IN-VEHICLE POWER SUPPLY DEVICE

The present disclosure aims to avoid a situation where a drive unit to be used for precharge does not drive due to a drop in power supply voltage. The power supply device is provided with the first voltage conversion unit and the control unit. The first voltage conversion unit performs a third voltage conversion operation in which a voltage applied to a second conductive path is boosted and an output voltage is output to a first conductive path to which a capacitive component is electrically connected. The control unit supplies the third control signal to only some of the plurality of first voltage conversion units, thereby causing the some of the first voltage conversion units to perform the third voltage conversion operation.