A fiber-optic analog isolator of up to 10 MHz bandwidth

In order to reduce the effect of EMI and enhance signal to noise ratio (SNR), a fiber-optic high speed isolator has been designed. Each channel of the isolator has a transmitter unit connected via fiber-optic cable to the receiver unit.

A transmitter unit consists of a 6th order Bessel low-pass anti-aliasing filter, an analog-to-digital converter (ADC), a Field Programmable Gate Array (FPGA), a serializer and an optical transceiver, while a receiver unit comprises an optical transceiver, a deserializer, a FPGA, a digital–to-analog converter (DAC) and a 6th order Bessel low-pass filter. Data from the ADC is serialized by the serializer using 8B/10B encoding before transmission, and 10B/8B decoding was used by the deserializer in the receiver unit.