SNOSDD6 September   2021 LM74700-EP

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Voltage
      2. 8.3.2 Charge Pump
      3. 8.3.3 Gate Driver
      4. 8.3.4 Enable
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Conduction Mode
        1. 8.4.2.1 Regulated Conduction Mode
        2. 8.4.2.2 Full Conduction Mode
        3. 8.4.2.3 Reverse Current Protection Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Design Considerations
        2. 9.2.2.2 MOSFET Selection
        3. 9.2.2.3 Charge Pump VCAP, input and output capacitance
      3. 9.2.3 Selection of TVS Diodes for 12-V Battery Protection Applications
      4. 9.2.4 Selection of TVS Diodes and MOSFET for 24-V Battery Protection Applications
      5. 9.2.5 Application Curves
    3. 9.3 OR-ing Application Configuration
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

3 Description

The LM74700-EP is an 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 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 ensures zero DC reverse current flow. Fast response (< 0.75 µs) to Reverse Current Blocking makes the device suitable for systems with output voltage holdup requirements during power fail and input micro-short conditions.

The LM74700-EP controller provides a charge pump gate drive for an external N-channel MOSFET. The high voltage rating of LM74700-EP 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. The LM74700-EP is fully specified over the temperature range of TA = –55°C to +125°C.

Device Information(1)
PART NUMBERPACKAGEBODY SIZE (NOM)
LM74700-EPSOT-23 (8)2.90 mm × 1.60 mm
(1) For all available packages, see the orderable addendum at the end of the data sheet.
GUID-AB4AA10B-C298-49D1-B4DD-F23AAC88A5AE-low.gifTypical Application Schematic
GUID-FA0436F2-FDAA-4B41-AF77-53E540B68175-low.gifReverse Current Blocking During Input Short