ZHCS760H February   2012  – June 2018 TLV62130 , TLV62130A

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      典型应用原理图
      2.      效率与输出电流间的关系
  4. 4 修订历史记录
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Enable / Shutdown (EN)
      2. 8.3.2 Soft Start / Tracking (SS/TR)
      3. 8.3.3 Power Good (PG)
      4. 8.3.4 Pin-Selectable Output Voltage (DEF)
      5. 8.3.5 Frequency Selection (FSW)
      6. 8.3.6 Undervoltage Lockout (UVLO)
      7. 8.3.7 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Pulse Width Modulation (PWM) Operation
      2. 8.4.2 Power Save Mode Operation
      3. 8.4.3 100% Duty-Cycle Operation
      4. 8.4.4 Current Limit and Short Circuit Protection
  9. 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 Custom Design With WEBENCH® Tools
        2. 9.2.2.2 Programming the Output Voltage
        3. 9.2.2.3 External Component Selection
          1. 9.2.2.3.1 Inductor Selection
          2. 9.2.2.3.2 Capacitor Selection
            1. 9.2.2.3.2.1 Output Capacitor
            2. 9.2.2.3.2.2 Input Capacitor
            3. 9.2.2.3.2.3 Soft Start Capacitor
        4. 9.2.2.4 Tracking Function
        5. 9.2.2.5 Output Filter and Loop Stability
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 LED Power Supply
      2. 9.3.2 Active Output Discharge
      3. 9.3.3 Inverting Power Supply
      4. 9.3.4 Various Output Voltages
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12器件和文档支持
    1. 12.1 器件支持
      1. 12.1.1 第三方产品免责声明
      2. 12.1.2 开发支持
        1. 12.1.2.1 使用 WEBENCH® 工具创建定制设计
    2. 12.2 接收文档更新通知
    3. 12.3 文档支持
      1. 12.3.1 相关文档
    4. 12.4 相关链接
    5. 12.5 社区资源
    6. 12.6 商标
    7. 12.7 静电放电警告
    8. 12.8 术语表
  13. 13机械、封装和可订购信息

封装选项

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

9.2.2.4 Tracking Function

If a tracking function is desired, the SS/TR pin can be used for this purpose by connecting it to an external tracking voltage. The output voltage tracks that voltage. If the tracking voltage is between 50 mV and 1.2 V, the FB pin will track the SS/TR pin voltage as described in Equation 11 and shown in Figure 6.

spacing

Equation 11. TLV62130 TLV62130A SLVSB74_eqvtr_err.gif

spacing

TLV62130 TLV62130A SLVSAG7_TRdgr.gifFigure 6. Voltage Tracking Relationship

Once the SS/TR pin voltage reaches about 1.2 V, the internal voltage is clamped to the internal feedback voltage and device goes to normal regulation. This works for rising and falling tracking voltages with the same behavior, as long as the input voltage is inside the recommended operating conditions. For decreasing SS/TR pin voltage, the device doesn't sink current from the output. So, the resulting decrease of the output voltage may be slower than the SS/TR pin voltage if the load is light. When driving the SS/TR pin with an external voltage, do not exceed the voltage rating of the SS/TR pin which is VIN + 0.3 V.

If the input voltage drops into undervoltage lockout or even down to zero, the output voltage will go to zero, independent of the tracking voltage. Figure 7 shows how to connect devices to get ratiometric and simultaneous sequencing by using the tracking function.

spacing

TLV62130 TLV62130A SLVSB74_TR.gifFigure 7. Sequence for Ratiometric and Simultaneous Startup

The resistive divider of R1 and R2 can be used to change the ramp rate of VOUT2 faster, slower or the same as VOUT1.

A sequential startup is achieved by connecting the PG pin of VOUT1 to the EN pin of VOUT2. Ratiometric start-up sequence happens if both supplies are sharing the same soft start capacitor. Equation 10 calculates the soft start time, though the SS/TR current has to be doubled. Details about these and other tracking and sequencing circuits are found in SLVA470.

Note: If the voltage at the FB pin is below its typical value of 0.8 V, the output voltage accuracy may have a wider tolerance than specified.