Current-to-voltage converter with controllable gain, and signal processing circuit comprising such a converter

Abstract

Summarizing, the present invention provides an IVC (100), comprising an operational amplifier (110) with an inverting input (112) and an output (113), and a feedback resistor ladder network (120) coupled between the output (113) and the inverting input (112). The feedback resistor ladder network (120) comprises a main chain (121) composed of a plurality of substantially identical unit resistors (RU) connected in series, and a plurality of branches (124i), each branch (124i) coupling a node (Xi) in the main chain (121) to the inverting input (112) of the operational amplifier (110), each branch (124i) comprising a selectable feedback switch (123i). Further, some of the branches (124i) comprise a non-unit resistor (RNUi) coupled in series with the corresponding selectable feedback switch (123i). Further, the present invention provides a circuit comprising a FIRDAC (20) and a bias block (30) for providing at least one bias current for the FIRDAC (20). The bias block (30) comprises at least one bias resistor (RB). The FIRDAC (20) is associated with at least one IVC (25, 26), configured as described above, wherein the unit resistors (RU) of the at least one IVC (25, 26) are substantially identical to the bias resistor (RB) of the bias block (30).

Dependencies are inferred from the claim text.