SBVS252B October   2014  – February 2019 TPS735-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Internal Current-Limit
      2. 7.3.2 Shutdown
      3. 7.3.3 Dropout Voltage
      4. 7.3.4 Startup and Noise Reduction Capacitor
      5. 7.3.5 Transient Response
      6. 7.3.6 Undervoltage Lockout (UVLO)
      7. 7.3.7 Minimum Load
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation
      2. 7.4.2 Dropout Operation
      3. 7.4.3 Disabled
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Input and Output Capacitor Requirements
        2. 8.2.1.2 Feedback Capacitor Requirements (TPS73501-Q1 only)
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Output Noise
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Board Layout Recommendations to Improve PSRR and Noise Performance
      2. 10.1.2 Thermal Protection
      3. 10.1.3 Package Mounting
      4. 10.1.4 Power Dissipation
      5. 10.1.5 Estimating Junction Temperature
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Device Nomenclature
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.1 Output Noise

In most LDO regulators, the band gap is the dominant noise source. If a noise-reduction capacitor (CNR) is used with the TPS735-Q1 family of devices, the band gap does not contribute significantly to noise. Instead, noise is dominated by the output-resistor divider and the error-amplifier input. To minimize noise in a given application, use a 0.01-μF noise reduction capacitor. For the adjustable version, smaller value resistors in the output resistor divider reduce noise. A parallel combination that gives 2 μA of divider current has the same noise performance as a fixed voltage version with a CNR. To further optimize noise, ESR of the output capacitor can be set to approximately 0.2 Ω. This configuration maximizes phase margin in the control loop, reducing the total output noise up to 10%. The maximum recommended capacitor is 0.01 µF.

Equation 1 calculates the approximate integrated output noise from 10 Hz to 100 kHz with a CNR value of 0.01 µF.

Equation 1. Vn (µVRMS) = 11 (µVRMS / V) × VOUT (V)

The TPS73501-Q1 adjustable version does not have the noise-reduction pin available, so ultra-low noise operation is not possible. Noise can be minimized according to the previously listed recommendations.