SBOA601 January   2025 LOG200

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Critical Photodiode Specifications
  6. 3Interfacing the LOG200 With the Photosensor
    1. 3.1 Photodiode Connections
    2. 3.2 Photodiode Adaptive Biasing Current Output
  7. 4Optical Bench for Current Sensing Measurements
    1. 4.1 Transient Response with Photosensor
  8. 5Optical Power Measurements with the LOG200
  9. 6Error Sources and Uncalibrated Error Analysis
  10. 7Auxiliary Op Amp Circuits
    1. 7.1 Single-Ended to Differential Conversion Circuit
    2. 7.2 Sallen-Key Low-Pass Filter
  11. 8Summary
  12. 9References

7 Auxiliary Op Amp Circuits

The LOG200 features an additional wide-bandwidth auxiliary amplifier. The amplifier can be used to perform scaling gain functions, filtering functions and single-ended to differential conversion circuts. This section contains an example for single-ended to differential conversion, and a low-pass Sallen-Key filtering application.

Do not use the auxiliary amplifier as a comparator, as the input pins of the auxiliary op-amp are protected from excessive differential voltage with an internal clamp built with back-to-back diodes. The op-amp is not intended to withstand a continuous differential voltage. For more information, refer to the auxiliary amplifier input voltage specifications on the Absolute Maximum Ratings table of the LOG200 data sheet.