Built this precision voltage and current reference the other day to calibrate some multimeters of mine. It features a ADR01B reference,
which has an initial accuracy of 0.05% and a temperature drift of 1 to 4 ppm/degC.
Construction is fairly simple: 10V is output directly on two pins and buffered by an opamp, the opamp output is fed through a precision potentiometer, whose center tap is the 0..10V output and also fed into another opamp which generates the variable current source based on the adjustable voltage. The ADR01 is short circuit proof, so I didn’t bother to buffer its output further. There is a linear power supply for a ~12Vdc supply, a DC/DC converter to generate ±15V for some operational amplifiers. That’s the general overview.
