SNOSDF5 September   2023 LM74700D-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
  8. 7 Typical Characteristics
  9. 8 Parameter Measurement Information
  10. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Input Voltage
      2. 9.3.2 Charge Pump
      3. 9.3.3 Gate Driver
      4. 9.3.4 Enable
    4. 9.4 Device Functional Modes
      1. 9.4.1 Shutdown Mode
      2. 9.4.2 Conduction Mode
        1. 9.4.2.1 Regulated Conduction Mode
        2. 9.4.2.2 Full Conduction Mode
        3. 9.4.2.3 Reverse Current Protection Mode
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Design Considerations
        2. 10.2.2.2 MOSFET Selection
        3. 10.2.2.3 Charge Pump VCAP, Input and Output Capacitance
      3. 10.2.3 Selection of TVS Diodes for 12-V Battery Protection Applications
      4. 10.2.4 Selection of TVS Diodes and MOSFET for 24-V Battery Protection Applications
      5. 10.2.5 Application Curves
      6. 10.2.6 OR-ing Application Configuration
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

The LM74700D-Q1 is an automotive AEC Q100 qualified 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 automotive battery systems. The 3.2-V input voltage support is particularly well designed 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 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 makes sure of zero DC reverse current flow. Fast response (< 0.75 µs) to reverse current blocking makes the device designed for systems with output voltage holdup requirements during ISO7637 pulse testing as well as power fail and input micro-short conditions.

The LM74700D-Q1 controller provides a charge pump gate drive for an external N-channel MOSFET. The high voltage rating of LM74700D-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.

Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2)
LM74700D-Q1 D (SOIC, 8) 5 mm × 3.9 mm
(1) For all available packages, see the orderable addendum at the end of the data sheet.
(2) The package size (length x width) is a nominal value and includes pins, where applicable.
GUID-20230809-SS0I-1ZK4-WWS3-LZWGMVCBWGPZ-low.svgTypical Application Schematic
GUID-37380961-E0F3-4F69-A269-120749C0907C-low.gifReverse Current Blocking During Input Short