SLVSFP4B August   2020  – March 2021 TPS62912 , TPS62913

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  Smart Config (S-CONF)
      2. 7.3.2  Device Enable (EN/SYNC)
      3. 7.3.3  Device Synchronization (EN/SYNC)
      4. 7.3.4  Spread Spectrum Modulation
      5. 7.3.5  Output Discharge
      6. 7.3.6  Undervoltage Lockout (UVLO)
      7. 7.3.7  Power-Good Output
      8. 7.3.8  Noise Reduction and Soft-Start Capacitor (NR/SS)
      9. 7.3.9  Current Limit and Short Circuit Protection
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fixed Frequency Pulse Width Modulation
      2. 7.4.2 Low Duty Cycle Operation
      3. 7.4.3 High Duty Cycle Operation (100% Duty Cycle)
      4. 7.4.4 Second Stage L-C Filter Compensation (Optional)
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 External Component Selection
          1. 8.2.2.2.1 Switching Frequency Selection
          2. 8.2.2.2.2 Inductor Selection for the First L-C Filter
          3. 8.2.2.2.3 Output Capacitor Selection
          4. 8.2.2.2.4 Ferrite Bead Selection for Second L-C Filter
          5. 8.2.2.2.5 Input Capacitor Selection
          6. 8.2.2.2.6 Setting the Output Voltage
          7. 8.2.2.2.7 NR/SS Capacitor Selection
      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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    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

10.1 Layout Guidelines

A proper layout is critical for the operation of any switched mode power supply, especially at high switching frequencies. Therefore, the PCB layout of the TPS6291x demands careful attention to ensure best performance. A poor layout can lead to issues like bad line and load regulation, instability, increased EMI radiation, and noise sensitivity. Refer to the Five Steps to a Great PCB Layout for a Step-Down Converter Technical Brief for a detailed discussion of general best practices. Specific recommendations for the device are listed below.

  • The input capacitor or capacitors should be placed as close as possible to the VIN and PGND pins of the device. This is the most critical component placement. Route the input capacitors directly to the VIN and PGND pins avoiding vias.
  • Place the inductor close to the SW pin. Minimize the copper area at the switch node.
  • Place the output capacitor ground close to the PGND pin and route it directly avoiding vias. Minimize the length of the connection from the inductor to the output capacitor.
  • Connect the VO pin directly to the first output capacitor, COUT.
  • Sensitive traces, such as the connections to the NR/SS, VO, and FB pins need to be connected with short traces and be routed away from any noise source, such as the SW pin.
  • Connect the PSNS pin directly to the system GND plane with a via.
  • Place the second L-C filter, Lf and Cf, near the load to reduce any radiated coupling around the second L-C filter
  • Avoid placing the ferrite bead in the keep out region as shown in Figure 10-2
  • Place the FB resistors, R1 and R2, close to the FB pin and route the VOUT connection from R1 to the load as a remote sense trace. If a second L-C filter is used, this connection should be made after Lf.
  • The recommended layout is implemented on the EVM and shown in its User's Guide, TPS6291xEVM-077 User's Guide, as well as in Figure 10-2.