SLVSC68A June   2015  – June 2015 TPS62745 , TPS627451

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Typical Application Schematic
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Characteristics
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 DCS-Control™
      2. 8.3.2 Enable / Shutdown
      3. 8.3.3 Power Good Output (PG)
      4. 8.3.4 Output Voltage Selection (VSEL1 - 4)
      5. 8.3.5 Input Voltage Switch
    4. 8.4 Device Functional Modes
      1. 8.4.1 Soft Start
    5. 8.5 VOUT Discharge
    6. 8.6 Internal Current Limit
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Output Voltage Selection (VSEL1 - 4)
        2. 9.2.2.2 Output Filter Design (Inductor and Output Capacitor)
        3. 9.2.2.3 Inductor Selection
        4. 9.2.2.4 DC/DC Output Capacitor Selection
        5. 9.2.2.5 Input Capacitor Selection
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 TPS62745 Set to a Fixed Voltage of 3.3 V
        1. 9.3.1.1 Design Requirements
        2. 9.3.1.2 Detailed Design Procedure
        3. 9.3.1.3 Application Curves
      2. 9.3.2 Dynamic Voltage Change on TPS62745
        1. 9.3.2.1 Design Requirements
        2. 9.3.2.2 Detailed Design Procedure
        3. 9.3.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Related Links
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

11 Layout

11.1 Layout Guidelines

As for all switching power supplies, the layout is an important step in the design. Especially RF designs demand careful attention to the PCB layout. Care must be taken in board layout to get the specified performance. If the layout is not carefully done, the regulator could show poor line and/or load regulation, stability issues as well as EMI problems and interference with RF circuits. It is critical to provide a low inductance, impedance ground path. Therefore, use wide and short traces for the main current paths. The input capacitor should be placed as close as possible to the IC pins as well as the inductor and output capacitor. Use a common power GND node and a different node for the signal GND to minimize the effects of ground noise. Keep the common path to the GND pin, which returns the small signal components and the high current of the output capacitors as short as possible to avoid ground noise. The VOUT line should be connected to the output capacitor and routed away from noisy components and traces (e.g. SW line).

11.2 Layout Example

TPS62745 TPS627451 TPS62745layout.gifFigure 40. Recommended PCB Layout