SLVSFQ9A August   2021  – November 2021 TPSM8A28 , TPSM8A29

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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 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  Internal VCC LDO and Using External Bias on VCC Pin
      2. 7.3.2  Enable
      3. 7.3.3  Output Voltage Setting
        1. 7.3.3.1 Remote Sense
      4. 7.3.4  Internal Fixed Soft Start and External Adjustable Soft Start
      5. 7.3.5  External REFIN for Output Voltage Tracking
      6. 7.3.6  Frequency and Operation Mode Selection
      7. 7.3.7  D-CAP3™ Control
      8. 7.3.8  Low-Side FET Zero-Crossing
      9. 7.3.9  Current Sense and Positive Overcurrent Protection
      10. 7.3.10 Low-Side FET Negative Current Limit
      11. 7.3.11 Power Good
      12. 7.3.12 Overvoltage and Undervoltage Protection
      13. 7.3.13 Out-Of-Bounds (OOB) Operation
      14. 7.3.14 Output Voltage Discharge
      15. 7.3.15 UVLO Protection
      16. 7.3.16 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Auto-Skip Eco-Mode Light Load Operation
      2. 7.4.2 Forced Continuous-Conduction Mode
      3. 7.4.3 Powering the Device From a 12-V Bus
      4. 7.4.4 Powering the Device From a 5.0-V Bus
      5. 7.4.5 Powering the Device From a Split-Rail Configuration
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Output Voltage Setting Point
        2. 8.2.2.2  Choose the Inductor
        3. 8.2.2.3  Set the Current Limit (TRIP)
        4. 8.2.2.4  Choose the Output Capacitor
        5. 8.2.2.5  Choose the Input Capacitors (CIN)
        6. 8.2.2.6  Soft-Start Capacitor (SS/REFIN Pin)
        7. 8.2.2.7  EN Pin Resistor Divider
        8. 8.2.2.8  VCC Bypass Capacitor
        9. 8.2.2.9  BOOT Capacitor
        10. 8.2.2.10 PGOOD Pullup Resistor
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
      1. 10.2.1 Thermal Performance on the TI EVM
    3. 10.3 EMI
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    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

7.3.6 Frequency and Operation Mode Selection

The TPSM8A29 provides forced CCM operation for tight output ripple applications and auto-skip Eco-mode for high light-load efficiency. The TPSM8A29 allows users to select the switching frequency and operation mode by connecting a resistor from the MODE pin to the AGND pin. Table 7-1 lists the resistor values for the switching frequency and operation mode selection. TI recommends ±1% tolerance resistors with a typical temperature coefficient of ±100 ppm/°C.

The MODE state is set and latched during the internal power-on delay period. Changing the MODE pin resistance after the power-on delay does not change the status of the device. The internal circuit sets the MODE pin status to 600 kHz / Skip mode if the MODE pin is left open during the power-on delay period.

To make sure the internal circuit detects the desired option correctly, do not place any capacitor on the MODE pin.

Table 7-1 MODE Pin Selection
MODE PIN CONNECTIONSOPERATION MODE UNDER LIGHT LOADSWITCHING FREQUENCY
(fSW) (kHz)
Short to VCCSkip-mode600
243-kΩ ± 10% to AGNDSkip-mode800
121-kΩ ± 10% to AGNDSkip-mode1000
60.4-kΩ ±10% to AGNDForced CCM1000
30.1-kΩ ±10% to AGNDForced CCM800
Short to AGNDForced CCM600