ZHCSOW9C october   2022  – july 2023 TPSM82912 , TPSM82913 , TPSM82913E

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Smart Config (S-CONF)
      2. 7.3.2  Device Enable (EN/SYNC)
      3. 7.3.3  Device Synchronization (EN/SYNC)
      4. 7.3.4  Spread Spectrum Modulation
      5. 7.3.5  Output Discharge
      6. 7.3.6  Undervoltage Lockout (UVLO)
      7. 7.3.7  Power-Good Output
      8. 7.3.8  Noise Reduction and Soft-Start Capacitor (NR/SS)
      9. 7.3.9  Current Limit and Short-Circuit Protection
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fixed Frequency Pulse Width Modulation
      2. 7.4.2 Low Duty Cycle Operation
      3. 7.4.3 High Duty Cycle Operation (100% Duty Cycle)
      4. 7.4.4 Second Stage L-C Filter Compensation (Optional)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 External Component Selection
          1. 8.2.2.2.1 Switching Frequency Selection
          2. 8.2.2.2.2 Output Capacitor Selection
          3. 8.2.2.2.3 Ferrite Bead Selection for Second L-C Filter
          4. 8.2.2.2.4 Input Capacitor Selection
          5. 8.2.2.2.5 Setting the Output Voltage
          6. 8.2.2.2.6 NR/SS Capacitor Selection
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 第三方产品免责声明
      2. 9.1.2 Development Support
        1. 9.1.2.1 Custom Design With WEBENCH® Tools
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 接收文档更新通知
    4. 9.4 支持资源
    5. 9.5 Trademarks
    6. 9.6 静电放电警告
    7. 9.7 术语表
  11. 10Mechanical, Packaging, and Orderable Information

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

7.3.8 Noise Reduction and Soft-Start Capacitor (NR/SS)

A capacitor connected to this pin reduces the low frequency noise of the converter and sets the soft-start time. The larger the capacitor, the lower the noise and the longer the start-up time of the converter. The module has an internal 220-nF capacitor connected to the NR/SS pin. If no external capacitor is connected to the NR/SS pin, the default start-up time is 2.35 ms, although longer start-up times and additional noise reduction can be achieved with additional capacitance connected to the NR/SS pin. The maximum NR/SS cap is 3.3 µF for a start-up time of 35 ms.During soft start with a light load, the device skips switching pulses as needed to not discharge the output voltage. The device can start into a pre-biased output voltage.

The device achieves low noise by adding an R-C filter to the reference voltage, as shown in Functional Block Diagram. During start-up, the NR/SS capacitor is charged with a constant current of 75 µA (typical) to 0.8 V. Larger NR/SS capacitors provide for lower low frequency noise, as shown in Figure 6-29.