Patent ID: 6870696
Filing Date: 2005-03-22
Classification: G11B

Abstract:
1. A preamplifier system, comprising: a magneto-resistive (MR) sensor; an alternating current (AC) coupling module coupled to the MR senior for blocking a direct current (DC) voltage associated with an input signal, and filtering low frequency noise associated with the input signal; a gain stage module coupled to the AC coupling module, the gain stage module including a plurality of cascade field effect transistors (FETs) configured for amplifying the input signal, while reducing intrinsic noise and increasing operational bandwidth; wherein the gain stage module includes a first transistor including a source terminal coupled to ground, a gate terminal, and a drain terminal; a second transistor including a source terminal coupled to the drain terminal of the first transistor, a gate terminal, and a drain terminal coupled to the output of the gain stage module.