A 3Volt high frequency and low input impedance CMOS current-mode precision full-wave rectifier

This paper presents a 3VoIt high frequency and low input impedance CMOS current mode precision full-wave rectifier. The circuit is designed based on an improved Wilson current miller. All MOS transistors are biased at low current resulting in small power dissipation. Negative feedback has been employed to reduce the input impedance of the circuit(236 /spl Omega/). HSPICE is used to perform the simulation and the result shows the frequency of operation as high as 100 MHz with a standard 0.5 /spl mu/m CMOS technology. The mismatch obtained from the input and rectifier's output is 0.21% for an input current of /spl plusmn/150 /spl mu/A. The DC transfer characteristic shows good linearity, very sharp corner at zero crossing point and good symmetry during positive and negative input cycle while power dissipation is 5.8 /spl mu/W.