Gilbert-Multiplier-Based Parallel 1-D and 2-D Analog FIR Filters for Medical Diagnostics

A novel idea and CMOS implementation of power-efficient 1-D and 2-D finite-impulse-response (FIR) filters based on a current-mode Gilbertvector- multiplier (GVM) have been proposed. MOS transistors included in the GVM multiplier work in a weak inversion resulting in an ultra low power consumption, with currents as low as several hundred nanoAmps to several micro- Amps. Due to the proposed multiplier, all output samples of the FIR filters can be calculated in parallel, making the filtration operation very fast. Moreover, the GVM enables a simple normalization of the output samples. As a consequence, not current values but current ratio values are significant here. As an example, a time-domain 1-D 3rd order filter has been presented which dissipates 8-μW of power enabling a 2-MHz sampling frequency (fS). Another example is a 2-D filter with the frame resolution of 6x1 pixels that dissipates 7-μW at the data rate of 1 Mframe/s.