AD581
THE PRECISION 12-BIT D/A CONVERTER REFERENCE
AD562, like most D/A converters, is designed to operate with a
+10 volt reference element. In the AD562, this 10 volt reference
voltage is converted into a reference current of approximately
0.5 mA via the internal 19.95 kΩ resistor (in series with the ex-
ternal 100
Ω
trimmer). The gain temperature coefficient of the
AD562 is primarily governed by the temperature tracking of the
19.95 kΩ resistor and the 5k/10k span resistors; gain TC is
guaranteed to 3 ppm/°C. Thus, using the AD581L (at 5 ppm/°C)
as the 10 volt reference guarantees a maximum full-scale tem-
perature coefficient of 8 ppm/°C over commercial range. The 10
volt reference also supplies the normal 1 mA bipolar offset cur-
rent through the 9.95k bipolar offset resistor. The bipolar offset
TC thus depends only on TC matching of the bipolar offset
resistor to the input reference resistor and is guaranteed to
3 ppm/°C.
Figure 14. AD581 as Negative 10-Volt Reference for
CMOS ADC
Figure 15. Precision 12-Bit D/A Converter
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
–6–
REV. B
PRINTED IN U.S.A.
C418d–0–3/00 (rev. B)
AD [ ANALOG DEVICES ]
