Low noise preamplifier
US6054901A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1997 |
| Grant date | Apr 25, 2000 |
| Priority date | — |
| Expiry date | Oct 2, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A low-noise wide band preamplifier (10) provides an output voltage signal (V.sub.O) corresponding to the variation in resistance of a sensor such as Magneto-resistive (MR) head (4) which is used to read the data stored on a magnetic media. In this preamplifier, a transistor (12) and resistor (13) combination is used to function as a transimpedance amplifier (11) to increase the frequency bandwidth of the preamplifier and reduce the noise. The transimpedance amplifier (11) takes its input from an input transistor (3) coupled between the MR head (4) and a current source (2). A biasing circuit formed by a transconductance amplifier (12) and a capacitor (5) is used to control the input transistor (3) so that the average current passing through the input transistor (3) matches the current provided by the current source (2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.