SGLS178J August   2003  – January 2026 LM2902-Q1 , LM2902B-Q1 , LM2902BA-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configurations 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 - LM2902B-Q1 and LM2902BA-Q1
    6. 5.6 Electrical Characteristics: LM2902-Q1, LM2902KV-Q1, LM2902KAV-Q1
    7. 5.7 Operating Conditions: LM2902-Q1, LM2902KV-Q1, LM2902KAV-Q1
    8. 5.8 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input Common-Mode Range
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.2 Detailed Design Procedure

Determine the gain required by the inverting amplifier using Equation 1 and Equation 2:

Equation 1. LM2902-Q1 LM2902B-Q1 LM2902BA-Q1
Equation 2. LM2902-Q1 LM2902B-Q1 LM2902BA-Q1

Once the desired gain is determined, choose a value for RI or RF. Choosing a value in the kilohm range is desirable because the amplifier circuit uses currents in the milliampere range. This allows the part to not draw too much current. This example uses 10kΩ for RI which means 36kΩ is used for RF. This was determined by Equation 3.

Equation 3. LM2902-Q1 LM2902B-Q1 LM2902BA-Q1