A 0.5/spl mu/A precision CMOS floating-gate analog reference

A precision voltage reference with a TC <1ppm//spl deg/C is implemented using a floating-gate technique in a 1.5/spl mu/m CMOS process. The reference is factory programmed from 0.5 to 5V without trim circuits to 0.2mV accuracy. The chip shows long-term drift of 10ppm/(1khr)/sup 0 2/.