Datasheet

Data Sheet AD5686R/AD5685R/AD5684R
Rev. B | Page 27 of 32
THERMAL HYSTERESIS
Thermal hysteresis is the voltage difference induced on the
reference voltage by sweeping the temperature from ambient
to cold, to hot, and then back to ambient.
Thermal hysteresis data is shown in Figure 59. It is measured
by sweeping the temperature from ambient to −40°C, then
to +105°C, and returning to ambient. The V
REF
delta is then
measured between the two ambient measurements and
shown in blue in Figure 59. The same temperature sweep
and measurements were immediately repeated and the
results are shown in red in Figure 59.
Figure 59. Thermal Hysteresis
Table 15. 24-Bit Input Shift Register Contents for Internal Reference Setup Command
1
DB23
(MSB)
DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 to DB1 DB0 (LSB)
0 1 1 1 X X X X X 1/0
Command bits (C3 to C0) Address bits (A2 to A0) Don’t care Reference setup register
1
X = don’t care.
9
8
7
6
5
4
3
2
1
0
500–50–100–150–200
HITS
DISTORTION (ppm)
10485-062
FIRST TEMPERATURE SWEEP
SUBSEQUENT TEMPERATURE SWEEPS