JAJSF35D September   2017  – October 2019 TPS50601A-SP

PRODUCTION DATA.  

  1. 特長
    1.     VIN=PVIN=5Vでの効率
  2. アプリケーション
  3. 概要
  4. 改訂履歴
  5. 概要(続き)
  6. Pin Configuration and Functions
    1.     Pin 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 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  VIN and Power VIN Pins (VIN and PVIN)
      2. 8.3.2  Voltage Reference
      3. 8.3.3  Adjusting the Output Voltage
      4. 8.3.4  Safe Start-Up Into Prebiased Outputs
      5. 8.3.5  Error Amplifier
      6. 8.3.6  Slope Compensation
      7. 8.3.7  Enable and Adjust UVLO
      8. 8.3.8  Adjustable Switching Frequency and Synchronization (SYNC)
      9. 8.3.9  Slow Start (SS/TR)
      10. 8.3.10 Power Good (PWRGD)
      11. 8.3.11 Sequencing (SS/TR)
      12. 8.3.12 Output Overvoltage Protection (OVP)
      13. 8.3.13 Overcurrent Protection
        1. 8.3.13.1 High-Side MOSFET Overcurrent Protection
        2. 8.3.13.2 Low-Side MOSFET Overcurrent Protection
      14. 8.3.14 Thermal Shutdown
      15. 8.3.15 Turn-On Behavior
      16. 8.3.16 Small Signal Model for Frequency Compensation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Fixed-Frequency PWM Control
      2. 8.4.2 Continuous Current Mode (CCM) Operation
  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 Operating Frequency
        2. 9.2.2.2 Output Inductor Selection
        3. 9.2.2.3 Output Capacitor Selection
        4. 9.2.2.4 Slow Start Capacitor Selection
        5. 9.2.2.5 Undervoltage Lockout (UVLO) Set Point
        6. 9.2.2.6 Output Voltage Feedback Resistor Selection
        7. 9.2.2.7 Compensation Component Selection
      3. 9.2.3 Parallel Operation
      4. 9.2.4 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 ドキュメントのサポート
      1. 12.1.1 関連資料
    2. 12.2 ドキュメントの更新通知を受け取る方法
    3. 12.3 コミュニティ・リソース
    4. 12.4 商標
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13メカニカル、パッケージ、および注文情報

Small Signal Model for Frequency Compensation

The device uses a transconductance amplifier for the error amplifier and readily supports two of the commonly used frequency compensation circuits shown in Figure 22. In Type 2A, one additional high-frequency pole is added to attenuate high-frequency noise.

The following design guidelines are provided for advanced users who prefer to compensate using the general method. The step-by-step design procedure described in Detailed Design Procedure may also be used.

TPS50601A-SP f_compen_lvsa94.gifFigure 22. Types of Frequency Compensation

The general design guidelines for device loop compensation are as follows:

  1. Determine the crossover frequency fco. A good starting point is one-tenth of the switching frequency, ƒSW.
  2. R3 can be determined by:
  3. Equation 10. TPS50601A-SP eq_comp1.gif

    where gmea is the gm of the error amplifier (1400 μS), gmps is the gm of the power stage (22 S) and VREF is the reference voltage (0.804 V).

  4. Place a compensation zero at the dominant pole TPS50601A-SP eq_comp2.gif using C1 and R3.
    C1 can be determined by
  5. Equation 11. TPS50601A-SP eq_comp3.gif
  6. C2 is optional. It can be used to cancel the zero from the equivalent series resistance (ESR) of the output capacitor COUT.
  7. Equation 12. TPS50601A-SP eq_comp4.gif