SLVSG41 January   2022 TPS7H4003-SEP

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 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  VIN and Power VIN Pins (VIN and PVIN)
      2. 7.3.2  Voltage Reference
      3. 7.3.3  Adjusting the Output Voltage
      4. 7.3.4  Safe Start-Up Into Prebiased Outputs
      5. 7.3.5  Error Amplifier
      6. 7.3.6  Enable and Adjust UVLO
      7. 7.3.7  Adjustable Switching Frequency and Synchronization (SYNC)
        1. 7.3.7.1 Internal Oscillator Mode
        2. 7.3.7.2 External Synchronization Mode
        3. 7.3.7.3 Primary-Secondary Operation Mode
      8. 7.3.8  Soft-Start (SS/TR)
      9. 7.3.9  Power Good (PWRGD)
      10. 7.3.10 Sequencing
      11. 7.3.11 Output Overvoltage Protection (OVP)
      12. 7.3.12 Overcurrent Protection
        1. 7.3.12.1 High-Side MOSFET Overcurrent Protection
        2. 7.3.12.2 Low-Side MOSFET Overcurrent Protection
      13. 7.3.13 Thermal Shutdown
      14. 7.3.14 Turn-On Behavior
      15. 7.3.15 Slope Compensation
        1. 7.3.15.1 Slope Compensation Requirements
      16. 7.3.16 Small Signal Model for Frequency Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fixed-Frequency PWM Control
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Operating Frequency
        2. 8.2.2.2 Output Inductor Selection
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 Output Schottky Diode
        5. 8.2.2.5 Input Capacitor Selection
        6. 8.2.2.6 Soft-Start Capacitor Selection
        7. 8.2.2.7 Undervoltage Lockout (UVLO) Set Point
        8. 8.2.2.8 Output Voltage Feedback Resistor Selection
          1. 8.2.2.8.1 Minimum Output Voltage
        9. 8.2.2.9 Compensation Component Selection
      3. 8.2.3 Parallel Operation
      4. 8.2.4 Application Curve
  9. 9 Power Supply Recommendations
  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

8.2.2.7 Undervoltage Lockout (UVLO) Set Point

The UVLO can be adjusted using the external voltage divider network formed by R1 and R2. R1 is connected between VIN and the EN pin of the TPS7H4003-SEP and R2 is connected between EN and GND. The UVLO has two thresholds, one for power up when the input voltage is rising and one for power down or brown outs when the input voltage is falling. For the example design, the supply should turn on and start switching once the input voltage increases above selected voltage (UVLO start or enable). After the regulator starts switching, it should continue to do so until the input voltage falls below (UVLO stop or disable) voltage. Equation 2 and Equation 3 can be used to calculate the values for the upper and lower resistor values. For the stop voltages specified in Table 8-1, the nearest standard resistor value for R1 is 10 kΩ and for R2 is 3.4 kΩ.