Method of controlling reader amplifier gain variations of a HDD preamplifier, or the like
US7085088B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 23, 2002 |
| Grant date | Aug 1, 2006 |
| Priority date | — |
| Expiry date | Jul 9, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45684
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An amplifier (70) has a differential input stage (84,86). An output transistor (102) is connected to receive a single ended output developed by transistor 86. First (74) and second (76) current sources are connected to establish respective first and second currents in the input differential transistors (84,86) according to a predetermined ratio. First and second voltages are subtracted from the differential inputs (VM,VP) in respective differential amplifiers (88,90), and the output is derived from the output transistor having a magnitude proportional to an inverse of a product of a square of the reference resistance, a carrier mobility, and an oxide capacitance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.