Abstract: A device includes a power converter having an input coupled to a first node and an output coupled to an output terminal adapted to couple to a battery. A blocking transistor is coupled between a second node and the first node. A regulator has inputs coupled to the first node and the second node and an output coupled to a control node of the blocking transistor. The regulator is configured to control the blocking transistor to regulate a voltage drop across the blocking transistor based on a voltage between the first node and the second node. The regulator is also configured to turn off the blocking transistor in response to a voltage at the first node exceeding a voltage at the second node by at least a threshold to block boost-back current flowing from the output terminal to the second node.