SBVS414 November   2021 TPS7H1210-SEP

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Enable Pin Operation
      3. 7.3.3 Programmable Soft-Start
      4. 7.3.4 Thermal Protection
    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
      1. 8.1.1 Adjustable Operation
      2. 8.1.2 Capacitor Recommendations
      3. 8.1.3 Noise Reduction and Feed-Forward Capacitor Requirements
      4. 8.1.4 Power-Supply Rejection Ratio (PSRR)
      5. 8.1.5 Output Noise
      6. 8.1.6 Transient Response
      7. 8.1.7 Post DC-DC Converter Filtering
      8. 8.1.8 Power for Precision Analog
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Do's and Don’ts
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Improve PSRR and Noise Performance
    2. 10.2 Layout Example
    3. 10.3 Thermal Performance
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Spice Models
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

8.1.3 Noise Reduction and Feed-Forward Capacitor Requirements

Although the noise-reduction (CNR_SS) capacitor is not needed to achieve stability, TI highly recommends using a 100-nF noise-reduction capacitor to minimize noise and maximize AC performance. The noise-reduction capacitor is especially important at low currents as shown in Figure 6-22.

It is generally recommended to not use a feed-forward capacitor. While a feed-forward capacitor can provide some improvements in PSRR at certain frequencies, it also has additional risks. See Pros and Cons of Using a Feed-Forward Capacitor with a Low Dropout Regulator for additional information.

CAUTION: Using a feed-forward capacitor with the TPS7H1210-SEP can cause the FB pin to go too positive during shutdown, thus damaging the device.

Figure 8-1 shows the different PSRR performance of the device with and without a feed-forward capacitor with VIN = –13 V, VOUT = –12 V, IOUT = 1 A, CNR_SS = 100 nF, and COUT = 50 μF.

Figure 8-1 Power-Supply Rejection Ratio vs Frequency Across CFF