SBVS141D April   2010  – December 2023 TPS74701-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 = 50 mA
    7. 5.7 Typical Characteristics: VEN = VIN = 1.8 V, VOUT = 1.5 V
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Transient Response
      2. 6.3.2 Dropout Voltage
      3. 6.3.3 Output Noise
      4. 6.3.4 Enable and Shutdown
      5. 6.3.5 Power Good
      6. 6.3.6 Internal Current Limit
      7. 6.3.7 Thermal Protection
    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
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Input, Output, and Bias Capacitor Requirements
        2. 7.2.2.2 Programmable Soft-Start
        3. 7.2.2.3 Sequencing Requirements
      3. 7.2.3 Application Curves
    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. 7.4.1.2 Estimating Junction Temperature
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
      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

6.3.3 Output Noise

The TPS74701-Q1 provides low output noise when a soft-start capacitor is used. When the device reaches the end of the soft-start cycle, the soft-start capacitor serves as a filter for the internal reference. By using a 0.001-µF soft-start capacitor, the output noise is reduced by half and is typically 30 µVRMS for a 1.2-V output (10 Hz to 100 kHz) for the legacy chip and 24 µVRMS for a 1.2-V output (10 Hz to 100 kHz) with the new chip. Further increasing CSS has little effect on noise. Because most of the output noise is generated by the internal reference, the noise is a function of the set output voltage. The RMS noise with a 0.001-µF soft-start capacitor is given in the following equations:

Equation 1. V N = 25 ( μ V R M S V ) × V O U T ( V ) (Legacy Chip)
Equation 2. V N = 20 ( μ V R M S V ) × V O U T ( V ) (New Chip)

The low output noise of the TPS74701-Q1 makes the device a good choice for powering transceivers, PLLs, or other noise-sensitive circuitry.