SLVSFQ0A October   2020  – June 2021 TPS54J061

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  Enable and Internal LDO
      2. 7.3.2  Split Rail and External LDO
      3. 7.3.3  Output Voltage Setting
      4. 7.3.4  Soft Start and Output-Voltage Tracking
      5. 7.3.5  Frequency and Operation Mode Selection
      6. 7.3.6  D-CAP3 Control
      7. 7.3.7  Current Sense and Positive Overcurrent Protection
      8. 7.3.8  Low-side FET Negative Current Limit
      9. 7.3.9  Power Good
      10. 7.3.10 Overvoltage and Undervoltage Protection
      11. 7.3.11 Out-Of-Bounds Operation (OOB)
      12. 7.3.12 Output Voltage Discharge
      13. 7.3.13 UVLO Protection
      14. 7.3.14 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Auto-Skip Eco-Mode Light Load Operation
      2. 7.4.2 Forced Continuous-Conduction Mode
      3. 7.4.3 Pre-Bias Start-up
  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  Choose the Switching Frequency and Operation Mode (MODE Pin)
        2. 8.2.2.2  Choose the Output Inductor (L)
        3. 8.2.2.3  Set the Current Limit (TRIP)
        4. 8.2.2.4  Choose the Output Capacitors (COUT)
        5. 8.2.2.5  Choose the Input Capacitors (CIN)
        6. 8.2.2.6  Feedback Network (FB Pin)
        7. 8.2.2.7  Soft Start Capacitor (SS/REFIN Pin)
        8. 8.2.2.8  EN Pin Resistor Divider
        9. 8.2.2.9  VCC Bypass Capacitor
        10. 8.2.2.10 BOOT Capacitor
        11. 8.2.2.11 Series BOOT Resistor and RC Snubber
        12. 8.2.2.12 PGOOD Pullup Resistor
      3. 8.2.3 Application Curves
  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 Support Resources
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Trademarks
    5. 11.5 Glossary
    6. 11.6 Electrostatic Discharge Caution
  12. 12Mechanical, Packaging, and Ordering Information

Package Options

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

7.3.10 Overvoltage and Undervoltage Protection

The TPS54J061 monitors the FB voltage to detect overvoltage and undervoltage. When the FB voltage becomes lower than 80% of the VINTREF voltage, the UVP comparator detects and an internal UVP delay counter begins counting. After the 64-µs UVP delay time, the device latches OFF both high-side and low-side FETs drivers. The UVP function enables after the soft-start period is complete.

When the FB voltage becomes higher than 116% of the VINTREF voltage, the OVP comparator detects and the circuit latches OFF the high-side MOSFET driver and turns on the low-side MOSFET until reaching a negative current limit INOCL. Upon reaching the negative current limit, the low-side FET is turned off, and the high-side FET is turned on again for the on-time determined by VIN, VOUT and fSW. The device operates in this cycle until the output voltage is pulled down under the UVP threshold voltage for 64 µs. After the 64-µs UVP delay time, both high-side and low-side FET latch off. The fault is cleared with a reset of the input voltage or by re-toggling the EN pin.

During the UVP delay time, if output voltage becomes higher than UV threshold, thus is not qualified for UV event, the timer will be reset to zero. When the output voltage triggers UV threshold again, the UVP delay timer restarts.