TITLE:
Realization of a New Current Mode Second-Order Biquad Using Two Current Follower Transconductance Amplifiers (CFTAs)
AUTHORS:
Nisha Walde, Syed Naseem Ahmad
KEYWORDS:
Current Follower Transconductance Amplifier (CFTA), Current-Mode Circuit, Biquad Filter, Voltage-Mode Circuit, Current Conveyor (CC)
JOURNAL NAME:
Circuits and Systems,
Vol.6 No.5,
May
18,
2015
ABSTRACT: A new circuit for realization of universal
current-mode filter using current Follower Transconductance Amplifiers (CFTAs)
is presented. The proposed circuit realizes current-mode low pass, high pass
and band pass filter functions simultaneously with a single current source at
the input. The band reject and all pass filters can also be obtained from the
proposed circuit without any extra hardware. The proposed circuit employs three
passive grounded elements and two CFTAs. Linear electronic control of natural
frequency ω0 is available in the proposed circuit. The quality factor can be
independently adjusted through grounded resistor. The proposed circuit employs
two grounded capacitors and a grounded resistor along with two CFTAs. The
grounded resistor can be replaced by an OTA based circuit for linear electronic
control of quality factor Q0. The circuit exhibits low active and passive
sensitivities for ω0 and Q0. Simulation results are obtained using PSPICE
software which is in conformity with the theoretical findings.