SNVS715B March   2011  – June 2019 LM21212-2

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, continued
  6. 6 Pin Configuration and Functions
    1.     Pin Descriptions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Ratings
    4. 7.4 Electrical Characteristics
    5. 7.5 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 Precision Enable
      2. 8.3.2 UVLO
      3. 8.3.3 Current Limit
      4. 8.3.4 Short-Circuit Protection
      5. 8.3.5 Thermal Protection
      6. 8.3.6 Power-Good Flag
      7. 8.3.7 Light Load Operation
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Typical Application 1
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 9.2.1.2.2 Output Voltage
          3. 9.2.1.2.3 Precision Enable
          4. 9.2.1.2.4 Soft Start
          5. 9.2.1.2.5 Resistor-Adjustable Frequency
          6. 9.2.1.2.6 Inductor Selection
          7. 9.2.1.2.7 Output Capacitor Selection
          8. 9.2.1.2.8 Input Capacitor Selection
          9. 9.2.1.2.9 Control Loop Compensation
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Typical Application Schematic 2
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
  10. 10Layout
    1. 10.1 Layout Considerations
    2. 10.2 Layout Example
    3. 10.3 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

5 Description, continued

The LM21212-2 is designed to work well in multi-rail power supply architectures. The output voltage of the device can be configured to track an external voltage rail using the SS/TRK pin. The switching frequency can be programmed between 300 kHz and 1.55 MHz with an external resistor.

If the output is prebiased at start-up, it does not sink current, allowing the output to smoothly rise past the prebiased voltage. The regulator is offered in a 20-pin HTSSOP package with an exposed pad that can be soldered to the PCB, eliminating the need for bulky heat sinks.