SLUSG64 April   2025 TPSM843521

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Fixed Frequency Peak Current Mode
      2. 6.3.2  Mode Selection
      3. 6.3.3  Voltage Reference
      4. 6.3.4  Output Voltage Setting
      5. 6.3.5  Switching Frequency Selection, Synchronization
      6. 6.3.6  Phase Shift
      7. 6.3.7  Enable and Adjusting Undervoltage Lockout
      8. 6.3.8  External Soft Start and Prebiased Soft Start
      9. 6.3.9  Power Good
      10. 6.3.10 Minimum On Time, Minimum Off Time, and Frequency Foldback
      11. 6.3.11 Frequency Spread Spectrum
      12. 6.3.12 Overvoltage Protection
      13. 6.3.13 Overcurrent and Undervoltage Protection
      14. 6.3.14 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Modes Overview
      2. 6.4.2 Heavy Load Operation
      3. 6.4.3 Pulse Frequency Modulation
      4. 6.4.4 Forced Continuous Conduction Modulation
      5. 6.4.5 Dropout Operation
      6. 6.4.6 Minimum On-Time Operation
      7. 6.4.7 Shutdown Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Custom Design With WEBENCH® Tools
        2. 7.2.2.2 Output Voltage Resistors Selection
        3. 7.2.2.3 Choosing Switching Frequency
        4. 7.2.2.4 Soft-Start Capacitor Selection
        5. 7.2.2.5 Output Capacitor Selection
        6. 7.2.2.6 Input Capacitor Selection
        7. 7.2.2.7 Feedforward Capacitor CFF Selection
        8. 7.2.2.8 Maximum Ambient Temperature
      3. 7.2.3 Application Curves
    3. 7.3 Best Design Practices
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
      2. 8.1.2 Development Support
        1. 8.1.2.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

3 Description

The TPSM843521 is a high-efficiency, high-power density, and easy-to-use, synchronous buck power module with high design flexibility. With operating input voltage ranging from 3.8V to 18V, the TPSM843521 is designed for systems powered from 5V, 12V power-bus rails. The device supports up to 5A continuous output current and 98% maximum duty cycle.

TPSM843521 uses fixed frequency peak current control with internal compensation for fast transient response and good line and load regulation. With the optimized internal loop compensation, the device eliminates the need for external compensation over a wide output voltage range and switching frequency.

Package Information
PRT NUMBERPACKAGE(1)PACKAGE SIZE(2)
TPSM843521RCJ (QFN-FCMOD, 9)3.3mm × 4.5mm
(1) For more information, see Section 10.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
TPSM843521 Simplified SchematicSimplified Schematic
TPSM843521 TPSM843521 Efficiency, PFM TPSM843521 Efficiency, PFM

TPSM843521 allows high design flexibility with wide supported switching frequency of 200kHz – 2.2MHz set by the RT/SYNC pin. The device has the option for pulse frequency modulation (PFM), forced continuous conduction modulation (FCCM) at light load condition, and adjustable soft-start (SS) time / power-good (PG) indicator with different configuration of the MODE pin.

TPSM843521 provides protection functions including thermal shutdown, input undervoltage lockout, cycle-by-cycle current limit, and hiccup short-circuit protection. TPSM843521 is available in a 9-pin, 3.3mm × 4.5mm, QFN package, and the pinout is available for single-layer PCB layout. The junction temperature is specified from –40°C to 125°C.