The LM74720-Q1 ideal diode controller drives and controls external back-to-back N-Channel MOSFETs to emulate an ideal diode rectifier with power path ON and OFF control and overvoltage protection. The wide input supply of 3 V to 65 V allows protection and control of 12-V and 24-V automotive battery powered ECUs. IQ during operation (EN = High) is < 35 µA and < 3.3 µA during shutdown mode (EN = Low). The device can withstand and protect the loads from negative supply voltages down to –65 V. An integrated ideal diode controller (GATE) drives the first MOSFET to replace a Schottky diode for reverse input protection and output voltage holdup. A strong 29-mA boost regulator and short turn-ON and turn-OFF delay times of comparators ensures fast transient response ensuring robust and efficient MOSFET switching performance during automotive testing such as ISO16750 or LV124 where an ECU is subjected to input short interruptions and AC superimpose input signals up to 100-kHz frequency. The device features an adjustable over voltage cut-off protection feature for load dump protection.

The LM74720-Q1 controls the GATE of the MOSFET to regulate the forward voltage drop at 17 mV. The linear regulation scheme in these devices enables graceful control of the GATE voltage and turns off of the MOSFET during a reverse current event and ensures zero DC reverse current flow.

Low quiescent current (< 35 µA) in operation enables always ON system designs. With a second MOSFET in the power path, the device allows load disconnect control using EN pin. Quiescent current reduces to 3.3 μA with EN low.