TIDUFE6A September 2025 – December 2025
Solenoids are non-latching, if there is no current driving the solenoid the solenoid returns to the default – open – state. Therefore, the solenoid does not require a direction control like the lock mechanism based on a motor.
For this purpose, the DRV8220 can be configured in half-bridge mode by disconnecting jumper J12. The DRV8220 requires no extra external diodes for the use with solenoids, as the other FETs and body diodes in the half-bridge recirculate freewheeling current during the off-time of the PWM duty cycle. The solenoid should be connected to the connector positive terminal J13 pin 1 (LO+) and negative terminal J13 pin 3 (LO – CDM).
Figure 2-20 CHAdeMO Pluck Lock Feedback CircuitThe CHAdeMO charging plug is equipped with an internal switch, that connects the solenoid to the power supply only if the plug is completely mated with the inlet. This prevents the activation of the solenoid in any other state than mated with the inlet of the EV.
To proof if the plug is locked into the inlet, the current consumption of the solenoid can be monitored. Therefore, a shunt resistor is added to between GND and the LO - CDM connector. As soon as the solenoid is active, current flows through the shunt resistor resulting in a voltage drop above it. The voltage drop enables the output of the comparator U18, setting MSP_GPIO_PL_CdM_FB to logic high and enabling LED D28.
The threshold for the comparator is generated by a precision programmable reference TL431AQ. In this configuration R113 limits the cathode current to 5.5mA. The output of the TL431AQ device is 2495mV, which is further reduced to 14.6mV through a voltage divider formed by R114 and R115.
The shunt resistor has a resistance of 0.5Ω. This leads to a voltage drop equal to the reference voltage at 30mA, which is less than the typical current consumption of a solenoid.