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

100% Duty-Cycle Operation

The duty cycle of the buck converter operated in PWM mode is given in Equation 11.

Equation 11. GUID-20210112-CA0I-0BT3-NMWK-5L8FMQNJPWJQ-low.gif

The duty cycle increases as the input voltage comes close to the output voltage and the off time of the high-side switch gets smaller. When the minimum off time of typically 80 ns is reached, the TPS629210-Q1 scales down its switching frequency while it approaches 100% mode. In 100% mode, it keeps the high-side switch on continuously as long as the output voltage is below the internal set point. This allows the conversion of small input to output voltage differences. For example, getting the longest operation time of battery-powered applications. In 100% duty cycle mode, the low-side FET is switched off.

The minimum input voltage to maintain output voltage regulation, depending on the load current and the output voltage level, can be calculated as:

Equation 12. GUID-0F1BED33-FB2E-403B-ACCB-46851B313FFE-low.gif

where:

  • IOUT is the output current
  • RDS(on) is the on-state resistance of the high-side FET
  • RL is the DC resistance of the inductor used