SNVSA85D October   2015  – October 2025 LM27761

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Undervoltage Lockout
      2. 6.3.2 Input Current Limit
      3. 6.3.3 PFM Operation
      4. 6.3.4 Output Discharge
      5. 6.3.5 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Enable Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application - Regulated Voltage Inverter
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Charge-Pump Voltage Inverter
        2. 7.2.2.2 Negative Low-Dropout Linear Regulator
        3. 7.2.2.3 Power Dissipation
        4. 7.2.2.4 Output Voltage Setting
        5. 7.2.2.5 External Capacitor Selection
          1. 7.2.2.5.1 Charge-Pump Output Capacitor
          2. 7.2.2.5.2 Input Capacitor
          3. 7.2.2.5.3 Flying Capacitor
          4. 7.2.2.5.4 LDO Output Capacitor
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.2.4 Output Voltage Setting

The output voltage of the LM27761 is externally configurable. The value of R1 and R2 determines the output voltage setting. The output voltage can be calculated using Equation 5:

Equation 5. VOUT = –1.22 V × (R1 + R2) / R2

The value for R2 must be no less than 50 kΩ.