Validation - BMS Carrier

Power Validation

• Check for continuity between GND, 3.3 V, 5 V, and 12 V. All of these should be isolated from each other.
• Remove R23.
• Supply 12 V between GND and 12 V. Measure the voltage between GND and 3.3 V, and GND and 12 V.
• Enable the 5 V converter. Measure the voltage between GND and 5 V.
• Connect an oscilloscope probe between GND and 5 V to measure the ripple of the 5 V converter.

HSD Current Sense Output

• Connect the E-load between the HSD side of the kill switch connector, and GND.
• Supply 12 V between GND and 12 V.
• Enable IN2 and DIAG_EN of the HSD (PB8 and PB9).
• Set the E-load to draw 100 mA.
• Measure the voltage across D2. If it is 3.3 V, then R23 can be added.

isoSPI Enable

• Connect a controller board to the BMS carrier.
• Connect two oscilloscope probes; one between GND and IP and one between GND and IN. Set the oscilloscope to output IP - IN. Alternatively, connect one oscilloscope probe between GND and the LTC6820 IBIAS pin (pin 16).
• Supply 12 V between GND and 12 V.
• Set the CS pin of the LTC6820 being tested low, then high again.
• If the LTC6820 is enabled, there will be a long +1 pulse transmitted between IP and IN, or the IBIAS pin will be set to 2 V.
• Repeat for each SPI.

Relay Capacitor Inrush Current

• Connect a shunt resistor between the negative terminal of the power supply and the negative terminal of the BMS carrier board.
• Connect an oscilloscope probe across the shunt resistor, with the ground terminal of the probe connected to the negative terminal of the power supply. Set the oscilloscope to trigger a single time.
• Power the BMS carrier board with 12 V between 12 V and the negative terminal of the shunt resistor. Toggle the output of PB9 on and off. Turn off the power supply.
• Determine the peak voltage, and divide by the resistance of the shunt resistor. The peak current should be less than 1 A.