SLVSCB2D October   2013  – April 2018 TPS7B67-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Adjustable Output Option
      2.      Fixed Output Option
  4. 4 Revision History
  5. 5 Device Comparison
  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 Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Enable (EN)
      2. 8.3.2 Regulated Output (VOUT)
      3. 8.3.3 Power-On-Reset (RESET)
      4. 8.3.4 Reset Delay Timer (DELAY)
      5. 8.3.5 Adjustable Output Voltage (ADJ for TPS7B6701)
      6. 8.3.6 Undervoltage Shutdown
      7. 8.3.7 Thermal Shutdown
      8. 8.3.8 Thermal Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation With VIN < 4 V
      2. 8.4.2 Operation With EN Control
  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 Power Dissipation and Thermal Considerations
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Dropout Recovery
      1. 10.1.1 LDO Dropout Recovery Explained
      2. 10.1.2 TPS7B67xx-Q1 Dropout During Startup
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Enhanced Thermal Pad
      2. 11.1.2 Package Mounting
      3. 11.1.3 Board Layout Recommendations to Improve PSRR and Noise Performance
      4. 11.1.4 Additional Layout Considerations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

9.2.2.1 Power Dissipation and Thermal Considerations

Device power dissipation is calculated with Equation 3.

Equation 3. PD = IO × (VI – VO) + IQ × VI

where

  • PD = continuous power dissipation
  • IO = output current
  • VI = input voltage
  • VO = output voltage

As IQ « IO, the term IQ × VI in Equation 3 can be ignored.

For a device under operation at a given ambient air temperature (TA), calculate the junction temperature (TJ) with Equation 4.

Equation 4. TJ = TA + (RθJA × PD)

where

  • RθJA = junction-to-ambient air thermal impedance

A rise in junction temperature because of power dissipation can be calculated with Equation 5.

Equation 5. ΔT = TJ – TA = (RθJA × PD)

For a given maximum junction temperature (TJM), the maximum ambient air temperature (TAM) at which the device can operate is calculated with Equation 6.

Equation 6. TAM = TJM – (RθJA × PD)