The LM74703-Q1 and LM74704-Q1 ideal diode controllers have all the features necessary to implement an efficient and fast reverse polarity protection circuit. The devices can be used in an ORing 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 like a P-channel MOSFET or a Schottky diode. An internal charge pump drives the external N-Channel MOSFET to a maximum gate-to-source drive voltage of approximately 12 V. The voltage drop across the MOSFET is continuously monitored between the ANODE and CATHODE pins, and the GATE to ANODE pin voltages are 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 provides zero DC reverse current flow. A fast reverse current condition is detected when the voltage across the ANODE and CATHODE pins reduces below –11 mV. This behavior connects the GATE pin internally 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 LM74703-Q1 in shutdown mode, disabling the N-Channel MOSFET and minimizing the quiescent current.

LM74703-Q1 and LM74704-Q1 offer an external FET health monitoring feature with the FETGOOD pin. The device monitors for external FET drain-to-source short or open condition during power-up and pulls the FETGOOD pin low in case the external FET fault condition is diagnosed.

For automotive applications like automotive lighting, camera modules that are typically exterior facing require low conducted and radiated emissions in the frequency band ranging up to few Gigahertz (GHz). LM74703-Q1 and LM74704-Q1 offer low emissions in high-frequency band, making these devices a good candidate for applications where emissions in high-frequency band are a key consideration.