Overview
The LM74502HQDDFRQ1, produced by Texas Instruments, is an automotive-grade reverse polarity protection controller designed to work in conjunction with external back-to-back connected N-channel MOSFETs. This controller is AEC-Q100 qualified and operates over a wide input supply range of 3.2 V to 65 V, making it suitable for various DC bus voltages in automotive systems, including 12-V, 24-V, and 48-V battery systems. It provides an efficient and fast reverse polarity protection and load disconnect solution, ensuring the protection of loads from negative supply voltages down to -65 V.
Key Specifications
| Attribute | Value |
|---|---|
| Package | SOT-23-THN (DDF), 8 pins |
| Operating Temperature Range | -40°C to +125°C |
| Input Supply Voltage Range | 3.2 V to 65 V |
| Input Reverse Voltage Rating | -65 V |
| Gate Drive Variants | LM74502-Q1: 60 μA peak, LM74502H-Q1: 11 mA peak |
| Shutdown Current (EN/UVLO = Low) | 1 μA |
| Operating Quiescent Current (EN/UVLO = High) | 45 μA typical |
| Peak Gate Sink Capacity | 2 A |
| ESD Classification | HBM Level 2, CDM Level C4B |
Key Features
- AEC-Q100 qualified with an operating temperature range of -40°C to +125°C.
- Integrated charge pump to drive external back-to-back connected N-channel MOSFETs.
- Adjustable overvoltage and undervoltage protection using a resistor divider.
- Low shutdown current of 1 μA when EN/UVLO pin is low.
- Typical operating quiescent current of 45 μA when EN/UVLO pin is high.
- Gate drive variants: LM74502-Q1 with 60 μA peak gate drive strength and LM74502H-Q1 with 11 mA peak gate drive strength.
- Meets automotive ISO7637 pulse 1 transient requirements with additional TVS diode.
- Inrush current control scheme available for applications with large capacitive loads.
Applications
The LM74502HQDDFRQ1 is primarily used in automotive systems for reverse polarity protection and load disconnect solutions. It is suitable for protecting 12-V, 24-V, and 48-V automotive battery-powered ECUs from negative supply voltages and overvoltage conditions. The device can be used in various automotive applications, including:
- Reverse polarity protection circuits.
- Load switch applications requiring fast turn-on.
- Automotive battery management systems.
- Protection against ISO7637 pulse 1 transients.
Q & A
- What is the operating temperature range of the LM74502HQDDFRQ1?
The operating temperature range is -40°C to +125°C.
- What is the input supply voltage range of the LM74502HQDDFRQ1?
The input supply voltage range is 3.2 V to 65 V.
- How does the LM74502HQDDFRQ1 protect against reverse polarity?
The device uses an integrated charge pump to drive external back-to-back connected N-channel MOSFETs, providing reverse polarity protection and load disconnect functionality.
- What are the gate drive variants available for the LM74502HQDDFRQ1?
The LM74502-Q1 has a typical peak gate drive strength of 60 μA, while the LM74502H-Q1 has a typical peak gate drive strength of 11 mA.
- How does the LM74502HQDDFRQ1 handle overvoltage protection?
The device features adjustable overvoltage protection using a resistor divider connected to the OV pin.
- What is the shutdown current of the LM74502HQDDFRQ1 when the EN/UVLO pin is low?
The shutdown current is approximately 1 μA when the EN/UVLO pin is low.
- What are the ESD classification levels for the LM74502HQDDFRQ1?
The device has an HBM ESD classification level 2 and CDM ESD classification level C4B.
- How does the LM74502HQDDFRQ1 meet automotive ISO7637 requirements?
The device meets automotive ISO7637 pulse 1 transient requirements with the use of additional TVS diodes.
- What is the typical operating quiescent current of the LM74502HQDDFRQ1?
The typical operating quiescent current is 45 μA when the EN/UVLO pin is high.
- What type of MOSFETs should be used with the LM74502HQDDFRQ1?
The device should be used with N-channel MOSFETs, with recommendations for MOSFETs having a voltage rating up to 60 V and a minimum VGS rating of 15 V).
