Résumé
A method for enhancing the noise-power tradeoff of front-end amplifiers in parallel recording applications is proposed. The circuit uses shared-input transconductance amplifiers and differential readout to attenuate correlated noise between parallel outputs, resulting in significant supply current savings without noise penalty. Also, a method for reducing the remaining noise with little power penalty is proposed. The potential benefits of combining both methods and the related trade-offs are discussed and validated by simulations on a sample design intended for ENG recordings, using models of a 0.35µm BiCMOS process. It is shown that the total supply current can be reduced by more than 50% that of a comparable system using conventional differential amplifiers with equivalent output noise. Alternatively, the noise can be reduced by approximately 35% with comparable power consumption.