Broadcom Corporation

Wynstan Tong

Chun-Ying Chen

Todd Lee Brooks

Michael Q Le

Jungwoo Song

Hui Pan

Kwang Young Kim

A method and apparatus to counter effects of an offset voltage by calibrating an analog-to-digital converter (ADC). A digital calibration loop minimizes the effects of offset voltage to improve ADC accuracy as well as provide a low-power, submicron-scale ADC. A calibration circuit senses an ADC output and adjusts a variable calibration voltage to counter the effects of the offset voltage. Reduction of the offset voltage effects increases the ADC accuracy.

Digital calibration loop for an analog to digital converter

A low noise transconductance cell includes a resistor and a differential circuit pair having two equivalent half-circuits. Each half-circuit includes a feedback loop coupled to the resistor. The feedback loop includes an input transistor coupled to an inverting gain stage. The inverting gain stage is coupled to an output transistor which in turn is coupled to the input transistor and the resistor. In a low noise transconductance cell, a bias current source is coupled to the center of series connected resistors. In a high swing transconductance cell, a first bias current source is coupled to the left terminal of a resistance stage and a second bias current source is coupled to the right terminal of the resistance stage. The resistance stage can include a single resistor or a plurality of resistors.

Linear low noise transconductance cell

Growing community of inventors

Irvine, CA, United States of America

Wynstan Tong