Differential cascode magneto-resistance preamplifier with bias bypass

摘要

A high-gain, high-bandwidth, low-noise differential common-emitter-common-base cascode preamplifier for use in the read circuitry of an MR head system includes a by-pass circuitry. Currents generated in load devices connected to the preamplifier are added to currents generated in the by-pass circuitry to provide the currents that flow through the common-emitter transistors of the preamplifier.