SLVS833E March   2010  – October 2020 TPS62065 , TPS62067

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 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 Mode Selection (TPS62065)
      2. 8.3.2 Power Good Output (TPS62067)
      3. 8.3.3 Enable
      4. 8.3.4 Clock Dithering
      5. 8.3.5 Undervoltage Lockout
      6. 8.3.6 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Soft Start
      2. 8.4.2 Power Save Mode
      3. 8.4.3 Dynamic Voltage Positioning
      4. 8.4.4 100% Duty Cycle Low Dropout Operation
      5. 8.4.5 Internal Current Limit and Fold-Back Current Limit for Short Circuit Protection
      6. 8.4.6 Output Capacitor Discharge
  9. 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 Voltage Setting
        2. 9.2.2.2 Output Filter Design (Inductor and Output Capacitor)
          1. 9.2.2.2.1 Inductor Selection
          2. 9.2.2.2.2 Output Capacitor Selection
          3. 9.2.2.2.3 Input Capacitor Selection
        3. 9.2.2.3 Checking Loop Stability
      3. 9.2.3 Application Curves
    3. 9.3 System Example
      1. 9.3.1 TPS62067 Adjustable 1.8-V Output
  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 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

The inductor value has a direct effect on the ripple current. The selected inductor must be rated for its DC resistance and saturation current. The inductor ripple current (ΔIL) decreases with higher inductance and increases with higher VIN or VOUT.

Equation 6 calculates the maximum inductor current in PWM mode under static load conditions. The saturation current of the inductor should be rated higher than the maximum inductor current as calculated with Equation 7. This is recommended because during heavy load transient the inductor current rises above the calculated value.

Equation 6. GUID-252537DF-5A1E-40EB-9C0A-59177F3A33FA-low.gif
Equation 7. GUID-6E3BE958-8954-4620-B049-57C44FB86E3D-low.gif

where

  • f = Switching frequency (3 MHz typical)
  • L = Inductor value
  • ΔIL = Peak-to-peak inductor ripple current
  • ILmax = Maximum inductor current

A more conservative approach is to select the inductor current rating just for the switch current limit ILIMF of the converter.

The total losses of the coil have a strong impact on the efficiency of the DC/DC conversion and consist of both the losses in the DC resistance R(DC) and the following frequency-dependent components:

  • The losses in the core material (magnetic hysteresis loss, especially at high switching frequencies)
  • Additional losses in the conductor from the skin effect (current displacement at high frequencies)
  • Magnetic field losses of the neighboring windings (proximity effect)
  • Radiation losses
Table 9-1 List of Inductors
DIMENSIONS (mm3)INDUCTANCE (μH)INDUCTOR TYPESUPPLIER
3.2 × 2.5 × 1 maximum1LQM32PN (MLCC)Murata
3.7 × 4 × 1.8 maximum1LQH44 (wire wound)Murata
4 × 4 × 2.6 maximum1.2NRG4026T (wire wound)Taiyo Yuden
3.5 × 3.7 × 1.8 maximum1.2DE3518 (wire wound)TOKO