EVAL-CN0272-SDPZ

The EVAL-CN0272-SDPZ is a circuit evaluation board for high speed photodiode signal conditioning circuit with dark current compensation. This board utilizes AD8065 high performance, 145MHz FASTFET opamp, AD8475 fully differential funnel amp, AD9629-20 12bit, 20MSPS, 1.8V ADC and ADR441 2.5V voltage reference with current sink and source. The system converts current from a high speed silicon PIN photodiode and drives the inputs of a 20MSPS analog to digital converter (ADC). This combination of parts offers spectral sensitivity from 400nm to 1050nm with 49nA of photocurrent sensitivity, a dynamic range of 91dB, and a bandwidth of 2MHz. The signal conditioning circuitry of the system consumes only 40mA of current from the ±5V supplies making this configuration suitable for portable high speed, high resolution light intensity applications, such as pulse oximetry. Other suitable applications for this circuit are as an analog optoisolator.