SNOSDE6C December   2022  – August 2025 LM74900-Q1 , LM74910-Q1 , LM74910H-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  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
    7. 6.7 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Charge Pump
      2. 8.3.2 Dual Gate Control (DGATE, HGATE)
        1. 8.3.2.1 Reverse Battery Protection (A, C, DGATE)
        2. 8.3.2.2 Load Disconnect Switch Control (HGATE, OUT)
      3. 8.3.3 Overcurrent Protection (CS+, CS-, ILIM, IMON, TMR)
        1. 8.3.3.1 Pulse Overload Protection, Circuit Breaker
        2. 8.3.3.2 Overcurrent Protection With Latch-Off
        3. 8.3.3.3 Short Circuit Protection (ISCP)
        4. 8.3.3.4 Analog Current Monitor Output (IMON)
      4. 8.3.4 Undervoltage Protection, Overvoltage Protection, and Battery Voltage Sensing (UVLO, OV, SW)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Ultra Low IQ Shutdown (EN)
      2. 8.4.2 Low IQ SLEEP Mode (SLEEP)
  10. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical 12V Reverse Battery Protection Application
      1. 9.2.1 Design Requirements for 12V Battery Protection
      2. 9.2.2 Automotive Reverse Battery Protection
        1. 9.2.2.1 Input Transient Protection: ISO 7637-2 Pulse 1
        2. 9.2.2.2 AC Super Imposed Input Rectification: ISO 16750-2 and LV124 E-06
        3. 9.2.2.3 Input Micro-Short Protection: LV124 E-10
      3. 9.2.3 Detailed Design Procedure
        1. 9.2.3.1 Design Considerations
        2. 9.2.3.2 Charge Pump Capacitance VCAP
        3. 9.2.3.3 Input and Output Capacitance
        4. 9.2.3.4 Hold-Up Capacitance
        5. 9.2.3.5 Selection of Current Sense Resistor, RSNS
        6. 9.2.3.6 Selection of Scaling Resistor (RSET) and Short-Circuit Protection Setting Resistor (RSCP)
        7. 9.2.3.7 Overcurrent Limit (ILIM), Circuit Breaker Timer (TMR), and Current Monitoring Output (IMON) Selection
        8. 9.2.3.8 Overvoltage Protection and Battery Monitor
      4. 9.2.4 MOSFET Selection: Blocking MOSFET Q1
      5. 9.2.5 MOSFET Selection: Hot-Swap MOSFET Q2
      6. 9.2.6 TVS Selection
      7. 9.2.7 Application Curves
    3. 9.3 Addressing Automotive Input Reverse Battery Protection Topologies With LM749x0-Q1
    4. 9.4 Power Supply Recommendations
      1. 9.4.1 Transient Protection
      2. 9.4.2 TVS Selection for 12V Battery Systems
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RGE|24
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.2.2.1 Input Transient Protection: ISO 7637-2 Pulse 1

ISO 7637-2 Pulse 1 specifies negative transient immunity of electronic modules connected in parallel with an inductive load when the battery is disconnected. A typical pulse 1 specified in ISO 7637-2 starts with battery disconnection where supply voltage collapses to 0V followed by –150V 2ms applied with a source impedance of 10Ω at a slew rate of 1µs on the supply input. LM749x0-Q1 blocks reverse current and prevents the output voltage from swinging negative, protecting the rest of the electronic circuits from damage due to negative transient voltage. MOSFET Q1 is quickly turned off within 0.5µs by fast reverse comparator of LM749x0-Q1. A single bi-directional TVS is required at the input to clamp the negative transient pulse within the operating maximum voltage across cathode to anode of 85V and does not violate the MOSFET Q1 drain-source breakdown voltage rating.

ISO 7637-2 Pulse 1 performance of LM749x0-Q1 is shown in Figure 9-2.

LM74900-Q1 LM74910-Q1 LM74910H-Q1 ISO 7637-2 Pulse 1Figure 9-2 ISO 7637-2 Pulse 1