SLUSC70D March   2016  – July 2017 TPS548D22

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 40-A FET
      2. 7.3.2 On-Resistance
      3. 7.3.3 Package Size, Efficiency and Thermal Performance
      4. 7.3.4 Soft-Start Operation
      5. 7.3.5 VDD Supply Undervoltage Lockout (UVLO) Protection
      6. 7.3.6 EN_UVLO Pin Functionality
      7. 7.3.7 Fault Protections
        1. 7.3.7.1 Current Limit (ILIM) Functionality
        2. 7.3.7.2 VDD Undervoltage Lockout (UVLO)
        3. 7.3.7.3 Overvoltage Protection (OVP) and Undervoltage Protection (UVP)
        4. 7.3.7.4 Out-of-Bounds Operation
        5. 7.3.7.5 Overtemperature Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 DCAP3 Control Topology
      2. 7.4.2 DCAP Control Topology
    5. 7.5 Programming
      1. 7.5.1 Programmable Pin-Strap Settings
        1. 7.5.1.1 Frequency Selection (FSEL) Pin
        2. 7.5.1.2 VSEL Pin
        3. 7.5.1.3 DCAP3 Control and Mode Selection
          1. 7.5.1.3.1 Application Workaround to Support 4-ms and 8-ms SS Settings
      2. 7.5.2 Programmable Analog Configurations
        1. 7.5.2.1 RSP/RSN Remote Sensing Functionality
          1. 7.5.2.1.1 Output Differential Remote Sensing Amplifier
        2. 7.5.2.2 Power Good (PGOOD Pin) Functionality
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 TPS548D22 1.5-V to 16-V Input, 1-V Output, 40-A Converter
      2. 8.2.2 Design Requirements
      3. 8.2.3 Design Procedure
        1. 8.2.3.1  Switching Frequency Selection
        2. 8.2.3.2  Inductor Selection
        3. 8.2.3.3  Output Capacitor Selection
          1. 8.2.3.3.1 Minimum Output Capacitance to Ensure Stability
          2. 8.2.3.3.2 Response to a Load Transient
          3. 8.2.3.3.3 Output Voltage Ripple
        4. 8.2.3.4  Input Capacitor Selection
        5. 8.2.3.5  Bootstrap Capacitor Selection
        6. 8.2.3.6  BP Pin
        7. 8.2.3.7  R-C Snubber and VIN Pin High-Frequency Bypass
        8. 8.2.3.8  Optimize Reference Voltage (VSEL)
        9. 8.2.3.9  MODE Pin Selection
        10. 8.2.3.10 Overcurrent Limit Design.
      4. 8.2.4 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
      1. 10.2.1 Mounting and Thermal Profile Recommendation
  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 Community 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

7.5.1.3.1 Application Workaround to Support 4-ms and 8-ms SS Settings

In order to properly design for 4-ms and 8-ms SS settings, additional application consideration is needed. The recommended application workaround to support the 4-ms and 8-ms soft-start settings is to ensure sufficient time delay between the VDD and EN_UVLO signals. The minimum delay between the rising maximum VDD_UVLO level and the minimum turnon threshold of EN_UVLO is at least TDELAY_MIN.

Equation 1. TDELAY_MIN = K × VREF

where

  • K = 9 ms/V for SS setting of 4 ms
  • K = 18 ms/V for SS setting of 8 ms
  • VREF is the internal reference voltage programmed by VSEL pin strap

For example, if SS setting is 4 ms and VREF = 1 V, program the minimum delay at least 9 ms; if SS setting is 8 ms, the minimum delay should be programmed at least 18 ms. See Figure 16 and Figure 17 for detailed timing requirement.

TPS548D22 scopeshot-01-workaround.pngFigure 16. Proper Sequencing of VDD and EN_UVLO to Support the use of 4-ms SS Setting
TPS548D22 workaround-timing-diagram-snvsau8.gifFigure 17. Minimum Delay Between VDD and EN_UVLO to Support the use of 4-ms and 8-ms SS settings

The workaround/consideration described previously is not required for SS settings of 1 ms and 2 ms.