Design of resistor-less first-order all-pass filter using single VDVTA (Voltage Differencing Voltage Transconducatnce Amplifier)

This paper presents a new realization of a first-order mixed-mode (Voltage input Current output) (MM) all-pass filter (APF) using the recently proposed modern active building block (ABB), namely the Voltage Differencing Voltage Transconductance Amplifier (VDVTA). The MM APF is made using minimum number of components, namely a single VDVTA and one grounded capacitor. The circuit does not use any external resistors and offers the advantages of current-tunable pole frequency, low input impedance and high output impedance. PSPICE simulation results are included to verify the workability of the circuit.