Techniques are disclosed to regulate an output of a power converter. One example power converter controller circuit includes a line sense input to be coupled to receive a signal representative of an input voltage of a power converter. A feedback input is included and is to be coupled to receive a feedback signal representative of an output of the power converter. A drive signal generator is included and is to generate a drive signal coupled to control switching of a switch to provide a regulated output parameter at the output of the power converter in response to the feedback signal. The drive signal generator is to latch the power converter into an off state in response to a detection of a loss of regulation of a power converter output parameter if the input voltage of the power converter is above a threshold level. The drive signal generator is to be unresponsive to the signal representative of the input voltage of the power converter while the power converter output parameter is in regulation.