Four .cir behavioral simulations ready to open in LTspice via File→Open:
1_buck_chain.cir — dual MP2338 12V→5V→3.3V, verifies Rfb math + soft-start
2_output_stage.cir — PC817 + IRLML6344 isolated output (inverted logic confirmed)
3_analog_input.cir — analog input conditioning; flags ADC overvoltage on IN-BAT/WATER/OILP
4_nmea2000_can.cir — MCP2562T CAN transceiver, two-node NMEA2000 bus, T-line model
CRITICAL finding in 3_analog_input.cir: R_high=10K + R_low=15K gives 4.3V
at ESP32 ADC when measuring a 12V battery — exceeds 3.3V limit. Fix: use
R_high=100K (same as IN-RPM, which is correctly designed at 3.06V @ 14.4V).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
