In some examples, the disclosure includes a circuit including a power field effect transistor (FET), a gate pull-down circuit, a pull-down bias circuit, and a radio frequency (RF) detector coupled to the source terminal of the power FET and the pull-down bias circuit. In an example, the RF detector circuit is configured to detect a presence of an alternating current signal at a source terminal of the power FET when the power FET is in a non-conductive state and control the pull-down bias circuit to bias the gate pull-down circuit to create a low impedance path between a gate terminal of the power FET and the source terminal of the power FET when the power FET is in the non-conductive state and the alternating current signal is present at the source terminal of the power FET.