SLVSDS9E July   2018  – August 2021 TPS63805 , TPS63806 , TPS63807

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Control Loop Description
      2. 9.3.2  Precise Device Enable: Threshold- or Delayed Enable
      3. 9.3.3  Mode Selection (PFM/PWM)
      4. 9.3.4  Undervoltage Lockout (UVLO)
      5. 9.3.5  Soft Start
      6. 9.3.6  Adjustable Output Voltage
      7. 9.3.7  Overtemperature Protection - Thermal Shutdown
      8. 9.3.8  Input Overvoltage - Reverse-Boost Protection (IVP)
      9. 9.3.9  Output Overvoltage Protection (OVP)
      10. 9.3.10 Power-Good Indicator
    4. 9.4 Device Functional Modes
      1. 9.4.1 Peak-Current Mode Architecture
        1. 9.4.1.1 Reverse Current Operation, Negative Current
        2. 9.4.1.2 Boost Operation
        3. 9.4.1.3 Buck-Boost Operation
        4. 9.4.1.4 Buck Operation
      2. 9.4.2 Power Save Mode Operation
        1. 9.4.2.1 Current Limit Operation
  10. 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 Custom Design With WEBENCH® Tools
        2. 10.2.2.2 Inductor Selection
        3. 10.2.2.3 Output Capacitor Selection
        4. 10.2.2.4 Input Capacitor Selection
        5. 10.2.2.5 Setting The Output Voltage
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
      2. 13.1.2 Development Support
        1. 13.1.2.1 Custom Design With WEBENCH® Tools
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

9.4.2 Power Save Mode Operation

Besides continuos conduction mode (PWM), the TPS63805, TPS63806, and TPS63807 feature power safe mode (PFM) operation to achieve high efficiency at light load currents. This is implemented by pausing the switching operation, depending on the load current.

The skip comparator manages the switching or pause operation. It compares the current demand signal from the voltage loop, IREF, with the skip threshold, ISKIP, as shown in Figure 9-1. If the current demand is lower than the skip value, the comparator pauses switching operation. If the current demand goes higher (due to falling VO), the comparator activates the current loop and allows switching according to the loop behavior. Whenever the current loop has risen VO by bringing charge to the output, the voltage loop output, IREF (respectively VEA), decreases. When IREF falls below ISKIP-hysteresis, it automatically pauses again.

GUID-1EC7D6F2-D9FB-43CA-922C-85AAEF2CA61A-low.gifFigure 9-10 Power Safe Mode Operation Curves