The LM74502-Q1, LM74502H-Q1 is an automotive AEC-Q100 qualified controller which operates in conjunction with an external back-to-back connected N-channel MOSFETs as a low loss reverse polarity protection and load disconnect solution. 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 automotive battery systems. The 3.2-V input voltage support is particularly well suited 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 LM74502-Q1, LM74502H-Q1 does not have reverse current blocking and is suitable for input reverse polarity protection of loads that can potentially deliver energy back to the input supply such as automotive body control module motor loads.
The LM74502-Q1 controller provides a charge pump gate drive for an external N-channel MOSFET. The high voltage rating of LM74502-Q1 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, thus offering low system current when put into sleep mode. LM74502-Q1 offers programmable overvoltage and undervoltage protection which cuts off the load from the input source in case of these faults.
- AEC-Q100 qualified with the following results
- Device temperature grade 1: –40°C to +125°C ambient operating temperature range
- Device HBM ESD classification level 2
- Device CDM ESD classification level C4B
- 3.2-V to 65-V input range (3.9-V start-up)
- –65-V input reverse voltage rating
- Integrated charge pump to drive
- External back-to-back N-Channel MOSFETs
- External high side switch MOSFET
- External reverse polarity protection MOSFET
- Gate drive variants
- LM74502-Q1: 60-µA peak gate drive source capacity
- LM74502H-Q1: 11-mA peak gate drive source capacity
- 2-A peak gate sink capacity
- 1-µA shutdown current (EN/UVLO = Low)
- 45-µA typical operating quiescent current (EN/UVLO = High)
- Adjustable overvoltage and undervoltage protection
- Meets automotive ISO7637 pulse 1 transient requirements with additional TVS diode
- Available in 8-pin SOT-23 package 2.90 mm × 1.60 mm