SBVS425B December   2022  – June 2025 TPS748A-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  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: IOUT = 50mA
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Enable and Shutdown
      2. 6.3.2 Active Discharge
      3. 6.3.3 Power-Good Output (PG)
      4. 6.3.4 Internal Current Limit
      5. 6.3.5 Thermal Shutdown Protection (TSD)
    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 Dropout Voltage
      3. 7.1.3 Output Noise
      4. 7.1.4 Estimating Junction Temperature
      5. 7.1.5 Soft Start, Sequencing, and Inrush Current
      6. 7.1.6 Power-Good Operation
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 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

6.1 Overview

The TPS748A-Q1 is a low-input, low-output (LILO), low-quiescent-current linear regulator optimized to support excellent transient performance. This regulator uses a low-current bias rail to power all internal control circuitry, allowing the n-type field effect transistor (NMOS) pass transistor to regulate very-low input and output voltages.

Using an NMOS pass transistor offers several critical advantages for many applications. Unlike a p-channel metal-oxide-semiconductor field effect transistor (PMOS) topology device, the output capacitor has little effect on loop stability. This architecture allows the TPS748A-Q1 to be stable with any ceramic capacitor 10μF or greater. Transient response is also superior to PMOS topologies, particularly for low VIN applications.

The TPS748A-Q1 features a programmable, voltage-controlled, soft-start circuit that provides a smooth, monotonic start-up and limits start-up inrush currents caused by large capacitive loads. An enable (EN) pin with hysteresis and deglitch allows slow-ramping signals to be used for sequencing the device. The low VIN and VOUT capability allows for inexpensive, easy-to-design, and efficient linear regulation between the multiple supply voltages often required by processor-intensive systems.