JAJSJZ4B October   2020  – June 2024 TPS54J061

PRODUCTION DATA  

  1.   1
  2. 特長
  3. アプリケーション
  4. 概要
  5. Pin Configuration and Functions
  6. 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 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Enable and Internal LDO
      2. 6.3.2  Split Rail and External LDO
      3. 6.3.3  Output Voltage Setting
      4. 6.3.4  Soft Start and Output-Voltage Tracking
      5. 6.3.5  Frequency and Operation Mode Selection
      6. 6.3.6  D-CAP3™ Control Mode
      7. 6.3.7  Current Sense and Positive Overcurrent Protection
      8. 6.3.8  Low-side FET Negative Current Limit
      9. 6.3.9  Power Good
      10. 6.3.10 Overvoltage and Undervoltage Protection
      11. 6.3.11 Out-Of-Bounds Operation (OOB)
      12. 6.3.12 Output Voltage Discharge
      13. 6.3.13 UVLO Protection
      14. 6.3.14 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Auto-Skip Eco-Mode Light Load Operation
      2. 6.4.2 Forced Continuous-Conduction Mode
      3. 6.4.3 Pre-Bias Start-up
  8. 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  Choose the Switching Frequency and Operation Mode (MODE Pin)
        2. 7.2.2.2  Choose the Output Inductor (L)
        3. 7.2.2.3  Set the Current Limit (TRIP)
        4. 7.2.2.4  Choose the Output Capacitors (COUT)
        5. 7.2.2.5  Choose the Input Capacitors (CIN)
        6. 7.2.2.6  Feedback Network (FB Pin)
        7. 7.2.2.7  Soft Start Capacitor (SS/REFIN Pin)
        8. 7.2.2.8  EN Pin Resistor Divider
        9. 7.2.2.9  VCC Bypass Capacitor
        10. 7.2.2.10 BOOT Capacitor
        11. 7.2.2.11 Series BOOT Resistor and RC Snubber
        12. 7.2.2.12 PGOOD Pullup Resistor
      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
  9. Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 サポート・リソース
    3. 8.3 ドキュメントの更新通知を受け取る方法
    4. 8.4 Trademarks
    5. 8.5 用語集
    6. 8.6 静電気放電に関する注意事項
  10. Revision History
  11. 10Mechanical, Packaging, and Ordering 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

Choose the Input Capacitors (CIN)

The TPS54J061 requires input bypass capacitors between the VIN and PGND pins to bypass the power-stage. The bypass capacitors must be placed as close as possible to the pins of the IC as the layout will allow. At least 10-µF of ceramic capacitance and a 0.01-µF to 0.1-µF high frequency ceramic bypass capacitor is required. The high frequency bypass capacitor minimizes high frequency voltage overshoot across the power-stage. The ceramic capacitors must be high-quality dielectric of X5R or X7R for the high capacitance-to-volume ratio and stable characteristics across temperature. In addition to this, more bulk capacitance can be needed on the input depending on the application to minimize variations on the input voltage during transient conditions.

The input capacitance required to meet a specific input ripple target can be calculated with Equation 23. A recommended target input voltage ripple is 5% the minimum input voltage, 400-mV in this example. The calculated input capacitance is 2.4 µF and the minimum input capacitance of 10 µF exceeds this. This example meets these two requirements with two 4.7-µF 0603 25-V ceramic capacitors and two 10-µF 1206 25-V ceramic capacitors.

Equation 23. TPS54J061

The capacitor must also have an RMS current rating greater than the maximum input RMS current in the application. The input RMS current the input capacitors must support is calculated by Equation 24 and is 2.5 A in this example. The ceramic input capacitors have a current rating much greater than this.

Equation 24. TPS54J061

For applications requiring bulk capacitance on the input, such as ones with low input voltage and high current, the selection process in this article is recommended.