SNVSC83B September   2022  – February 2023 TPSM365R3 , TPSM365R6

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Description (continued)
  6. Device Comparison Table
  7. Pin Configuration and Functions
  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  System Characteristics
    7. 8.7  Typical Characteristics
    8. 8.8  Typical Characteristics: VIN = 12 V
    9. 8.9  Typical Characteristics: VIN = 24 V
    10. 8.10 Typical Characteristics: VIN = 48 V
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Input Voltage Range
      2. 9.3.2  Output Voltage Selection
      3. 9.3.3  Input Capacitors
      4. 9.3.4  Output Capacitors
      5. 9.3.5  Enable, Start-Up, and Shutdown
      6. 9.3.6  External CLK SYNC (with MODE/SYNC)
        1. 9.3.6.1 Pulse-Dependent MODE/SYNC Pin Control
      7. 9.3.7  Switching Frequency (RT)
      8. 9.3.8  Power-Good Output Operation
      9. 9.3.9  Internal LDO, VCC UVLO, and BIAS Input
      10. 9.3.10 Bootstrap Voltage and VBOOT-UVLO (BOOT Terminal)
      11. 9.3.11 Spread Spectrum
      12. 9.3.12 Soft Start and Recovery from Dropout
        1. 9.3.12.1 Recovery from Dropout
      13. 9.3.13 Overcurrent Protection (OCP)
      14. 9.3.14 Thermal Shutdown
    4. 9.4 Device Functional Modes
      1. 9.4.1 Shutdown Mode
      2. 9.4.2 Standby Mode
      3. 9.4.3 Active Mode
        1. 9.4.3.1 CCM Mode
        2. 9.4.3.2 AUTO Mode - Light Load Operation
          1. 9.4.3.2.1 Diode Emulation
          2. 9.4.3.2.2 Frequency Reduction
        3. 9.4.3.3 FPWM Mode - Light Load Operation
        4. 9.4.3.4 Minimum On-time (High Input Voltage) Operation
      4. 9.4.4 Dropout
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 600-mA and 300-mA Synchronous Buck Regulator for Industrial Applications
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1  Custom Design With WEBENCH® Tools
          2. 10.2.1.2.2  Output Voltage Setpoint
          3. 10.2.1.2.3  Switching Frequency Selection
          4. 10.2.1.2.4  Input Capacitor Selection
          5. 10.2.1.2.5  Output Capacitor Selection
          6. 10.2.1.2.6  VCC
          7. 10.2.1.2.7  CFF Selection
          8. 10.2.1.2.8  Power-Good Signal
          9. 10.2.1.2.9  Maximum Ambient Temperature
          10. 10.2.1.2.10 Other Connections
        3. 10.2.1.3 Application Curves
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
        1. 10.4.1.1 Ground and Thermal Considerations
      2. 10.4.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Device Nomenclature
      3. 11.1.3 Development Support
        1. 11.1.3.1 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

Diode emulation prevents reverse current through the inductor which requires a lower frequency needed to regulate given a fixed peak inductor current. Diode emulation also limits ripple current as frequency is reduced. With a fixed peak current, as output current is reduced to zero, frequency must be reduced to near zero to maintain regulation.

In auto mode, the low-side device is turned off after SW node current is near zero. As a result, after output current is less than half of what inductor ripple can be in CCM, the part operates in DCM which is equivalent to the statement that diode emulation is active.
Figure 9-13 PFM Operation

The TPSM365Rx has a minimum peak inductor current setting (see IPEAK-MIN in GUID-XXXXXXXX-SF0T-XXXX-XXXX-000000280921.html#GUID-XXXXXXXX-SF0T-XXXX-XXXX-000000280921) while in auto mode. After current is reduced to a low value with fixed input voltage, on-time is constant. Regulation is then achieved by adjusting frequency. This mode of operation is called PFM mode regulation.