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

8.3 Power Supply Recommendations

The LOG305 has a supply voltage (VCC) biased at any voltage between 2.7V to 5.25V with respect to the VEE. Provide separate decoupling capacitors, resistors, and ferrite beads for VCC pin (see Section 8.4.2) to maintain sufficient immunity against noise coupling.

In general, an RC filter with a 10Ω in series and a 4.7μF capacitor between VCC and VEE is recommended. Additionally, a 100nF capacitor in parallel with 4.7μF capacitor placed closer to the pin, improves higher frequency rejection. The low-pass pole of this RC filter lands at approximately 3.3kHz which is sufficiently lower than the signal of interest which in case of LOG305 is 200kHz.

The general practice can be to design a low-pass filter on the supply line with a cutoff frequency lower than the incoming frequency signal by at-least a decade. An external matched band-pass filter at the Log_In pin, along with a low-pass filter on the supply pins, provides sufficient power-supply rejection to keep Log_Out unaffected.