DTMOS based low-voltage low-power all-pass filter

In this paper, a voltage mode all-pass filter design employing floating current sources (FCS) is proposed. The presented all-pass filter circuit contains two floating current sources, one grounded resistor and one floating capacitor. Furthermore, the PMOS transistors of the FCSs are replaced with dynamic threshold-voltage MOSFET (DTMOS) transistors. Due to the use of DTMOS transistors, power consumption and supply voltages of the filter circuit are reduced considerably, compared to the classical circuit. The gain and phase responses, input and output waves, the total harmonic distortion (THD) results, temperature performance, output noise voltage and Monte Carlo (MC) analyses of the all-pass filter are simulated. The simulation results of the proposed DTMOS based circuit are performed with the LTSPICE program using 0.18 μm TSMC CMOS process parameters.