SNVS007H september   1998  – june 2023 LM2676

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Description (continued)
  7. 6 Pin Configuration and Functions
  8. 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 – 3.3-V Version
    6. 7.6  Electrical Characteristics – 5-V Version
    7. 7.7  Electrical Characteristics – 12-V Version
    8. 7.8  Electrical Characteristics – Adjustable Voltage Version
    9. 7.9  Electrical Characteristics – All Output Voltage Versions
    10. 7.10 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Adjustable Output Voltage
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Active Mode
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Fixed Output Voltage Typical Application
        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 Inductor Selection (L1)
          3. 9.2.1.2.3 Output Capacitor Selection (COUT)
          4. 9.2.1.2.4 Catch Diode Selection (D1)
          5. 9.2.1.2.5 Input Capacitor (CIN)
          6. 9.2.1.2.6 Boost Capacitor (CB)
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Adjustable Output Voltage Typical Application
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Programming Output Voltage
          2. 9.2.2.2.2 Inductor Selection (L1)
          3. 9.2.2.2.3 Output Capacitor Selection (COUT)
          4. 9.2.2.2.4 Catch Diode Selection (D1)
          5. 9.2.2.2.5 Input Capacitor (CIN)
          6. 9.2.2.2.6 Boost Capacitor (CB)
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Typical Application for All Output Voltage Versions
        1. 9.2.3.1 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 WSON Package Devices
      2. 9.4.2 Layout Examples
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 Custom Design with WEBENCH® Tools
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.2.2.1 Programming Output Voltage

Select R1 and R2, as shown in Figure 9-5.

Use the following formula to select the appropriate resistor values.

Equation 1. GUID-971C342C-AE4E-4E7F-A133-569DC3A9C581-low.png

where

  • VREF = 1.21 V

Select a value for R1 between 240 Ω and 1.5 kΩ. The lower resistor values minimize noise pickup in the sensitive feedback pin. (For the lowest temperature coefficient and the best stability with time, use 1% metal film resistors.)

Equation 2. GUID-2E5DA7A6-FA94-4BA0-B756-889C5C785353-low.png

Select R1 to be 1 kΩ, 1%. Solve for R2.

Equation 3. GUID-D0D93358-4B07-4143-8EA0-3A9E20645ABF-low.png

where

  • R2 = 1k (16.53 − 1) = 15.53 kΩ, closest 1% value is 15.4 kΩ
    R2 = 15.4 kΩ