SLVSFS6A May   2021  – September 2021 TPS629210-Q1

ADVANCE INFORMATION  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  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
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Mode Selection and Device Configuration (MODE/S-CONF Pin)
      2. 8.3.2 Adjustable VO Operation (External Voltage Divider)
      3. 8.3.3 Settable VO Operation (VSET and Internal Voltage Divider)
      4. 8.3.4 Smart Enable with Precise Threshold
      5. 8.3.5 Power Good (PG)
      6. 8.3.6 Undervoltage Lockout (UVLO)
      7. 8.3.7 Current Limit and Short Circuit Protection
      8. 8.3.8 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Forced Pulse Width Modulation (PWM) Operation
      2. 8.4.2 AEE (Automatic Efficiency Enhancement)
      3. 8.4.3 Power Save Mode Operation (Auto PFM/PWM)
      4. 8.4.4 100% Duty-Cycle Operation
      5. 8.4.5 Output Discharge Function
      6. 8.4.6 Starting into a Pre-Biased Load
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 External Component Selection
        1. 9.1.1.1 Programming the Output Voltage
        2. 9.1.1.2 Inductor Selection
        3. 9.1.1.3 Capacitor Selection
          1. 9.1.1.3.1 Output Capacitor
          2. 9.1.1.3.2 Input Capacitor
        4. 9.1.1.4 Output Filter and Loop Stability
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
      1. 11.2.1 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support 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

Output Filter and Loop Stability

The TPS629210-Q1 is internally compensated to be stable with L-C filter combinations corresponding to a corner frequency to be calculated with Equation 17:

Equation 17. GUID-885EAF52-DD0C-4083-A83E-7604F20F903B-low.gif

The LC output filters inductance and capacitance have to be considered together, creating a double pole, responsible for the corner frequency of the converter. Table 9-3 can be used to simplify the output filter component selection.

Proven nominal values for inductance and ceramic capacitance are given in Table 9-3 and are recommended for use. Different values can work, but care has to be taken on the loop stability which is affected. More information including a detailed LC stability matrix can be found in Optimizing the TPS62130/40/50/60 Output Filter Application Report.

Table 9-3 Recommended LC Output Filter Combinations
4.7 µF(2) 10 µF(2) 22 µF(2) 47 µF(2) 100 µF(2) 200 µF(2)
2.2 µH (1) (3)
4.7 µH
This LC combination is the standard value and recommended for most applications.
These values are nominal values, and the effective capcitance was considered to vary by +20% and –50%.
Output capacitance needs to have a ESR of ≥ 10 mΩ for stable operation

Although the TPS629210-Q1 is stable without the pole and zero being in a particular location, an external feedforward capacitor can also be added to adjust their location based on the specific needs of the application. This can provide better performance in Power Save mode, improved transient response, or both.

A more detailed discussion on the optimization for stability versus transient response can be found in the Optimizing Transient Response of Internally Compensated DC-DC Converters Application Report and Feedforward Capacitor to Improve Stability and Bandwidth of TPS621/821-Family Application Report.