only if intentionally included.

Schematic crop

Netclass scope

Showing the local termination nets that incorrectly inherited the strict CAN clearance class.

Checked OK

U2 TJA1462 pin map matches the datasheet order.
/CAN_P = CANH and /CAN_N = CANL matches the supplied design intent.
R9/R10 split termination gives 120.8 ohm total; C3 = 4.7 nF, 100 V is defensible.

Watch list

Termination switch needs clear ON/OFF marking.
Switch-off state leaves small floating pads/stubs on CAN.
J1/J2/J3 pin-1 orientation still needs harness signoff.

Evidence used

Copper scan: 37 components, 24 nets, 14 detected features.
KiCad ERC: 0 schematic ERC violations.
KiCad DRC: 136 violations, including track width and footprint mismatch warnings.

Board snapshot