SLVSD26B April   2016  – April 2021 TPS54202

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. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fixed-Frequency PWM Control
      2. 7.3.2  Pulse Skip Mode
      3. 7.3.3  Error Amplifier
      4. 7.3.4  Slope Compensation and Output Current
      5. 7.3.5  Enable and Adjusting Under Voltage Lockout
      6. 7.3.6  Safe Startup into Pre-Biased Outputs
      7. 7.3.7  Voltage Reference
      8. 7.3.8  Adjusting Output Voltage
      9. 7.3.9  Internal Soft-Start
      10. 7.3.10 Bootstrap Voltage (BOOT)
      11. 7.3.11 Overcurrent Protection
        1. 7.3.11.1 High-Side MOSFET Overcurrent Protection
        2. 7.3.11.2 Low-Side MOSFET Overcurrent Protection
      12. 7.3.12 Spread Spectrum
      13. 7.3.13 Output Overvoltage Protection (OVP)
      14. 7.3.14 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation
      2. 7.4.2 Eco-mode Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 TPS54202 8-V to 28-V Input, 5-V Output Converter
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Input Capacitor Selection
        2. 8.2.3.2 Bootstrap Capacitor Selection
        3. 8.2.3.3 Output Voltage Set Point
        4. 8.2.3.4 Undervoltage Lockout Set Point
        5. 8.2.3.5 Output Filter Components
          1. 8.2.3.5.1 Inductor Selection
          2. 8.2.3.5.2 Output Capacitor Selection
          3. 8.2.3.5.3 Feed-Forward Capacitor
      4. 8.2.4 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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    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

Package Options

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

7.1 Overview

The TPS54202 device is a 28-V, 2-A, synchronous step-down (buck) converter with two integrated n-channel MOSFETs. To improve performance during line and load transients the device implements a constant-frequency, peak current mode control which reduces output capacitance. The optimized internal compensation network minimizes the external component counts and simplifies the control loop design.

The switching frequency is fixed to 500 kHz.

The device begins switching at VIN equal to 4.5 V. The operating current is 45 μA typically when not switching and under no load. When the device is disabled, the supply current is 2 µA typically.

The integrated 148-mΩ high-side MOSFET and 78-mΩ allow for high efficiency power supply designs with continuous output currents up to 2 A.

The device reduces the external component count by integrating the boot recharge diode. The bias voltage for the integrated high-side MOSFET is supplied by an external capacitor on the BOOT to PH pins. The boot capacitor voltage is monitored by an UVLO circuit and will turn the high-side MOSFET off when the voltage falls below a preset threshold of 2.1 V typically.

The device minimizes excessive output overvoltage transients by taking advantage of the overvoltage comparator. When the regulated output voltage is greater than 108% of the nominal voltage, the overvoltage comparator is activated, and the high-side MOSFET is turned off and masked from turning on until the output voltage is lower than 104%.

The device has internal 5-ms soft-start time to minimize inrush currents.