SBVS065L December   2005  – December 2024 TPS74301

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configurations and Functions
    1.     Pin Descriptions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Enable/Shutdown
      2. 6.3.2 Power-Good (QFN Package Only)
      3. 6.3.3 Internal Current Limit
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 Disabled
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Input, Output, and Bias Capacitor Requirements
      2. 7.1.2 Transient Response
      3. 7.1.3 Dropout Voltage
      4. 7.1.4 Programmable Sequencing With Track
      5. 7.1.5 Sequencing Requirements
    2. 7.2 Typical Application
      1. 7.2.1 Adjustable Voltage Part and Setting
        1.       34
      2. 7.2.2 Design Requirements
      3. 7.2.3 Detailed Design Procedure
      4. 7.2.4 Application Performance Plots
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Layout Recommendations and Power Dissipation
      2. 7.4.2 Layout Example
      3. 7.4.3 Thermal Protection
      4. 7.4.4 Estimating Junction Temperature
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
      2. 8.1.2 Device Nomenclature
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.1.3 Dropout Voltage

The TPS743 offers industry-leading dropout performance, making the device well-suited for high-current low VIN/low VOUT applications. The extremely low dropout of the TPS743 allows the device to be used instead of a DC/DC converter and still achieve good efficiencies. This efficiency allows users to rethink the power architecture for user applications to find the smallest, simplest, and lowest cost solution.

There are two different specifications for dropout voltage with the TPS743. The first specification (as shown in Figure 7-1) is referred to as VIN Dropout and is for users wishing to apply an external bias voltage to achieve low dropout. This specification assumes that VBIAS is at least 1.62V above VOUT, which is the case for VBIAS when powered by a 3.3V rail with 5% tolerance and with VOUT = 1.5V. If VBIAS is higher than 3.3V × 0.95 or VOUT is less than  1.5V, VIN dropout is less than specified.

TPS74301 Typical Application of the TPS743 Using an Auxiliary Bias RailFigure 7-1 Typical Application of the TPS743 Using an Auxiliary Bias Rail

The second specification (shown in Figure 7-2), referred to as VBIAS Dropout, is for users who wish to tie IN and BIAS together. This option allows the device to be used in applications where an auxiliary bias voltage is unavailable or low dropout is not required. Dropout is limited by BIAS in these applications because VBIAS provides the gate drive to the pass FET, and therefore must be 1.4V above VOUT. Because of this usage, IN and BIAS tied together easily consume huge power. Pay attention not to exceed the power rating of the IC package.

TPS74301 Typical Application of the TPS743xx Without an Auxiliary BiasFigure 7-2 Typical Application of the TPS743xx Without an Auxiliary Bias