A Fully Differential All-pass Filter in 250nm BiCMOS Technology for Phase Shift Regulation in Dielectrophoresis Applications

A fully differential all-pass filter is designed in 250 nm BiCMOS technology with an over three decades tunable corner frequency from 50 kHz to 50 MHz. The filter provides a coarse tuning section by switching a capacitive network. Fine tuning is realized by adjusting the bias current of two operational transconductance amplifiers (OTAs) in the signal path. The overall SNDR is between 44 dB to 58 dB depending on the operational mode. Power consumption does not exceed 11.68 mW.