Abstract
In recent years, the current mode active component is popular in scholastic discussion and commercial purposes. Current mode active components have the advantages of wider bandwidths, larger dynamic range, lower power consumption, smaller area and easier to design. The current-mode circuit is proved to be much more precise than its voltage-mode counter part. Since the transconductance of an operational transconductance amplifier (OTA) is electronically adjusted by the internal bias current, no resistors in the OTA-C circuit become an important advantage in the active filter design. In the thesis, the new OTA structure is presented and it is used in biquad filter. In this thesis, we proposed transconductance element with low power fully differential transconductor based on long tail differential pair (LTP) with adaptively biased technique, which generate suitable compensating current witch extend the input-output linear range. The result of Hspice simulation shows that with ±1.1V power supply, linearity range is between -0.7V and 0.7V. The proposed transconductor is used to design second order biquad filter. The transconductance of a transconductor is electronically adjusted by the internal bias current, so that suitable corner frequency and quality factor is obtained.