JAJSMO5C August   2000  – August 2021 DCV010505 , DCV010505D , DCV010512 , DCV010512D , DCV010515 , DCV010515D , DCV011512D , DCV011515D , DCV012405 , DCV012415D

PRODUCTION DATA  

  1. 特長
  2. アプリケーション
  3. 概要
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1  Isolation
        1. 8.3.1.1 Operation or Functional Isolation
        2. 8.3.1.2 Basic or Enhanced Isolation
        3. 8.3.1.3 Working Voltage
        4. 8.3.1.4 Isolation Voltage Rating
        5. 8.3.1.5 Repeated High-Voltage Isolation Testing
      2. 8.3.2  Power Stage
      3. 8.3.3  Oscillator and Watchdog Circuit
      4. 8.3.4  Thermal Shutdown
      5. 8.3.5  Synchronization
      6. 8.3.6  Light Load Operation (< 10%)
      7. 8.3.7  Load Regulation (10% to 100%)
      8. 8.3.8  Construction
      9. 8.3.9  Thermal Management
      10. 8.3.10 Power-Up Characteristics
    4. 8.4 Device Functional Modes
      1. 8.4.1 Disable and Enable (SYNCIN Pin)
      2. 8.4.2 Decoupling
        1. 8.4.2.1 Ripple Reduction
        2. 8.4.2.2 Connecting the DCV01 in Series
        3. 8.4.2.3 Connecting the DCV01 in Parallel
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Input Capacitor
        2. 9.2.2.2 Output Capacitor
        3. 9.2.2.3 SYNCIN Pin
        4. 9.2.2.4 PCB Design
        5. 9.2.2.5 Decoupling Ceramic Capacitors
        6. 9.2.2.6 Input Capacitor and the Effects of ESR
        7. 9.2.2.7 Ripple and Noise
          1. 9.2.2.7.1 Output Ripple Calculation Example
        8. 9.2.2.8 Dual DCV01 Output Voltage
        9. 9.2.2.9 Optimizing Performance
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Device Nomenclature
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 ドキュメントの更新通知を受け取る方法
    4. 12.4 サポート・リソース
    5. 12.5 Trademarks
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 用語集
  13. 13Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

Input Capacitor and the Effects of ESR

If the input decoupling capacitor is not ceramic (and has an ESR greater than  20 mΩ), then at the instant the power transistors switch on, the voltage at the input pins falls momentarily. If the voltage falls below approximately 4 V, the DCV01 detects an undervoltage condition and switches the DCV01 drive circuits to a momentary off state. This detection is carried out as a precaution against a genuine low input voltage condition that could slow down or even stop the internal circuits from operating correctly. A slow-down or stoppage results in the drive transistors being turned on too long, causing saturation of the transformer and destruction of the device.

Following detection of a low input voltage condition, the device switches off the internal drive circuits until the input voltage returns to a safe value, at which time the device tries to restart. If the input capacitor is still unable to maintain the input voltage, shutdown recurs. This process repeats until the input capacitor charges sufficiently to start the device correctly.

Normal start-up must occur in approximately 1 ms after power is applied to the device. If a considerably longer start-up duration time is encountered, it is likely that either (or both) the input supply or the capacitors are not performing adequately.

For 5-V to 15-V input devices, a 2.2-µF, low-ESR ceramic capacitor ensures a good start-up performance. For
24-V input voltage devices, TI recommends 0.47-µF ceramic capacitors. Tantalum capacitors are not recommended, because most do not have low-ESR values and will degrade performance. If tantalum capacitors must be used, designers must pay close attention to both the ESR and voltage as derated by the vendor.

Note:

During the start-up period, these devices can draw maximum current from the input supply. If the input voltage falls below approximately 4 V, the devices may not start up. Connect a 2.2-µF ceramic capacitor close to the input pins.