A CMOS current-voltage feedback transconductor with an 80-dB SFDR up to 100 MHz

This paper proposes a transconductor using current-voltage feedback to achieve high linearity. We construct a feedforward voltage-to-current amplifier by using a simple fully differential OTA and form feedback network by using a pair of resistors which perform current sampling and voltage mixing at the inputs. The circuit is realized in TSMC 0.18-μm 1P6M CMOS process with a 1.8 V supply voltage. The transconductor achieves an 80-dB spurious free dynamic range (SFDR) for a 2 V differential input swing up to 100 MHz and a 60-dB SFDR even up to 1 GHz. The DC power consumption of the transconductor core is 2.58 mW.