Preamplifier of a signal from a variable resistance sensor, and a current source

摘要

A preamplifier provides an output signal which follows a varying resistance of a sensor of a condition or parameter. An example sensor is a magneto-resistive head employed in computer mass storage systems to read magnetic signals recorded on a magnetic tape or disk. The preamplifier uses a current-mode amplifier to increase its bandwidth and reduce signal distortion. A current source, used with the preamplifier or some other circuit, includes a low pass filter to reduce the effects of various noise sources.