Mostafa Parvizi - Department of Electrical Engineering, Najafabad Branch, Islamic Azad
Hamed Tasdighi - department of electrical and computer engineering .

This paper presents a multi-functional (Universal) second-order GM-C filter. The filter designed will carry out all filter responses, including high- pass, low-pass, band- pass, band- stop and all- pass. Both capacitors used in this structure are grounded, which is contributory to the simplification of chips construction, in addition to the reduction of disturbances and interference agents. The OTA circuit implemented in this filter is a NOT- gate circuit which reduces the number of transistors in the circuit, resulting in lower power consumption, lower noise, lower chip area, etc. Decrease in the number of the transistors, will also cause decreased interfering capacitors, and allow the circuit to operate at higher frequencies. The filter is structured so as to perform all of the filter frequency response functions simultaneously, with only one input voltage. Low sensitivity, is the other advantages of this filter. Results of simulation by HSPICE software and CMOS 0.18 μm technology show that, with ±0.4 V power supply and capacitors C1 = C2 = 1 pF , the filter has a center frequency of F0 = 4MHZ , and power consumption of 5.2 μw.

GM-C Filter Universal, Simultaneously, Voltage Mode