Patent ID: 7012466

Claim:
A voltage-to-current converter including (1) a differential amplifier having non-inverting and inverting input terminals, and (2) associated circuitry for (a) applying an input voltage signal to the converter, and (b) deriving from the associated circuitry an output signal current for driving a load; a sensing resistor series connected with the load and having opposite first and second terminals for respectively applying voltages to first and second feedback loops, the loops being respectively associated with the non-inverting and inverting input terminals of the differential amplifier, each of the loops including (a) an intermediate tap connected to a respective input of the differential amplifier, and (b) a first branch including a first resistor connected between the intermediate tap associated with the particular feedback loop and the terminal of the sensing resistor associated with the particular feedback loop, whereby the sensing resistor is connected between the first branches of the first and second feedback loops, each of the loops also including a second branch having a second resistor connected between the intermediate tap associated with the particular feedback loop and an input port of the converter circuit, the first resistors in the feedback loops have resistance values that are of the same order of magnitude and are substantially higher than the resistance values of the sensing resistor and the load, whereby the current adapted to flow across the sensing resistor is an output current signal directly proportional to the input voltage signal applied between input ports of the second branches of the first and the second feedback loops,said first and second feedback loops include voltage dividers having respective voltage divider ratios defined by said first resistor in said first branch and said second resistor in said second branch, and wherein said respective voltage dividers are the same for said first and second feedback loops.