SNVS671F February   2011  – May 2019 LM21212-1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Application Circuit
  4. 4 Revision History
  5. 5 Description
  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 Performance Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Frequency Synchronization
      2. 8.3.2 Precision Enable
      3. 8.3.3 UVLO
      4. 8.3.4 Current Limit
      5. 8.3.5 Short-Circuit Protection
      6. 8.3.6 Thermal Protection
      7. 8.3.7 Power-Good Flag
      8. 8.3.8 Light Load Operation
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Detailed Design Procedure
        1. 9.2.1.1 Custom Design With WEBENCH® Tools
        2. 9.2.1.2 Output Voltage
        3. 9.2.1.3 Precision Enable
        4. 9.2.1.4 Soft Start
        5. 9.2.1.5 Inductor Selection
        6. 9.2.1.6 Output Capacitor Selection
        7. 9.2.1.7 Input Capacitor Selection
        8. 9.2.1.8 Control Loop Compensation
      2. 9.2.2 Application Curves
  10. 10Layout
    1. 10.1 Pcb Layout Considerations
    2. 10.2 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With Webench® Tools
    2. 11.2 Receiving Notification Of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, And Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.3.2 Precision Enable

The enable (EN) pin allows the output of the device to be enabled or disabled with an external control signal. This pin is a precision analog input that enables the device when the voltage exceeds 1.35V (typical). The EN pin has 110 mV of hysteresis and will disable the output when the enable voltage falls below 1.24V (typical). If the EN pin is not used, it can be left open, and will be pulled high by an internal 2 µA current source. Since the enable pin has a precise turn-on threshold it can be used along with an external resistor divider network from VIN to configure the device to turn-on at a precise input voltage.