SLVSGC5B January   2023  – May 2024 TPS62870 , TPS62871 , TPS62872 , TPS62873

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Device Options
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings_Catalog
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Interface Timing Characteristics
    7. 7.7 Timing Requirements
    8. 7.8 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  Fixed-Frequency DCS Control Topology
      2. 8.3.2  Forced PWM and Power Save Modes
      3. 8.3.3  Precise Enable
      4. 8.3.4  Start-Up
      5. 8.3.5  Switching Frequency Selection
      6. 8.3.6  Output Voltage Setting
        1. 8.3.6.1 Output Voltage Range
        2. 8.3.6.2 Output Voltage Setpoint
        3. 8.3.6.3 Non-Default Output Voltage Setpoint
        4. 8.3.6.4 Dynamic Voltage Scaling
      7. 8.3.7  Compensation (COMP)
      8. 8.3.8  Mode Selection and Clock Synchronization (MODE/SYNC)
      9. 8.3.9  Spread Spectrum Clocking (SSC)
      10. 8.3.10 Output Discharge
      11. 8.3.11 Undervoltage Lockout (UVLO)
      12. 8.3.12 Overvoltage Lockout (OVLO)
      13. 8.3.13 Overcurrent Protection
        1. 8.3.13.1 Cycle-by-Cycle Current Limiting
        2. 8.3.13.2 Hiccup Mode
        3. 8.3.13.3 Current Limit Mode
      14. 8.3.14 Power Good (PG)
        1. 8.3.14.1 Standalone or Primary Device Behavior
        2. 8.3.14.2 Secondary Device Behavior
      15. 8.3.15 Remote Sense
      16. 8.3.16 Thermal Warning and Shutdown
      17. 8.3.17 Stacked Operation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-On Reset
      2. 8.4.2 Undervoltage Lockout
      3. 8.4.3 Standby
      4. 8.4.4 On
    5. 8.5 Programming
      1. 8.5.1 Serial Interface Description
      2. 8.5.2 Standard, Fast, Fast Mode Plus Protocol
      3. 8.5.3 I2C Update Sequence
      4. 8.5.4 I2C Register Reset
  10. 9 Register Map
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Selecting the Inductor
        2. 10.2.2.2 Selecting the Input Capacitors
        3. 10.2.2.3 Selecting the Compensation Resistor
        4. 10.2.2.4 Selecting the Output Capacitors
        5. 10.2.2.5 Selecting the Compensation Capacitor, CC
        6. 10.2.2.6 Selecting the Compensation Capacitor, CC2
      3. 10.2.3 Application Curves
    3. 10.3 Best Design Practices
    4. 10.4 Power Supply Recommendations
    5. 10.5 Layout
      1. 10.5.1 Layout Guidelines
      2. 10.5.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

10.2.2.1 Selecting the Inductor

The TPS6287x devices have been optimized for inductors in the range 50nH to 300nH. If the transient response of the converter is limited by the slew rate of the current in the inductor, using a smaller inductor can improve performance. However, the output ripple current increases as the value of the inductor decreases, and higher output current ripple generates higher output voltage ripple, which adds to the transient overshoot or undershoot. The optimal configuration for a given application is always a trade-off between a number of parameters. TI recommends a starting value of 110nH for typical applications.

The peak-to-peak inductor current ripple is given by:

Equation 5. IL(PP)=VOUTVINVIN – VOUTNɸ×L×fsw
Equation 6. IL(PP)=0.753.33.3 –0.751×110×10–9×2.25×106=2.342A

Table 10-4 lists a number of inductors suitable for use with this application. This list is not exhaustive and other inductors from other manufacturers can also be suitable.

Table 10-2 List of Recommended Inductors
Inductance Current RatingDimensionsDC ResistancePart Number(1)
(ISAT at 25°C)(L × W × H)
92nH24A4 × 4 × 1.2mm5.2mΩ (typical)Coilcraft, XEL4012-920NE
100nH30A4 × 4 × 3.2 mm1.5mΩ (typical)Coilcraft, XEL4030-101ME
110nH29A4 × 4 × 2.1 mm1.4mΩ (typical)Coilcraft, XGL4020-111ME
110nH29A3.2 × 2.5 × 2.5 mm1.9mΩ (typical)TDK, CLT32-R11
55nH39.5A3.2 × 2.5 × 2.5 mm1.0mΩ (typical)TDK, CLT32-55N
110nH17.0A3.2 × 2.5 × 2.5mm3.0mΩ (typical)Cyntec, VCTA32252E-R11MS6
100 nH25A4.2 × 4.0 × 2.1mm1.9mΩ (typical)Cyntec, VCHA042A-R10MS62M
100 nH44A5.45 × 5.25 × 2.8mm0.8mΩ (typical)Cyntec, VCHW053T-R10NMS5
(1) See the Third-Party Products Disclaimer.