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AD2S44
Data Sheet
Rev. B | Page 10 of 12
Ka does not define maximum acceleration; it defines only the
error due to acceleration. The maximum acceleration of which
the AD2S44 keeps track is approximate to 5 × Ka = 310,000°/sec2 or about 800 revolutions/sec2.
Ka can be used to predict the output position error due to input
acceleration. For example, an acceleration of 50 revolutions/sec2
with Ka = 62,000 is calculated using the following equation:
[
]
=
=
2
sec
a
K
LSB
on
Accelerati
Input
LSBs
in
Errors
[
]
LSBs
rev
LSB
rev
2
.
13
sec
000
,
62
2
sec
50
2
14
2
=
×
RELIABILITY
The reliability of these products is very high due to the extensive
use of custom chip circuits that decrease the active component
count. Calculations of the MTBF figure under various environ-
mental conditions are available upon request from Analog
Devices.
Figure 9 shows the MTBF in years vs. case temperature for
Naval Sheltered conditions calculated in accordance with the
Mil-Hdbk-217E.
TEMPERATURE (°C)
M
TB
F
(
Y
ears)
100
10
1
25
65
45
85
105
125
02947-
009
Figure 9. MTBF vs. Temperature
PROCESSING FOR HIGH RELIABILITY (B SUFFIX)
As a part of the high reliability manufacturing procedure, all
converters receive the processing shown in
Table 6.Table 6.
Conditions
Precap Visual Inspection
MIL-STD-883, Method 2017
Temperature Cycling
10 cycles, –65°C to +150°C
Constant Acceleration
5000 Gs, Y1 plane
Interim Electrical Tests
@ 25°C
Operating Burn In
160 hours @ 125°C
Seal Test, Fine and Gross
MIL-STD-883, Method 1014
Final Electrical Test
Performed at TMIN, TAMB, TMAX
External Visual Inspection
MIL-STD-883, Method 2009
1
Test and screening data supplied by request.
OTHER PRODUCTS
Analog Devices manufactures many other products concerned
with the conversion of synchro/resolver data, such as the
SDC/RDC1740 series and the AD2S80A series.
Hybrid
The SDC/RDC1740 is a hybrid synchro/resolver-to-digital
converter with internal isolating micro transformers.
Monolithic
The AD2S80A series are ICs performing resolver-to-digital
conversion with accuracies up to ±2 arc minutes and 16-bit
resolution.