SLOSEG0A November   2025  – November 2025 LOG305

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 Log Detector 
    6. 5.6 Typical Characteristics: VCC = 3.6V
    7. 5.7 Typical Characteristics: VCC = 5.25V
  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 Output Gain
    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 Energy Detection
        1. 8.2.1.1 Detailed Design Procedure
        2. 8.2.1.2 Application Curves
    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 Third-Party Products Disclaimer
    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

7.3.1 Output Gain

The LOG305 includes an internal amplifier that enables gain adjustment. The VDET node internal to the LOG305 swings maximum up to 2.25V for the full scale input voltage range, refer Figure 5-1. The maximum voltage on VDET is restricted to 2.25V irrespective of the supply voltage. When operating LOG305 on higher supply voltages like 3.3V or 5V, adjust the gain of the internal op-amp by selecting the appropriate values of the feedback resistor R1 and R2 to gain the output swing. This enables the output stage to utilize the complete supply rail while maintaining the dynamic input range of 18μVRMS to 1VRMS.

Beside helping gain the output signals, the integrated op-amp has a short circuit protection. The wide-bandwidth low-output impedance, output stage, of the op-amp enables driving ADCs directly.

LOG305 Gain Adjustment Control Figure 7-1 Gain Adjustment Control