SLVSCF0B October   2015  – June 2017 TPS65321-Q1

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 Buck Regulator
        1. 7.3.1.1  Fixed-Frequency PWM Control
        2. 7.3.1.2  Slope Compensation Output
        3. 7.3.1.3  Pulse-Skip Eco-mode™ Control Scheme
        4. 7.3.1.4  Dropout Mode Operation and Bootstrap Voltage (BOOT)
        5. 7.3.1.5  Error Amplifier
        6. 7.3.1.6  Voltage Reference
        7. 7.3.1.7  Adjusting the Output Voltage
        8. 7.3.1.8  Soft-Start and Tracking Pin (SS/TR)
        9. 7.3.1.9  Reset Output, nRST
        10. 7.3.1.10 Overload-Recovery Circuit
        11. 7.3.1.11 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
        12. 7.3.1.12 Overcurrent Protection and Frequency Shift
        13. 7.3.1.13 Selecting the Switching Frequency
        14. 7.3.1.14 How to Interface to RT/CLK Pin
        15. 7.3.1.15 Overvoltage Transient Protection
        16. 7.3.1.16 Small-Signal Model for Loop Response
        17. 7.3.1.17 Simple Small-Signal Model for Peak-Current Mode Control
        18. 7.3.1.18 Small-Signal Model for Frequency Compensation
      2. 7.3.2 LDO Regulator
        1. 7.3.2.1 Charge-Pump Operation
        2. 7.3.2.2 Low-Voltage Tracking
        3. 7.3.2.3 Adjusting the Output Voltage
      3. 7.3.3 Thermal Shutdown
      4. 7.3.4 Enable and Undervoltage Lockout
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Soft-Start Discharge
      2. 8.1.2 Passive Discharge Through a Resistor in Parallel With the SS Capacitor
      3. 8.1.3 Active Discharge Through A NPN Transistor
    2. 8.2 Typical Applications
      1. 8.2.1 2.2-MHzSwitching Frequency, 9-V to 16-V Input, 3.3-V Output Buck Regulator, 5-V Output LDO Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Switching Frequency Selection for the Buck Regulator
          2. 8.2.1.2.2  Output Inductor Selection for the Buck Regulator
          3. 8.2.1.2.3  Output Capacitor Selection for the Buck Regulator
          4. 8.2.1.2.4  Catch Diode Selection for the Buck Regulator
          5. 8.2.1.2.5  Input Capacitor Selection for the Buck Regulator
          6. 8.2.1.2.6  Soft-Start Capacitor Selection for the Buck Regulator
          7. 8.2.1.2.7  Bootstrap Capacitor Selection for the Buck Regulator
          8. 8.2.1.2.8  Output Voltage and Feedback Resistor Selection for the Buck Regulator
          9. 8.2.1.2.9  Frequency Compensation Selection for the Buck Regulator
          10. 8.2.1.2.10 LDO Regulator
          11. 8.2.1.2.11 Power Dissipation
            1. 8.2.1.2.11.1 Power Dissipation Losses of the Buck Regulator
          12. 8.2.1.2.12 Power Dissipation Losses of the LDO Regulator
          13. 8.2.1.2.13 Total Device Power Dissipation Losses and Junction Temperature
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Design Example With 500-kHz Switching Frequency
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Selecting the Switching Frequency
          2. 8.2.2.2.2 Output Inductor Selection
          3. 8.2.2.2.3 Output Capacitor
          4. 8.2.2.2.4 Compensation
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PWP|14
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9 Power Supply Recommendations

The buck regulator is designed to operate from an input voltage supply range between 3.6 V and 36 V. The linear regulator is designed to operate from an input supply voltage up to 36 V. Both input supplies must be well regulated. If the input supply connected to the VIN pin is located more than a few inches from the TPS65321-Q1 converter additional bulk capacitance may be required in addition to the ceramic bypass capacitors. An electrolytic capacitor with a value of 100 μF is a typical choice.