Chul Jai Lee

US Patent:

7843264, Nov 30, 2010

Filed:

Jan 29, 2008

Appl. No.:

12/021477

Inventors:

Anosh B. Davierwalla - San Diego CA, US
Chul Kyu Lee - San Diego CA, US
Vannam Dang - San Diego CA, US

Assignee:

QUALCOMM, Incorporated - San Diego CA

International Classification:

H03F 3/45

US Classification:

330253, 330295, 330 9

Abstract:

An amplifier with accurate input offset voltage is described. In one design, the amplifier includes first and second unbalanced differential pairs. The first unbalanced differential pair receives a differential input signal and provides a first differential current signal. The second unbalanced differential pair receives a differential reference signal and provides a second differential current signal, which is subtracted from the first differential current signal to obtain a differential output signal. The second differential current signal tracks an error current in the first differential current signal so that the differential output signal is zero when the differential input signal is equal to a target input offset voltage for the amplifier. For each unbalanced differential pair, one transistor is M times the size of the other transistor, with M being selected to obtain the target input offset voltage.

Address:

10905 Brent Rd, Potomac, MD 20854

Phone:

(301)9831936

VIN:

5NMSG13D29H280249

Make:

HYUNDAI

Model:

SANTA FE

Year:

2009