Differential optocoupler amplifier with low noise, low power and balanced output

Abstract

An optocoupler with differential input and balanced output was realized to make galvanic decoupling of a particle detector located in a high common mode disturbance environment. The circuit configuration incorporates a true differential optocoupled feedback, with low bias current in LEDs and photodiodes. The present circuit improves by a factor two the dynamic range of a previous solution. Large Common Mode (CMRR) and Power Supply (PSRR) Rejection Ratio, low crossover distortion, high dynamic range, low noise and power dissipation have been achieved.