Upgraded low voltage analog Current-to-Voltage converter with negative feedback

In this paper, an improved version of a current to voltage (C-V) converter is proposed. As compared to the previous version, the number of used transistors has been reduced by 1 and equals 7. The main results of this change are: an improvement of the circuit transfer function linearity, reduction the converter input resistance and decrease of the required supply voltage. Improvements in the considered converter results not only from the reduction of the number of the used transistors but also from the proposed realization of the feedback loop. In this way, it was possibly to get a strong loop gain. As a results, the achieved minimum supply voltage has been reduces from 2V, in case of the previous published converter version, to as low level as 1.2 V, in the case of the newly proposed solution. As for the linearity of the C-V transfer function, apart from its strong loop gain, an important role play also output transistors operating in a small drain to source region (linear region). Working in this region, one obtains a quasi linear voltage to current relationship. The theoretical and simulation results are in a good agreement and are promising.