A Novel High-Order Temporal Moving Average Filter in Sampler-Based Discrete-Time Receiver

Abstract

A discrete-time (DT) filter with high-order temporal moving average (TMA) by actively-weighted charge sampling is proposed. The weight of sampled charge can be effectively controlled by digitally-controlled variable operational transconductance amplifier (OTA). By switching the control transistors of the OTA, the transconductance can be changed according to the desired weight ratio. Therefore, high-order TMA operation can be possible. It has small size, increased voltage gain, and low parasitic effects. The suggested high-order TMA filter is implemented in the TSMC 0.18 μm CMOS process. DC current is about 9.7 mA.