SLVSCN0C june   2014  – may 2023 TPS65263

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 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 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Adjusting the Output Voltage
      2. 8.3.2  Enable and Adjusting UVLO
      3. 8.3.3  Soft-Start Time
      4. 8.3.4  Power-Up Sequencing
      5. 8.3.5  V7V Low Dropout Regulator and Bootstrap
      6. 8.3.6  Out-of-Phase Operation
      7. 8.3.7  Output Overvoltage Protection (OVP)
      8. 8.3.8  Pulse Skipping Mode (PSM)
      9. 8.3.9  Slope Compensation
      10. 8.3.10 Overcurrent Protection
        1. 8.3.10.1 High-Side MOSFET Overcurrent Protection
        2. 8.3.10.2 Low-Side MOSFET Overcurrent Protection
      11. 8.3.11 Power Good
      12. 8.3.12 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Serial Interface Description
      2. 8.4.2 I2C Update Sequence
    5. 8.5 Register Maps
      1. 8.5.1 Register Description
      2. 8.5.2 VOUT1_SEL: Vout1 Voltage Selection Register (offset = 0x00H)
      3. 8.5.3 VOUT2_SEL: Vout2 Voltage Selection Register (offset = 0x01H)
      4. 8.5.4 VOUT3_SEL: Vout3 Voltage Selection Register (offset = 0x02H)
      5. 8.5.5 VOUT1_COM: Buck1 Command Register (offset = 0x03H)
      6. 8.5.6 VOUT2_COM: Buck2 Command Register (offset = 0x04H)
      7. 8.5.7 VOUT3_COM: Buck3 Command Register (offset = 0x05H)
      8. 8.5.8 SYS_STATUS: System Status Register (offset = 0x06H)
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Output Inductor Selection
        2. 9.2.2.2 Output Capacitor Selection
        3. 9.2.2.3 Input Capacitor Selection
        4. 9.2.2.4 Loop Compensation
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

8.3.8 Pulse Skipping Mode (PSM)

The TPS65263 can enter high-efficiency PSM operation at light load current. To disable PSM operation, set VOUTx_COM registers’ bit 1 to 1 through I2C interface.

When a controller is enabled for PSM operation, the peak inductor current is sensed and compared with 230-mA current typically. Because the integrated current comparator catches the peak inductor current only, the average load current entering PSM varies with the applications and external output filters. In PSM, the sensed peak inductor current is clamped at 230 mA, shown in Figure 8-10.

When a controller operates in PSM, the inductor current is not allowed to reverse. The reverse current comparator turns off the low-side MOSFET when the inductor current reaches zero, preventing it from reversing and going negative.

Due to the delay in the circuit and current comparator tdly (typical 50 nS at Vin = 12 V), the real peak inductor current threshold to turn off high-side power MOSFET can shift higher depending on inductor inductance and input/output voltages. The threshold of peak inductor current to turn off high-side power MOSFET can be calculated by Equation 6.

Equation 6. GUID-83364144-C1F5-48EB-9AAD-FB024E438C30-low.gif

When the charge accumulated on Vout capacitor is more than loading need, COMP pin voltage drops to low voltage driven by error amplifier. There is an internal comparator at COMP pin. If comp voltage is lower than 0.35 V, power stage stops switching to save power.

GUID-18244791-E51A-4E69-916B-85FC2E8EE597-low.gifFigure 8-10 PSM Current Comparator