Realization of fully balanced filter using low power active inductor

A power reduction technique for a fully balanced filter is proposed. In the filter novel low power active inductors are used for the inductance simulation. In the active inductor, an output stage of a transconductor is merged with a input stage of another transconductor. Because of the merger some bias current sources can be omitted and 33% reduction in the power consumption is achieved. Moreover, the active inductor does not require common-mode feedback circuits. The proposed power reduction technique makes a sacrifice of a common-mode rejection ratio (CMRR). An input stage which enhances a CMRR of a filter is also introduced to obtain an adequate common mode rejection. A filter using the proposed low power active inductor and the input stage achieves about -46 dB common-mode gain even when more than 33% reduction in power consumption is observed.