SLVSDZ7A September   2017  – December 2017 TPS62097-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      1.8-V Output, Typical Application
      2.      1.8-V Output, Efficiency, MODE = Open
  4. 4 Revision History
  5. 5 Terminal Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommend 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. 7.3.1 100% Duty Cycle Mode
      2. 7.3.2 Switch Current Limit and Hiccup Short Circuit Protection
      3. 7.3.3 Under Voltage Lockout (UVLO)
      4. 7.3.4 Thermal Shutdown
    4. 7.4 Device Function Modes
      1. 7.4.1 Enable and Disable (EN)
      2. 7.4.2 Power Save Mode and Forced PWM Mode (MODE)
      3. 7.4.3 Soft Startup (SS/TR)
      4. 7.4.4 Voltage Tracking (SS/TR)
      5. 7.4.5 Power Good (PG)
  8. 8 Application Information
    1. 8.1 Application Information
    2. 8.2 1.8-V Output Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Setting the Output Voltage
        2. 8.2.2.2 Output Filter Design
        3. 8.2.2.3 Inductor Selection
        4. 8.2.2.4 Capacitor Selection
      3. 8.2.3 Application Performance Curves
  9. 9 Power Supply Recommendations
  10. 10PCB Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Information
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.4 Voltage Tracking (SS/TR)

The SS/TR pin is externally driven by another voltage source to achieve output voltage tracking. The application circuit is shown in Figure 4. From 0 V to 0.8 V, the internal reference voltage to the internal error amplifier follows the SS/TR pin voltage. When the SS/TR pin voltage is above 0.8 V, the voltage tracking is disabled and the FB pin voltage is regulated at 0.8 V. The device achieves ratiometric or coincidental (simultaneous) output tracking, as shown in Figure 5.

TPS62097-Q1 Voltagetracking_97.gifFigure 4. Output Voltage Tracking
TPS62097-Q1 Voltagetracking1.gifFigure 5. Voltage Tracking Options

The R2 value should be set properly to achieve accurate voltage tracking by taking 7.5 µA soft startup current into account. 1 kΩ or smaller is a sufficient value for R2.

For decreasing SS/TR pin voltage, the device doesn't sink current from the output when the device is in PSM. So the resulting decreases of the output voltage may be slower than the SS/TR pin voltage if the load is light. When driving the SS/TR pin with an external voltage, do not exceed the voltage rating of the SS/TR pin which is VIN+0.3V.