Highly-linear rail-to-rail 1.2 V-0.18μm CMOS V-I converter

Presented is a new high-performance CMOS V-I converter based on an OTA/common source amplifier configuration. To achieve rail-to-rail operation, the voltage across the linear V-I conversion resistor is reduced by means of local feedback, thereby keeping the output mirroring transistor in saturation over the entire input voltage range. Experimental results for a 1.2 V-0.18 μm CMOS design confirm rail-to-rail operation with transconductance gain errors below 2.2% over a -40 to + 120 °C range, THD below -52 dB for a 100 kHz-1 V_pp input signal and bandwidth above 14 MHz with 70 μW power consumption and 100 × 112 m² active area.