An accurate integrated voltage-to-current converter

Presents a monolithic integrated differential voltage-to-current converter. The transconductance of the converter is determined accurately by one external resistor. A total error in the conversion factor as low as /spl plusmn/0.5 percent is obtained by using composite transistors and by using the mutual equality of integrated resistors. The transconductance has a nonlinearity of 0.02 percent and a temperature coefficient of 4/spl times/10/SUP -5///spl deg/C. The output impedance is 5 M/spl Omega/. The voltage-to-current converter is a versatile building block. It can be applied as an instrumentation amplifier, a universal current mirror or current follower, etc.