SLVS927F March   2009  – July 2018 TPS65023-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Step-Down Converters, VDCDC1, VDCDC2, and VDCDC3
      2. 8.3.2 Soft Start
      3. 8.3.3 Active Discharge When Disabled
      4. 8.3.4 Power-Good Monitoring
      5. 8.3.5 Low-Dropout Voltage Regulators
      6. 8.3.6 Undervoltage Lockout
    4. 8.4 Device Functional Modes
      1. 8.4.1 VRTC Output and Operation With or Without Backup Battery
      2. 8.4.2 Power-Save Mode Operation (PSM)
      3. 8.4.3 Low-Ripple Mode
      4. 8.4.4 100% Duty-Cycle Low-Dropout Operation
      5. 8.4.5 System Reset and Control Signals
        1. 8.4.5.1 DEFLDO1 and DEFLDO2
        2. 8.4.5.2 Interrupt Management and the INT Pin
    5. 8.5 Programming
      1. 8.5.1 Power-Up Sequencing
      2. 8.5.2 Serial Interface
    6. 8.6 Register Maps
      1. 8.6.1 VERSION Register (address: 00h) Read-Only
      2. 8.6.2 PGOODZ Register (address: 01h) Read-Only
        1. Table 5. PGOODZ Register Field Descriptions
      3. 8.6.3 MASK Register (address: 02h)
      4. 8.6.4 REG_CTRL Register (address: 03h)
        1. Table 6. REG_CTRL Register Field Descriptions
      5. 8.6.5 CON_CTRL Register (address: 04h)
        1. Table 7. CON_CTRL Register Field Descriptions
      6. 8.6.6 CON_CTRL2 Register (address: 05h)
        1. Table 8. CON_CTRL2 Register Field Descriptions
      7. 8.6.7 DEFCORE Register (address: 06h)
        1. Table 9. DEFCORE Register Field Descriptions
      8. 8.6.8 DEFSLEW Register (address: 07h)
        1. Table 10. DEFSLEW Register Field Descriptions
      9. 8.6.9 LDO_CTRL Register (address: 08h)
        1. Table 11. LDO_CTRL Register Field Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Reset Condition of DCDC1
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inductor Selection for the DC-DC Converters
        2. 9.2.2.2 Output Capacitor Selection
        3. 9.2.2.3 Input Capacitor Selection
        4. 9.2.2.4 Output Voltage Selection
        5. 9.2.2.5 VRTC Output
        6. 9.2.2.6 LDO1 and LDO2
        7. 9.2.2.7 TRESPWRON
        8. 9.2.2.8 VCC Filter
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.4.4 100% Duty-Cycle Low-Dropout Operation

The TPS65023-Q1 converters offer a low input-to-output voltage difference while still maintaining operation with the use of the 100% duty-cycle mode. In this mode, the P-channel switch is constantly turned on. This is particularly useful in battery-powered applications to achieve longest operation time by taking full advantage of the whole battery voltage range. The minimum input voltage required to maintain DC regulation depends on the load current and output voltage. Use Equation 3 to calculate the minimum input voltage.

Equation 3. TPS65023-Q1 q3_vinmin_lvs927.gif

where

  • IOUT(max) = maximum load current (Note: ripple current in the inductor is zero under these conditions)
  • rDS(on)max = maximum P-channel switch rDS(on)
  • RL = DC resistance of the inductor
  • VOUT(min) = nominal output voltage minus 2% tolerance limit