Summary of LM74500-Q1 REVERSE POLARITY PROTECTION CONTROLLER
Texas Instruments’ LM74500-Q1 is an AEC-Q100 automotive reverse-polarity protection controller that drives an external N-channel MOSFET via a charge pump. It supports 3.2 V to 65 V inputs (3.9 V start-up), endures −65 V reverse voltage, and suits 12 V/24 V/48 V DC bus systems and cold-crank conditions. With low shutdown current (1 µA) and 80 µA typical operating quiescent current, it helps meet ISO7637 transient requirements (with a TVS diode). Packaged in an 8-pin SOT-23, it targets body electronics and lighting applications.
Parts used in the LM74500-Q1 Reverse Polarity Protection Controller Project:
- LM74500-Q1 controller (AEC-Q100 qualified)
- External N-channel MOSFET
- TVS diode (for ISO7637 pulse protection)
- 8-pin SOT-23 package (LM74500-Q1 form factor)
- Enable pin connection (logic/control signal)
- Automotive DC bus (12 V, 24 V, or 48 V supply)
Texas Instruments’ controller is suitable for applications such as body electronics and lighting
Texas Instruments’ LM74500-Q1 is an automotive AEC-Q100 qualified controller which operates in conjunction with an external N-channel MOSFET as a low-loss reverse polarity protection solution. The wide supply input range of 3.2 V to 65 V allows control of 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 LM74500-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 LM74500-Q1 controller provides a charge pump gate drive for an external N-channel MOSFET. The high voltage rating simplifies the system designs for automotive ISO7637 protection. With the enable pin low, the controller is off and draws approximately 1 µA of current, offering low system current when put into sleep mode.
- AEC-Q100 qualified:
- Ambient temperature range Grade 1: -40°C to +125°C
- Device HBM ESD Classification Level 2
- Device CDM ESD Classification Level C4B
- Input range: 3.2 V to 65 V (3.9 V start-up)
- Input reverse voltage: -65 V
- Charge pump for an external N-Channel MOSFET
- Enable pin feature
- Shutdown current: 1 µA (EN=low)
- Typical operating quiescent current: 80 µA (EN=high)
- Meets automotive ISO7637 pulse 1 transient requirements with an additional TVS diode
- Package: 8-pin SOT-23 (2.90 mm x 1.60 mm)
Read more: LM74500-Q1 REVERSE POLARITY PROTECTION CONTROLLER
- What input voltage range does the LM74500-Q1 support?
The LM74500-Q1 supports an input range of 3.2 V to 65 V with a 3.9 V start-up. - Can the LM74500-Q1 handle negative supply voltages?
Yes, the device can withstand and protect loads from negative supply voltages down to -65 V. - Does the LM74500-Q1 block reverse current?
No, the LM74500-Q1 does not have reverse current blocking and is suitable for loads that can deliver energy back to the input. - What type of MOSFET is used with the LM74500-Q1?
The controller operates in conjunction with an external N-channel MOSFET using a charge pump gate drive. - What is the shutdown current when the enable pin is low?
With the enable pin low, the controller draws approximately 1 µA of current. - What is the typical operating quiescent current when enabled?
The typical operating quiescent current is 80 µA when EN is high. - Is the LM74500-Q1 qualified for automotive temperature ranges?
Yes, it is AEC-Q100 qualified for Grade 1 ambient temperatures from -40°C to +125°C. - Does the LM74500-Q1 meet ISO7637 transient requirements?
It meets automotive ISO7637 pulse 1 transient requirements when used with an additional TVS diode. - What package is the LM74500-Q1 available in?
The device is available in an 8-pin SOT-23 package sized 2.90 mm x 1.60 mm.
