Frequency Response of Electronically Tunable Current-Mode Third Order High Pass and Low Pass Filter for Q = 10

The circuits using current-mode (CM) building blocks have received considerable attention in many filtering and signal processing applications. Compared to their voltage-mode(VM) counterparts, the current-mode building blocks are attractive because of their wider bandwidth, higher slew rate, and lower power consumptions. In IC technology, it is desirable to operate circuits at low voltages which can be achieved by using CM building blocks. As a large number of op-amp based circuits with elegant realization procedures are already available, it is worthwhile to convert them into the circuits based on current-mode building blocks. In this paper, a realization of a current mode third order high pass and low pass filter is described. The proposed circuit employs operational amplifier as the basic building unit. The filter circuit realizes quadratic work function. It provides electronically tuning capability of the filter characteristics. The proposed circuit works ideal for Center frequency fo= 10 k and Circuit merit factor Q > 1. The gain roll-off this configuration is 18dB/octave. The circuit is suitable for monolithic integration and high frequency operation. The filters developed were successful in obtaining passive sensitivities less than unity in magnitude and active sensitivities are half in magnitude, which is a noteworthy achievement. The circuit is suitable for high frequency operation and monolithic integration.