SNOSDC0A October   2020  – December 2020 LM7310

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 Timing Requirements
    7. 6.7 Switching Characteristics
    8.     14
    9. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input Reverse Polarity Protection
      2. 7.3.2 Undervoltage Protection (UVLO & UVP)
      3. 7.3.3 Overvoltage Lockout (OVLO)
      4. 7.3.4 Inrush Current control and Fast-trip
        1. 7.3.4.1 Slew Rate (dVdt) and Inrush Current Control
        2. 7.3.4.2 Fast-Trip During Steady State
      5. 7.3.5 Analog Load Current Monitor Output
      6. 7.3.6 Reverse Current Protection
      7. 7.3.7 Overtemperature Protection (OTP)
      8. 7.3.8 Fault Response
      9. 7.3.9 Power Good Indication (PG)
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Single Device, Self-Controlled
      1. 8.2.1 Typical Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Setting Undervoltage and Overvoltage Thresholds
          2. 8.2.1.2.2 Setting Output Voltage Rise Time (tR)
          3. 8.2.1.2.3 Setting Power Good Assertion Threshold
          4. 8.2.1.2.4 Setting Analog Current Monitor Voltage (IMON) Range
        3. 8.2.1.3 Application Curves
    3. 8.3 Active ORing
    4. 8.4 Priority Power MUXing
    5. 8.5 USB PD Port Protection
    6. 8.6 Parallel Operation
  9. 9 Power Supply Recommendations
    1. 9.1 Transient Protection
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

10.1 Layout Guidelines

  • For all applications, a ceramic decoupling capacitor of 0.1 μF or greater is recommended between the IN terminal and GND terminal.
  • The optimal placement of the decoupling capacitor is closest to the IN pin and GND terminals of the device. Care must be taken to minimize the loop area formed by the bypass-capacitor connection, the IN pin and the GND terminal of the IC.
  • High current-carrying power-path connections must be as short as possible and must be sized to carry at least twice the full-load current.
  • The GND terminal of the device must be tied to the PCB ground plane at the terminal of the IC with the shortest possible trace. The PCB ground must be a copper plane or island on the board. It's recommended to have a separate ground plane island for the device. This plane doesn't carry any high currents and serves as a quiet ground reference for all the critical analog signals of the device. The device ground plane should be connected to the system power ground plane using a star connection.
  • The IN and OUT pins are used for heat dissipation. Connect to as much copper area on top and bottom PCB layers using as possible with thermal vias. The vias under the device also help to minimize the voltage gradient accross the IN and OUT pads and distribute current unformly through the device, which is essential to achieve the best on-resistance and current sense accuracy.
  • Locate the following support components close to their connection pins:
    • RIMON
    • CdVdT
    • Resistors for the EN/UVLO, OVLO and PGTH pins
  • Connect the other end of the component to the GND pin of the device with shortest trace length. The trace routing for the CdVdt must be as short as possible to reduce parasitic effects on the soft-start timing. These traces must not have any coupling to switching signals on the board.
  • Protection devices such as TVS, snubbers, capacitors, or diodes must be placed physically close to the device they are intended to protect. These protection devices must be routed with short traces to reduce inductance. For example, a protection Schottky diode is recommended between OUT terminal and GND terminal to address negative transients due to switching of inductive loads. It's also recommended to add a ceramic decoupling capacitor of 1 μF or greater between OUT and GND. These components must be physically close to the OUT pins. Care must be taken to minimize the loop area formed by the Schottky diode/bypass-capacitor connection, the OUT pin and the GND terminal of the IC.