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Due to changing a new regulations, charging must now have a relay.

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This circuit is copied from the BMS carrier. PB0 is one of the two pins that must be enabled to activate the relay.

HV_PWR_RELAY_12V_SW will carry 12V once the load switch is enabled. This causes inrush current.

Maximum inrush current = C*dv/dt = 49.2e-6*0.9e6 = 44.2 A.
Typical inrush current = 49.2e-6*0.6e6 = 29.52 A.
Minimum inrush current = 49.2e-6*0.3e6 = 14.76 A.

This may trigger overcurrent protection on the load switch, but it should resume normal operation after the current settles after a few microseconds.

Load Switch

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datasheet: https://www.infineon.com/dgdl/Infineon-BTS7040-1EPA-DS-v01_00-EN.pdf?fileId=5546d462636cc8fb0163fe8f965308bc

PB8 is the other pin that must be enabled to activate the relay. PB9 and PA3 are used for diagnostics (more information is in the data sheet).