LTC3901 is a secondary side synchronous rectifier driver designed to be used in isolated push-pull and full bridge converter power supplies. The chip drives two external N-channel MOSFETs and accepts a transformer generated bipolar input to maintain synchronization with the primary side controller. It provides a full range of protection features for the external MOSFETs. A programmable timeout function is included that disables both drivers when the synchronization signal is missing or incorrect. Additionally, the chip senses the output inductor current through the drain-source resistance of the two MOSFETs, turning off the MOSFETs if the inductor current reverses. It also shuts off the drivers if the supply is low or if the synchronization sequence is incorrect. It is used in application such as 48V input isolated DC/DC converters, isolated telecom power supplies, distributed power step-down converters, industrial control system power supplies, automotive and heavy equipment etc.