SLVSHK8 December   2023 TPSM64406

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 System Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Input Voltage Range (VIN1, VIN2)
      2. 7.3.2  Enable EN Pin and Use as VIN UVLO
      3. 7.3.3  CONFIG Device Configuration Pin
      4. 7.3.4  Adjustable Switching Frequency
      5. 7.3.5  Spread Spectrum
      6. 7.3.6  Adjustable Output Voltage (FB)
      7. 7.3.7  Input Capacitors
      8. 7.3.8  Output Capacitors
      9. 7.3.9  SYNC Allows Clock Synchronization and Mode Selection
      10. 7.3.10 Power-Good Output Voltage Monitoring
      11. 7.3.11 Bias Supply Regulator (VCC, VOSNS)
      12. 7.3.12 Overcurrent Protection (OCP)
      13. 7.3.13 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode
  9. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design 1 – High-efficiency Dual Output 5 V at 3 A, 3.3 V at 3 A, Synchronous Buck Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Output Voltage Setpoint
          2. 8.2.1.2.2 Switching Frequency Selection
          3. 8.2.1.2.3 Input Capacitor Selection
          4. 8.2.1.2.4 Output Capacitor Selection
          5. 8.2.1.2.5 Other Considerations
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Design 2 – High-efficiency 6 A Synchronous Buck Regulator for Industrial Applications
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Output Voltage Setpoint
          2. 8.2.2.2.2 Switching Frequency Selection
          3. 8.2.2.2.3 Input Capacitor Selection
          4. 8.2.2.2.4 Output Capacitor Selection
          5. 8.2.2.2.5 Other Connections
        3. 8.2.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Thermal Design and Layout
      2. 8.4.2 Layout Example
  10. 9 Custom Design With WEBENCH® Tools
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
      2. 10.1.2 Development Support
        1. 10.1.2.1 Custom Design With WEBENCH® Tools
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Mechanical Data

Package Options

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

7.3.4 Adjustable Switching Frequency

The frequency is set using a resistor on the RT pin. A resistor to AGND is used to set the adjustable operating frequency. See below for resistor values. A resistor value that falls outside of the recommended range can cause the device to stop switching. Do not apply a pulsed signal to this pin to force synchronization. If synchronization is needed, see the SYNC pin.

Equation 3. R T k Ω = 16.4 F S W M H z - 0.633

For example, for fSW = 400 kHz, RT = (16.4 / 0.4) - 0.633 = 40.37, so a 40.2-kΩ resistor is selected as the closest choice.

Table 7-3 Typical RT values
RT (kΩ) Frequency (kHz)
6.81 2206
7.15 2106
15.4 1005
31.6 497.4
39.2 402
158 101
GUID-EFE99FB6-F470-43E4-8CF3-B7600700686C-low.svg Figure 7-3 Setting Clock Frequency