SNOSDF5 September 2023 LM74700D-Q1
PRODUCTION DATA
The LM74700D-Q1 ideal diode controller has all the features necessary to implement an efficient and fast reverse polarity protection circuit or be used in an OR-ing configuration while minimizing the number of external components. This easy to use ideal diode controller is paired with an external N-channel MOSFET to replace other reverse polarity schemes such as a P-channel MOSFET or a Schottky diode. An internal charge pump is used to drive the external N-Channel MOSFET to a maximum gate drive voltage of approximately 15 V. The voltage drop across the MOSFET is continuously monitored between the ANODE and CATHODE pins, and the GATE to ANODE voltage is adjusted as needed to regulate the forward voltage drop at 20 mV. This closed loop regulation scheme enables graceful turn-off of the MOSFET during a reverse current event and make sure of zero DC reverse current flow. A fast reverse current condition is detected when the voltage across ANODE and CATHODE pins reduces below –11 mV , resulting in the GATE pin being internally connected to the ANODE pin turning off the external N-channel MOSFET, and using the body diode to block any of the reverse current. An enable pin, EN, is available to place the LM74700D-Q1 in shutdown mode disabling the N-Channel MOSFET and minimizing the quiescent current.