Overview
The LM74500-Q1 is an automotive AEC-Q100 qualified controller designed by Texas Instruments to provide low-loss reverse polarity protection. It operates in conjunction with an external N-channel MOSFET, making it suitable for various automotive and industrial applications. The controller supports a wide input voltage range of 3.2 V to 65 V, which is particularly beneficial for severe cold crank requirements in automotive systems. It can withstand and protect loads from negative supply voltages down to –65 V, making it an essential component for ensuring system reliability and safety.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Temperature Range | –40 to 125 | °C |
| Input Voltage Range | 3.2 to 65 | V |
| Input Reverse Voltage Rating | –65 | V |
| Startup Voltage | 3.9 | V |
| Shutdown Current (EN=Low) | 1 | µA |
| Quiescent Current (EN=High) | 80 | µA |
| Package Type | 8-pin SOT-23 | |
| Package Dimensions | 2.90 mm × 1.60 mm | |
| Junction-to-Ambient Thermal Resistance | 133.8 | °C/W |
Key Features
- AEC-Q100 qualified with device temperature grade 1: –40°C to +125°C ambient operating temperature range.
- Device HBM ESD classification level 2 and CDM ESD classification level C4B.
- Charge pump for external N-channel MOSFET with a maximum gate drive voltage of approximately 15 V.
- Enable pin feature allowing the controller to be placed in shutdown mode, drawing approximately 1 µA of current.
- Meets automotive ISO7637 pulse 1 transient requirements with additional TVS Diode.
- Suitable for input reverse polarity protection of loads that can potentially deliver energy back to the input supply.
- Excellent severe cold crank performance, keeping the external FET fully enhanced even when input voltage falls to 3.2 V.
Applications
- Automotive body electronics and lighting.
- Automotive infotainment systems, including digital clusters and head units.
- Automotive USB Hubs.
- Industrial factory automation, such as PLCs.
Q & A
- What is the primary function of the LM74500-Q1?
The LM74500-Q1 is designed to provide low-loss reverse polarity protection in conjunction with an external N-channel MOSFET.
- What is the operating temperature range of the LM74500-Q1?
The operating temperature range is –40°C to +125°C.
- What is the input voltage range of the LM74500-Q1?
The input voltage range is 3.2 V to 65 V.
- How does the LM74500-Q1 handle negative voltage transients?
The device can withstand and protect loads from negative supply voltages down to –65 V.
- What is the purpose of the charge pump in the LM74500-Q1?
The charge pump is used to drive the external N-channel MOSFET to a maximum gate drive voltage of approximately 15 V.
- How does the enable pin function in the LM74500-Q1?
The enable pin allows the controller to be placed in shutdown mode, drawing approximately 1 µA of current when disabled.
- Does the LM74500-Q1 meet any specific automotive standards?
Yes, it meets automotive ISO7637 pulse 1 transient requirements with additional TVS Diode.
- What are the typical applications of the LM74500-Q1?
It is used in automotive body electronics, infotainment systems, USB hubs, and industrial factory automation.
- How does the LM74500-Q1 perform during severe cold crank conditions?
The LM74500-Q1 keeps the external FET fully enhanced even when the input voltage falls to 3.2 V, providing excellent cold crank performance.
- What is the package type and dimensions of the LM74500-Q1?
The LM74500-Q1 is available in an 8-pin SOT-23 package with dimensions of 2.90 mm × 1.60 mm.
