SLVSC58B June   2016  – March 2019 TPS63070

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Efficiency vs Output Current; Vo = 5 V
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram TPS63070
    3. 8.3 Functional Block Diagram TPS630701
    4. 8.4 Feature Description
      1. 8.4.1  Control Loop Description
      2. 8.4.2  Precise Enable
      3. 8.4.3  Power Good
      4. 8.4.4  Soft Start
      5. 8.4.5  PS/SYNC
      6. 8.4.6  Short Circuit Protection
      7. 8.4.7  VSEL and FB2 pins
      8. 8.4.8  Overvoltage Protection
      9. 8.4.9  Undervoltage Lockout
      10. 8.4.10 Overtemperature Protection
    5. 8.5 Device Functional Modes
      1. 8.5.1 Power Save Mode
      2. 8.5.2 Current Limit
      3. 8.5.3 Output Discharge Function (TPS630702 only)
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application for adjustable version
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Programming The Output Voltage
        2. 9.2.2.2 Inductor Selection
        3. 9.2.2.3 Capacitor Selection
          1. 9.2.2.3.1 Input Capacitor
          2. 9.2.2.3.2 Output Capacitor
      3. 9.2.3 Application Curves
    3. 9.3 Typical Application for Fixed Voltage Version
      1. 9.3.1 Design Requirements
      2. 9.3.2 Detailed Design Procedure
      3. 9.3.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Thermal Information
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.4.5 PS/SYNC

The PS/SYNC pin has two functions:

  • switching between forced PWM mode and power save mode
  • synchronizing to an external clock applied at pin PS/SYNC

When PS/SYNC is set high, the device operates in power save mode at low output current. For an average inductor current above a certain threshold the device switches to forced PWM mode. The automatic switch-over from PFM to PWM and vice versa is done such that the efficiency is kept at the maximum possible level. It is not based on a fixed threshold but at a current that depends on input voltage and output voltage to keep the efficiency at the maximum possible level.

The power save mode is disabled when PS/SYNC is set low. The device then operates in forced fixed frequency PWM mode independent of the output current.

TPS6307x can be synchronized to an external clock applied at pin PS/SYNC. Details about the voltage level and frequency range can be found in the electrical characteristics. When an external clock is detected, TPS6307x switches from internal clock or power save mode to fixed frequency operation based on the external clock frequency. When the external clock is removed, TPS6307x switches back to internal clock or power save mode depending on the average inductor current and status of the PS/SYNC pin. The PS/SYNC pin has two parallel input stages, a slow one with the precise threshold for PWM/PFM mode change and a fast digital input stage for an external clock signal for synchronization.

It is recommended to not connect PS/SYNC directly to VIN but use a resistor in series in the range of 1kΩ to 1MΩ. If several inputs like EN and PS/SYNC are connected to VIN, the resistor can be shared. No resistor is required if the pin is driven from an analog or digital signal rather than a supply voltage.