ZHCSHF4J May   2004  – January 2018 TPS51116

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
    1.     Device Images
      1. 3.1 典型应用
  4. 修订历史记录
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Dissipation Ratings
    5. 6.5 Thermal Information
    6. 6.6 Electrical Characteristics
    7. 6.7 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  VDDQ SMPS, Light Load Condition
      2. 7.3.2  Low-Side Driver
      3. 7.3.3  High-Side Driver
      4. 7.3.4  Current Sensing Scheme
      5. 7.3.5  PWM Frequency and Adaptive On-Time Control
      6. 7.3.6  VDDQ Output Voltage Selection
      7. 7.3.7  VTT Linear Regulator and VTTREF
      8. 7.3.8  Controling Outputs Using the S3 and S5 Pins
      9. 7.3.9  Soft-Start Function and Powergood Status
      10. 7.3.10 VDDQ and VTT Discharge Control
      11. 7.3.11 Current Protection for VDDQ
      12. 7.3.12 Current Protection for VTT
      13. 7.3.13 Overvoltage and Undervoltage Protection for VDDQ
      14. 7.3.14 Undervoltage Lockout (UVLO) Protection, V5IN (PWP), V5FILT (RGE)
      15. 7.3.15 Input Capacitor, V5IN (PWP), V5FILT (RGE)
      16. 7.3.16 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 VDDQ SMPS, Dual PWM Operation Modes
      2. 7.4.2 Current Mode Operation
      3. 7.4.3 D-CAP™ Mode Operation
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 DDR3 Application With Current Mode
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Pin Connections
        2. 8.2.2.2 Choose the inductor
        3. 8.2.2.3 Choose rectifying (low-side) MOSFET
        4. 8.2.2.4 Choose output capacitance
        5. 8.2.2.5 Determine f0 and calculate RC
        6. 8.2.2.6 Calculate CC2
        7. 8.2.2.7 Calculate CC.
        8. 8.2.2.8 Determine the value of R1 and R2.
      3. 8.2.3 Application Curves
    3. 8.3 DDR3 Application With D−CAP™ Mode
      1. 8.3.1 Design Requirements
      2. 8.3.2 Detailed Design Procedure
        1. 8.3.2.1 Pin Connections
        2. 8.3.2.2 Choose the Components
      3. 8.3.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 接收文档更新通知
    2. 11.2 社区资源
    3. 11.3 商标
    4. 11.4 静电放电警告
    5. 11.5 Glossary
  12. 12机械、封装和可订购信息

Choose output capacitance

When organic semiconductor capacitors (OS-CON) or specialty polymer capacitors (SP-CAP) are used, ESR to achieve required ripple value at stable state or transient load conditions determines the amount of capacitor(s) need, and capacitance is then enough to satisfy stable operation. The peak-to-peak ripple value can be estimated by ESR times the inductor ripple current for stable state, or ESR times the load current step for a fast transient load response. When ceramic capacitor(s) are used, the ESR is usually small enough to meet ripple requirement. In contrast, transient undershoot and overshoot driven by output capacitance becomes the key factor in determining the capacitor(s) required.