ZHCSEU9C March   2016  – June 2018 LMZ34202

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      简化应用
      2.      效率与输出电流间的关系
  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 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
    8. 6.8 Typical Characteristics (Thermal Derating)
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Switching Frequency (RT)
      3. 7.3.3  Recommended Operating Range
      4. 7.3.4  Synchronization (CLK)
      5. 7.3.5  Output Capacitor Selection
      6. 7.3.6  VERSA-COMP Pin Configurations
      7. 7.3.7  Input Capacitor Selection
      8. 7.3.8  Output On/Off Inhibit (INH/UVLO)
      9. 7.3.9  Under Voltage Lockout (UVLO)
      10. 7.3.10 Remote Sense
      11. 7.3.11 VBSEL
      12. 7.3.12 Soft-Start (SS/TR)
      13. 7.3.13 Power Good (PWRGD) and Pull-up (PWRGD_PU)
      14. 7.3.14 Overcurrent Protection
      15. 7.3.15 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Light Load Operation
      3. 7.4.3 Shutdown Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Minimum External Component Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Output Voltage Set-Point
          3. 8.2.1.2.3 RT and RTSEL
          4. 8.2.1.2.4 VERSA-COMP
          5. 8.2.1.2.5 VBSEL
          6. 8.2.1.2.6 Input Capacitors
          7. 8.2.1.2.7 Output Capacitors
        3. 8.2.1.3 Application Curves
      2. 8.2.2 INH Control Application
        1. 8.2.2.1 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Switching Frequency
        2. 8.2.3.2 Power Good
        3. 8.2.3.3 Inhibit Control
        4. 8.2.3.4 VERSA-COMP
        5. 8.2.3.5 VBSEL
        6. 8.2.3.6 Soft-Start Capacitors
        7. 8.2.3.7 Input Capacitors
        8. 8.2.3.8 Output Capacitors
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 EMI
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 开发支持
        1. 11.1.1.1 使用 WEBENCH® 工具创建定制设计
      2. 11.1.2 第三方产品免责声明
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 术语表
  12. 12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

7.3.8 Output On/Off Inhibit (INH/UVLO)

The INH/UVLO pin provides on and off control of the device. The INH input provides a precise 2.1 V rising threshold to allow direct logic drive or connection to a voltage divider from a higher voltage source such as PVIN. Once the INH/UVLO pin voltage exceeds the threshold voltage, the device starts operation. The INH input also incorporates 300 mV (typ) of hysteresis resulting in a falling threshold of 1.8 V. If the INH/UVLO pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low quiescent current state. The INH/UVLO pin cannot be open circuit or floating. The simplest way to enable the operation of the LMZ34202 is to connect the INH/UVLO pin to PVIN pin directly as shown in Figure 20. This connection allows the LMZ34202 device to restart when PVIN is again within the operation range.

If an application requires controlling the INH/UVLO pin, either drive it directly with a logic input or use an open drain and collector device to interface with the pin and place a 100-kΩ resistor between this pin and PVIN pin as shown in Figure 21. When turning Q1 on applies a low voltage to the inhibit control (INH/UVLO) pin and disables the output of the supply, shown in Figure 22. If Q1 is turned off, the supply executes a soft-start power-up sequence, as shown in Figure 23.

LMZ34202 LMZ33603_Enable.gifFigure 20. Enabling the Device
LMZ34202 LMZ33603_INHcontrol.gifFigure 21. Typical Inhibit Control
LMZ34202 inhoff.pngFigure 22. Inhibit Turn-Off
LMZ34202 inhon.pngFigure 23. Inhibit Turn-On