Voltage-mode all-pass filter design using simple CMOS transconductor: Non-ideal case study

In this paper, basic transconductor composed of only p-channel and n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) and its utilization for low-voltage first-order voltage-mode (VM) all-pass filter (APF) design is studied. For initial filter design a general structure employing single transconductor and two admittances was proposed. By choosing passive components and considering real behavior of MOSFETs, i.e. parasitic capacitances and output resistances, six specific cases for VM APF design are discussed. SPICE simulations using IBM 0.13 μm level-7 SIGE013 CMOS process BSIM3v3.1 parameters and with ±0.75 V supply voltages are included to support the theoretical results. The selected solution was designed at pole frequency of 219 MHz and consumes 480 μW power.