The LM74700-EP is an 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 many popular DC bus voltages such as 12-V, 24-V and 48-V 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 ensures zero DC reverse current flow. Fast response (< 0.75 µs) to Reverse Current Blocking makes the device suitable for systems with output voltage holdup requirements during power fail and input micro-short conditions.
The LM74700-EP controller provides a charge pump gate drive for an external N-channel MOSFET. The high voltage rating of LM74700-EP helps to simplify the system designs for automotive ISO7637 protection. With the enable pin low, the controller is off and draws approximately 1 µA of current. The LM74700-EP is fully specified over the temperature range of TA = –55°C to +125°C.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
LM74700-EP | SOT-23 (8) | 2.90 mm × 1.60 mm |
DATE | REVISION | NOTES |
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September 2021 | * | Initial Release |
PIN | I/O(1) | DESCRIPTION | |
---|---|---|---|
NO. | NAME | ||
1 | EN | I | Enable pin. Can be connected to ANODE for always ON operation. |
2 | GND | G | Ground pin |
3 | N.C | No connection. Keep this pin floating. | |
4 | VCAP | O | Charge pump output. Connect to external charge pump capacitor. |
5 | ANODE | I | Anode of the diode and input power. Connect to the source of the external N-channel MOSFET. |
6 | GATE | O | Gate drive output. Connect to gate of the external N-channel MOSFET. |
7 | N.C | No connection. Keep this pin floating. | |
8 | CATHODE | I | Cathode of the diode. Connect to the drain of the external N-channel MOSFET. |