LM74703-Q1

The LM74703-Q1, LM74704-Q1 is an automotive AEC Q100 qualified ideal diode controller which operates in conjunction with an external N-channel MOSFET as an ideal diode rectifier for low-loss reverse polarity protection with a 20-mV forward voltage drop. The wide supply input range of 3.2 V to 65 V allows control of popular DC bus voltages such as 12-V, 24-V, and 48-V automotive battery systems. The 3.2-V input voltage support is designed especially for severe cold crank requirements in automotive systems. The device can withstand and protect the loads from negative supply voltages down to –65 V.

The device controls the gate of the MOSFET to regulate the forward voltage drop at 20 mV. The regulation scheme enables graceful turn off of the MOSFET during a reverse current event and provides zero DC reverse current flow. Fast response (< 0.75 µs) to reverse current blocking makes the device applicable for systems with output voltage holdup requirements during ISO7637 pulse testing as well as power fail and input micro-short conditions. LM74703-Q1, LM74704-Q1 has FETGOOD output to indicate external MOSFET drain to source short or open condition. The device features enable pin (EN). With the enable pin low, the controller is off and draws approximately 1-µA of current.