Minimizing cross-talk for multi-channels VLSI analog chips

In this work, a quad instrumentation amplifier was designed for optimum crosstalk reduction. The chip was designed for a multichannel data acquisition cardiac diagnostic system that requires high attenuation of the crosstalk between channels. Since the crosstalk problem was related to parasitic bipolar junction transistors between the inputs of the differential amplifiers, an approach was followed to isolate the input terminals using quad rings. These rings work as dummy collectors to collect minority carriers injected from the input terminals (emitters) and collected by the other input terminals (collectors). In this work, four different chips were designed and tested, one of which to test the design of a single instrumentation amplifier against the simulation and calculated performance. The design considers /spl plusmn/2.5 V power supplies for minimum power consumption. Common-mode rejection, power supply sensitivity, and chip size were of parameter interest. Crosstalk attenuation in excess of 90 dB was recorded between channels.