Programmable Gain, Temperature Compensated Logarithmic Amplifier based on Current Conveyor and OTA

Abstract

This letter reports a new logarithmic amplifier using a second generation current conveyor (CCII) and an operational trans-conductance amplifier (OTA) is presented. It utilizes the classical diode type exponential I-V relationship and allows volt- age as well as current inputs and outputs. Moreover, the proposed design does not suffer prom the presence of the instability issue of an op-amp based logarithmic amplifiers, the reason behind which lies in the presence of the active element in the feedback loop. The achieved results demonstrate logarithmic behaviour and temperature insensitivity and is in complete consonance with the theoretical postulation.