L DESIGN FEATURES How to Choose a Voltage Reference
by Brendan Whelan Why Voltage References? 5V It is an analog world. All electronic
devices must in some way interact with
the “real” world, whether they are in
an automobile, microwave oven or cell
phone. To do that, electronics must be
able to map real world measurements
(speed, pressure, length, temperature)
to a measurable quantity in the electronics world (voltage). Of course, to
measure voltage, you need a standard
to measure against. That standard is
a voltage reference. The question for
any system designer is not whether he
needs a voltage reference, but rather,
which one?
A voltage reference is simply that—a
circuit or circuit element that provides
a known potential for as long as the circuit requires it. This may be minutes,
hours or years. If a product requires
information about the world, such VIN 18k LTC1286
1
2 LT1634-4.096 0.1ВµF 3
4 VREF VCC +IN CLK –IN DOUT GND CS/SHDN 8 5V 7 …