SLVSAD5A July   2010  – August 2015 TPS62120 , TPS62122

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  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 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 Undervoltage Lockout
      2. 8.3.2 Enable and Shutdown
      3. 8.3.3 Power Good Output
      4. 8.3.4 SGND Open-Drain Output
      5. 8.3.5 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Soft Start
      2. 8.4.2 Main Control Loop
      3. 8.4.3 100% Duty Cycle Low-Dropout Operation
      4. 8.4.4 Short-Circuit Protection
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 TPS62120 With Open-Drain Output
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Output Voltage Setting
          2. 9.2.1.2.2 Output Filter Design (Inductor and Output Capacitor)
          3. 9.2.1.2.3 Inductor Selection
          4. 9.2.1.2.4 Output Capacitor Selection
          5. 9.2.1.2.5 Input Capacitor Selection
          6. 9.2.1.2.6 Checking Loop Stability
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Standard Circuit for TPS62122
    3. 9.3 System Examples
      1. 9.3.1 TPS62120 1.8-V Output Voltage Configuration
      2. 9.3.2 TPS62120 3.06-V Output Voltage Configuration
      3. 9.3.3 TPS62122 2.0-V Output Voltage Configuration
      4. 9.3.4 TPS62120 1.8-V VOUT Configuration Powered From a High-Impedance Source
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Examples
  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

11 Layout

11.1 Layout Guidelines

As for all switching power supplies, the layout is an important step in the design. Proper function of the device demands careful attention to 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. 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 FB divider network and the VOUT line must be connected to the output capacitor. The VOUT pin of the converter should be connected through a short trace to the output capacitor. The FB line must be routed away from noisy components and traces (for example, SW line).

11.2 Layout Examples

TPS62120 TPS62122 PCB_DCN_layout_lvsad5.gifFigure 41. PCB Layout - DCN Package
TPS62120 TPS62122 PCB_DRV_layout_lvsad5.gifFigure 42. PCB Layout - DRV Package