CN-0272 Circuits from the Lab™ is a reference circuit designed to solve analog, mixed-signal, and RF design challenges. The document describes the features and characteristics of products such as high-performance, 145 MHz FASTFET™ operational amplifiers, precision, selectable gain, fully differential funnel amplifiers, 12-bit, 20 MSPS, 1.8 V ADC, etc.
The document describes the CN-0272 reference circuit, a high-performance 145 MHz FASTFET operational amplifier-based photodiode preamplifier system. Designed for applications like pulse oximetry and optical sensing, it features dark current compensation using a second matched photodiode to eliminate errors caused by dark current flow in the reverse-biased diode.
The circuit provides a signal bandwidth of 2 MHz.
The AD9629-20, a 12-bit resolution and 20 MSPS sampling rate ADC, is recommended.