JAJSMN8D December   2000  – August 2021 DCR021205 , DCR022405

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  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 Isolation
        1. 7.3.1.1 Operation or Functional Isolation
        2. 7.3.1.2 Basic or Enhanced Isolation
        3. 7.3.1.3 Working Voltage
        4. 7.3.1.4 Isolation Voltage Rating
        5. 7.3.1.5 Repeated High-Voltage Isolation Testing
      2. 7.3.2 Power Stage
      3. 7.3.3 Oscillator and Watchdog
      4. 7.3.4 ERROR Flag
      5. 7.3.5 Synchronization
      6. 7.3.6 Construction
      7. 7.3.7 Decoupling – Ripple Reduction
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Disable and Enable
      2. 7.4.2 Regulated Output Disable and Enable
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 DCR02 Single Voltage Output
      2. 8.1.2 Generating Two Positive Output Voltages
      3. 8.1.3 Generation of Dual Polarity Voltages from Two Self-Synchronized DCR02s
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Input Capacitor
        2. 8.2.2.2 Output Capacitor
        3. 8.2.2.3 Filter Capacitor
        4. 8.2.2.4 ERROR Flag
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
    3. 10.3 Thermal Consideration
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 サポート・リソース
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, 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

7.3.7 Decoupling – Ripple Reduction

Due to the very low forward resistance of the DMOS switching transistors, high current demands are placed upon the input supply for a short time. By using a high-quality, low Equivalent Series Resistance (ESR) ceramic input capacitor of 2.2-µF, placed close to the IC supply input pins, the effects on the power supply can be minimized.

The high switching frequency of 400 kHz allows relatively small values of capacitors to be used for filtering the rectified output voltage. A good-quality, low-ESR, 1-µF ceramic capacitor placed close to the VREC pin and output ground is required and reduces the ripple. The output at VREC is full wave rectified and produces a ripple of 800 kHz.

TI recommends that a 0.1-µF, low-ESR ceramic capacitor is connected close to the output pin and ground to reduce noise on the output. The capacitor values listed are minimum values. If lower ripple is required, the filter capacitor must be increased in value to 2.2 µF.

As with all switching power supplies, the best performance is obtained with low ESR ceramic capacitors connected close to the device pins. If low-ESR ceramic capacitors are not used, the ESR generates a voltage drop when the capacitor is supplying the load power. Often a larger capacitor is chosen for this purpose, when a low ESR, smaller capacitor would perform as well.

Note:

TI does not recommend that the DCR02 be fitted using an IC socket, as this degrades performance.