CMOS class-AB tunable voltage-feedback current operational amplifier

We describe a CMOS class AB Voltage Feedback Current Operational Amplifier (VFCOA) offering both tunable gain (from 0 dB to 24 dB) and bandwidth (from 1 MHz to 3MHz). The implementation is based on class AB second generation current conveyors and exploits an electronically tunable transistorized feedback network. The solution was fabricated in 0.5-μm technology, the die area was 0.127 mm² and measurement results show a dynamic range (1%, 300kHz, maximum gain) of 87.5 dB and a THD lower than −40dB for an output current 23 times the bias current.