Rambus Inc. collects two more patents

United States Patent 7,057,460

Kaviani, et al. June 6, 2006

Differential amplifier with adaptive biasing and offset cancellation

Abstract
A differential amplifier with adaptive biasing and offset cancellation is disclosed. In one particular exemplary embodiment, the differential amplifier may comprise a first electrical path comprising a first transistor and a first resistance element, and a second electrical path comprising a second transistor and a second resistance element, where the first and the second electrical paths are coupled to a voltage source on one end and to a current source on the other end. The differential amplifier may further comprise a first adjustable current source coupled between the voltage source and a first node located between the first transistor and the first resistance element, and a second adjustable current source coupled between the voltage source and a second node located between the second transistor and the second resistance element, wherein the first and second adjustable current sources provide biasing currents for the two electrical paths.

Inventors: Kaviani; Kambiz (Palo Alto, CA); Chang; Kun-Yung (Los Altos, CA); Abhyankar; Abhijit (Sunnyvale, CA)

Assignee: Rambus, Inc. (Los Altos, CA)

Appl. No.: 878441

Filed: June 29, 2004

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Updated to include second patent 6/7/06

United States Patent 7,054,771

Batra, et al. May 30, 2006

Bus line current calibration

Abstract
Disclosed herein is a method and system for calibrating line drive currents in systems that generate data signals by varying line drive currents and that interpret the data signals by comparing them to one or more reference voltages. The calibration includes varying the line drive current at a transmitting component. At different line drive currents, a receiver reference voltage is varied while the transmitting component transmits data to a receiving component. At each line drive current, the system records the highest and lowest receiver reference voltages at which data errors do not occur. The system then examines the recorded high and low receiver reference voltages to determine a desirable line drive current.

Inventors: Batra; Pradeep (Santa Clara, CA); Rutkowski; Rick A. (Sunnyvale, CA)

Assignee: Rambus, Inc. (Los Altos, CA)

Appl. No.: 068260

Filed: February 28, 2005

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