
The XFET® voltage reference
Characteristics of Monolithic Voltage References
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14.3 The XFET
®
voltage reference
When Analog Devices unveiled its revolutionary XFET
®
in 1997, it was a major mile-
stone in the evolution of the monolithic voltage reference. It had been about two
decades since a completely new voltage reference topology had last been intro-
duced. In fact, Analog Devices at that time had introduced the series bandgap, in the
form of the AD580. The existing topologies available in the mid-90s were shunt and
series bandgaps and variations of the buried-zener. Because Analog Devices already
made bandgaps, buried-zeners, ADCs, and DACs, it ...