SGLS303G May   2005  – December 2024 TPS732-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 Thermal Information
    6. 5.6 Electrical Characteristics
    7. 5.7 Switching Characteristics
    8. 5.8 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 Internal Current Limit
      2. 6.3.2 Shutdown
      3. 6.3.3 Dropout Voltage
      4. 6.3.4 Transient Response
      5. 6.3.5 Reverse Current
      6. 6.3.6 Thermal Protection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
  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 and Output Capacitor Requirements
        2. 7.2.2.2 Output Noise
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
      3. 7.4.3 Power Dissipation
      4. 7.4.4 Package Mounting
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Device Nomenclature
      2. 8.1.2 Related Documentation
    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

7.2.2.2 Output Noise

A precision band-gap reference is used to generate the internal reference voltage, VREF. This reference is the dominant noise source within the TPS732-Q1 family of devices and generates approximately 32 μVRMS (10 Hz to 100 kHz) at the reference output (NR). The regulator control loop gains up the reference noise with the same gain as the reference voltage, so that the noise voltage of the regulator is approximately given by:

Equation 3. TPS732-Q1

Because the value of VREF is 1.2 V, this relationship reduces to:

Equation 4. TPS732-Q1

where

  • CNR does not exist

An internal 27-kΩ resistor in series with the noise reduction pin (NR) forms a low-pass filter for the voltage reference when an external noise reduction capacitor, CNR, is connected from NR to ground. For CNR = 10 nF, the total noise in the 10-Hz to 100-kHz bandwidth is reduced by a factor of approximately 3.2, giving the approximate relationship:

Equation 5. TPS732-Q1

where

  • CNR = 10 nF

This noise reduction effect is shown as RMS Noise Voltage vs CNR in Typical Characteristics.

The TPS73201-Q1 adjustable version does not have the noise-reduction pin available. However, connecting a feedback capacitor, CFB, from the output to the FB pin reduces output noise and improve load transient performance.

The TPS732-Q1 family of devices uses an internal charge pump to develop an internal supply voltage sufficient to drive the gate of the NMOS pass element above VOUT. The charge pump generates approximately 250 μV of switching noise at approximately 2 MHz; however, charge-pump noise contribution is negligible at the output of the regulator for most values of IOUT and COUT.