Implementation of current-to-voltage converter with wide dynamic range and its application

A current-to-voltage converter (CVC) with wide dynamic range and good linearity is presented, which consists of a trans-impedance amplifier (TIA), an adjusting current generator, and two ADCs. Main algorithm of the CVC is two-step conversion. First, a rough location of an input current is traced using one ADC, a coarse-ADC with N-bit resolution, and the input current shifts to the linear region of the TIA by current subtraction. Next, the other ADC converters the TIA output which corresponds to the shifted current. This converter is implemented using a 0.35 ¿m CMOS technology. Measurement results indicate that a maximum linear input current is enlarged by 2N times.