A novel current-mode and Voltage-mode all pass filter employing operational transconductance amplifier

This paper proposes a novel first order all pass filter that utilizes operational transconductance amplifier as an active device. The introduced filter circuit comprises of only two active device and one grounded capacitor and four resistors. It also provides the voltage-mode and current-mode output simultaneously without doing any alteration in its hardware configuration. The transfer function of the filter circuit in both the modes remains same. In Current-mode the output current is explicitly available from high impedance port, makes it better proposition for making the higher order filters without using any additional buffers. CMOS OTAs using 0.18 µm technology process parameters have been utilized to test and verify the filter circuit.