SLVSCM3B january   2015  – august 2023 TPS62065-Q1 , TPS62067-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 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.     Typical Characteristics
  9. 8 Parameter Measurement Information
  10. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Mode Selection (TPS62065-Q1) and Forced PWM Mode (TPS62067A-Q1)
      2. 9.3.2 Power Good (PG, TPS62067x-Q1)
      3. 9.3.3 Enable
      4. 9.3.4 Shutdown and Output Discharge
      5. 9.3.5 Soft Start
      6. 9.3.6 Undervoltage Lockout (UVLO)
      7. 9.3.7 Internal Current Limit and Foldback Current Limit For Short-Circuit Protection
      8. 9.3.8 Clock Dithering
      9. 9.3.9 Thermal Shutdown
    4. 9.4 Device Functional Modes
      1. 9.4.1 Power Save Mode
        1. 9.4.1.1 Dynamic Voltage Positioning
        2. 9.4.1.2 100% Duty-Cycle Low-Dropout Operation
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Output Voltage Setting
        2. 10.2.2.2 Output Filter Design (Inductor And Output Capacitor)
          1. 10.2.2.2.1 Inductor Selection
          2. 10.2.2.2.2 Output Capacitor Selection
          3. 10.2.2.2.3 Input Capacitor Selection
        3. 10.2.2.3 Checking Loop Stability
      3. 10.2.3 Application Curves
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    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
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

10.2.2.3 Checking Loop Stability

The first step of circuit and stability evaluation is to look from a steady-state perspective at the following signal:

  • Switching node, SW
  • Inductor current, IL
  • Output ripple voltage, VOUT(AC)

These are the basic signals that must be measured when evaluating a switching converter. When the switching waveform shows large duty cycle jitter or the output voltage or inductor current shows oscillations, the regulation loop can be unstable. This is often a result of board layout, wrong L-C output filter combinations, or both. As a next step in the evaluation of the regulation loop, test the load transient response. The results are most easily interpreted when the device operates in PWM mode at medium to high load currents.

During this recovery time, VOUT can be monitored for settling time, overshoot, or ringing; that helps evaluate stability of the converter. Without any ringing, the loop has usually more than 45° of phase margin.