ZHCSHV9 March   2018 LMR14010A

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      简化原理图
      2.      效率与电流间的关系（rep%#402;SW= 0.7MHz，VIN = 12V，VOUT = 3.3V）
  4. 4 修订历史记录
  5. 5 Pin Configuration
    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 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 Fixed Frequency PWM Control
      2. 7.3.2 Bootstrap Voltage (CB)
      3. 7.3.3 Setting the Output Voltage
      4. 7.3.4 Enable (SHDN ) and VIN Undervoltage Lockout
      5. 7.3.5 Current Limit
      6. 7.3.6 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Continuous Conduction Mode
      2. 7.4.2 Eco-mode™
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Step-By-Step Design Procedure
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Output Inductor Selection
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 Schottky Diode Selection
        5. 8.2.2.5 Input Capacitor Selection
        6. 8.2.2.6 Bootstrap Capacitor Selection
      3. 8.2.3 Application Performance Curves
  9. 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 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. 11.2 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 Glossary
  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

7.3.4 Enable (SHDN ) and VIN Undervoltage Lockout

The LMR14010A SHDN pin is a high-voltage tolerant input with an internal pull-up circuit. The device can be enabled even if the SHDN pin is floating. The regulator can also be turned on using 1.25-V or higher logic signals. If the use of a higher voltage is desired due to system or other constraints it may be used. A 100-kΩ or larger resistor is recommended between the applied voltage and the SHDN pin to protect the device. When SHDN is pulled down to 0 V, the chip is turned off and enters the lowest shutdown current mode. In shutdown mode the supply current will be decreased to approximately 1 µA. If the shutdown function is not to be used, the SHDN pin may be tied to VIN. The maximum voltage to the SHDN pin should not exceed 40 V.

The LMR14010A has an internal UVLO circuit to shutdown the output if the input voltage falls below an internally fixed UVLO threshold level. This ensures that the regulator is not latched into an unknown state during low input voltage conditions. The regulator will power up when the input voltage exceeds the UVLO voltage level. If there is a requirement for a higher UVLO voltage, the SHDN can be used to adjust the input voltage UVLO by using external resistors.