ZHCSJV7D July   2005  – June 2019 TPS40190

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      简化应用示意图
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Dissipation Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Electrical Characteristics
    5. 6.5 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 Internally Fixed Parameters
      2. 7.3.2 Output Short Circuit Protection
      3. 7.3.3 Enable Functionality
      4. 7.3.4 5-V Regulator
      5. 7.3.5 Startup Sequence and Timing
      6. 7.3.6 Prebias Outputs
  8. 8 Application and Implementation
    1. 8.1 Typical Applications
  9. 9 器件和文档支持
    1. 9.1 文档支持
      1. 9.1.1 相关文档
    2. 9.2 接收文档更新通知
    3. 9.3 社区资源
    4. 9.4 商标
    5. 9.5 静电放电警告
    6. 9.6 Glossary
  10. 10机械、封装和可订购信息

封装选项

请参考 PDF 数据表获取器件具体的封装图。

机械数据 (封装 | 引脚)
  • DRC|10
散热焊盘机械数据 (封装 | 引脚)
订购信息

7.3.6 Prebias Outputs

Some applications require that the converter not sink current during start-up if a pre-existing voltage is higher than the output. Because synchronous buck converters inherently sink current some method of overcoming this characteristic must be employed. Applications that require this operation are typically power rails for a multi supply processor or ASIC. The method used in this controller, is to not allow the low side or rectifier FET to turn on until there the output voltage commanded by the start up ramp is higher than the pre-existing output voltage. This is detected by monitoring the internal pulse width modulator (PWM) for its first output pulse. Because this controller uses a closed loop startup, the first output pulse from the PWM does not occur until the output voltage is commanded to be higher than the pre-existing voltage. This effectively limits the controller to sourcing current only during the startup sequence.

If the pre-existing voltage is higher than the intended regulation point for the output of the converter, the converter starts and sinks current when the soft-start time has completed. A typical pre-biased start-up is shown in Figure 28.

TPS40190 startup_lus658.gifFigure 27. TPS40190 Start-up Timing
TPS40190 prebias_lus658.gifFigure 28. Prebiased Start-up Timing