Patent Number: 6,167,242

Title: Offset voltage cancellation system for radio frequency power controllers

Abstract: The invention provides RF power controllers that cancel offset voltages in the power control loop and external offset voltages by coupling the output of the RF power controller to an auto-zero amplifier during STANDBY mode. The auto-zero amplifier controls the output voltage of the RF power controller during each STANDBY mode so as to eliminate the effect of offset voltages. The voltage at the input of the auto-zero amplifier that allows the offset voltages to be canceled is stored during ENABLE mode. The stored voltage is used by the auto-zero amplifier to continue to remove the effect of the offset voltages on the output voltage of the RF power controller during ENABLE mode. Offset drifts due to temperature, power supply changes, etc. are canceled due to frequent offset sampling.

Inventors: Henderson; Edward L. (Atkinson, NH), Bell; David B. (Los Altos, CA)

Assignee: Linear Technology Corporation

International Classification: H03F 1/30 (20060101); H03G 3/30 (20060101); H04B 001/04 ()

Expiration Date: 12/26/2017