American Journal of Electrical and Electronic Engineering. 2014, 2(6), 159-164DOI:
Abstract: In this paper, a digitally controlled single input multi output current-mode K.H.N. Biquad Filter is presented. The filter circuit is composed of three DVCCs together with four grounded resistors and two grounded capacitors. The digital control is incorporated using a current-summing network (CSN). Tuning of resonant frequency is carried out by 3–bit digital control word. Block by block replacement has been done to observe the change in the relationship between resonant frequency of the band-pass filter with the control word. The filter circuit showed three different variations when the DVCC blocks were replaced (one by one) with 3-bit DC-DVCC blocks. PSPICE simulations using TSMC 0.25 micron CMOS technology have been performed to validate the theoretical results.