Analog Devices, Inc.
Correlated double sampling amplifier for low power

Abstract:

A signal acquisition or conditioning amplifier can be configured and controlled to use correlated doubling sampling (CDS) of a differential input signal, and a storage capacitor in a capacitive or other feedback network, a low power operational transconductance amplifier (OTA) capable of being powered down between CDS samplings, and which can be operated in a manner that provides good performance characteristics while still providing low or efficient power consumption. The amplifier and other signal processing circuitry can allow power to be scaled down, when less signal measurement throughput is needed, and to be scaled up, when more signal measurement throughput is needed. Such flexibility can help make the present approach useful for a wide range of signal acquisition and measurement applications. Precharging via buffer amplifiers can provide improved signal acquisition circuitry effective input impedance.