SNVS581M February   2013  – October 2020 LM22679 , LM22679-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings: LM22679
    3. 6.3 Handling Ratings: LM22679-Q1
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Thermal Information
    6. 6.6 Electrical Characteristics
    7. 6.7 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 UVLO
      2. 7.3.2 Soft-Start
      3. 7.3.3 Bootstrap Supply
      4. 7.3.4 Internal Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 Current Limit
      4. 7.4.4 Current Limit Adjustment
      5. 7.4.5 Thermal Protection
      6. 7.4.6 Duty-Cycle Limits
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Output Voltage Divider Selection
      2. 8.1.2 Power Diode
    2. 8.2 Typical Application
      1. 8.2.1 Typical Buck Regulator Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 External Components
          2. 8.2.1.2.2 Inductor
          3. 8.2.1.2.3 Input Capacitor
          4. 8.2.1.2.4 Output Capacitor
          5. 8.2.1.2.5 Bootstrap Capacitor
        3. 8.2.1.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Support Resources
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Trademarks
    5. 11.5 Glossary
    6. 11.6 Electrostatic Discharge Caution

Package Options

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

3 Description

The LM22679 switching regulator provides all of the functions necessary to implement an efficient high-voltage step-down (buck) regulator using a minimum of external components. This easy-to-use regulator incorporates a 42-V N-channel MOSFET switch that can provide up to 5 A of load current. Excellent line and load regulation along with high efficiency (> 90%) are featured. Voltage mode control offers short minimum on-time, allowing the widest ratio between input and output voltages. Internal loop compensation means that the user is free from the tedious task of calculating the loop compensation components. Fixed 5-V output and adjustable output voltage options are available. A switching frequency of 500 kHz allows for small external components and good transient response. An adjustable soft-start feature is provided through the selection of a single external capacitor. In addition, the switch-current limit can be programmed with a single external resistor, allowing solution optimization. The LM22679 device also has built-in thermal shutdown and current limiting to protect against accidental overloads.

The new product, LM61460, offers higher efficiency, lower stand-by quiescent current, and improved EMI performance. See the device comparison table to compare. Start WEBENCH design with LM61460

The LM22679 device is a member of Texas Instruments' SIMPLE SWITCHER® family. The SIMPLE SWITCHER concept provides for an easy to use complete design using a minimum number of external components and the TI WEBENCH design tool. TI's WEBENCH tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in.

Device Information
PART NUMBER PACKAGE(1) BODY SIZE (NOM)
LM22679 TO-263 (7) 10.16 mm x 9.85 mm
LM22679-Q1
(1) For all available packages, see the orderable addendum at the end of the data sheet.
GUID-F4885512-7424-4AE4-8212-F4D1B5F3DC2D-low.gif Simplified Application Schematic