SNVSC83B September   2022  – February 2023 TPSM365R3 , TPSM365R6

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  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. 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

9.3.7 Switching Frequency (RT)

The select variants in the TPSM365Rx family with the RT pin allows the power designers to set any desired operating frequency between 200 kHz and 2.2 MHz in their applications. See #X2294 to determine the resistor value needed for the desired switching frequency or simply select from Table 9-6. The RT pin and the
MODE/SYNC pin variants share the same pin location. The power supply designer can either use the RT pin variant and adjust the switching frequency of operation as warranted by the application or use the MODE/SYNC variant and synchronize to an external clock signal. See Table 9-5 for selection on programming the RT pin.

Table 9-5 RT Pin Setting
RT INPUT SWITCHING FREQUENCY
VCC 1 MHz
GND 2.2 MHz
RT to GND Adjustable according to #X2294
Float (not recommended) No switching
Equation 7. GUID-31123149-D9FB-4987-B75B-56F3A7B74D8A-low.gif

where

  • RT is the frequency setting resistor value (kΩ).
  • FSW is the switching frequency (kHz).

Figure 9-9 RT Values vs Frequency

The switching frequency must be selected based on the output voltage setting of the device. See Table 9-6 for RRT resistor values and the allowable output voltage range for a given switching frequency for common input voltages.

Table 9-6 Switching Frequency Versus Output Voltage (IOUT = 600 mA)
FSW (kHz) RRT (kΩ) VIN = 5 V VIN = 12 V VIN = 24 V VIN = 36 V VIN = 48 V
VOUT RANGE (V) VOUT RANGE (V) VOUT RANGE (V) VOUT RANGE (V) VOUT RANGE (V)
MIN MAX MIN MAX MIN MAX MIN MAX MIN MAX
200 81.6 1 1 - - - - - - - -
400 40.2 1 2.4 1 2 1 1.9 1.1 1.8 1.4 1.8
600 26.7 1 2.7 1 4 1.1 3 1.6 2.8 2.1 2.8
800 19.8 1 3.1 1 6 1.4 4.4 2.1 3.9 2.7 3.8
1000 15.8 1 3.5 1 6 1.7 5.8 2.6 5.1 3.4 4.9
1200 13.2 1 3.9 1.1 6 2.1 8 3.1 6.4 4.1 6
1400 11.3 1 4 1.2 6.4 2.4 12 3.6 7.9 4.8 7.3
1600 9.76 1 4 1.4 7 2.7 12 4.1 9.7 5.4 8.6
1800 8.66 1 4 1.6 7.4 3.1 12 4.6 11.9 6.1 10.1
2000 7.77 1 4 1.7 7.8 3.4 12 5.1 13 6.8 11.7
2200 7.06 1 4 1.9 8.2 3.7 12 5.6 13 7.4 13