ad2s46 Analog Devices, Inc., ad2s46 Datasheet - Page 7

• Manufacturer Part Number: ad2s46
• Description: Low Cost, L6-bitsynchro Resolver -to-digital Converte
• Manufacturer: Analog Devices, Inc.

ANALOGDEVICES fAX-ON-DEHAND HOTLINE
REV. 0
ence in series with RLo and RHI'
DYNAMIC PERFORMANCE
The transfer function of the convener is given below.
Open-loop transfer function
Qosed-loop transfer function
where KA =: 48000 see-l
The gain and phase diagrams are shown in Figures 3 and 4.
To calculate the values of the external scaling resistors add
S4 (resolver options only), and 3 kn in extra per volt of refer-
1.111 kfi extra per volt of signal in series with SI, 82, S3 and
f
A.
W
!fi
9
....
9
A. 0
~
i!:
-180
-135
T 1 = 0.0071 see
T2 =: 0.00125 see
-90
-45
180
135
-2
-3
-4
90
45
-1
18.75
0
4
3
2
18.75
eOUT -
GIN - I + sTI
Figure 3. AD2S48 Gain Plot
Figure 4. AD2S46 Phase Plot
37.5
37.5
-=:
GOUT
alN
FREQUENCY
FREQUENCY
KA (1 + sTJi
S (1 + sT2)
+ sllKA + 1'3T2/KA
2
75
I + sTI
75
-
Page
150
150
18
300
300
-7-
RELIABILITY
The reliability of these products is very high due to the exten-
sive use of custom chip circuits that decrease the active compo-
nent count. Calculations of the MTBF fIgUre under various
environmental conditions are available on request.
Figure 5 shows the MTBF in years vs. case temperature for
Naval Sheltered conditions and airborne uninhabited cargo
calculated in accordance with MIL-HDBK-217E.
revolutionslsec2 with K = 48000,
degrees. Alternatively, the angular unit of measure may be in
radians, minutes of arc, LSBs, etc.
acceleration. The maximum acceleration for which the AD2S46
will not lose track is in the order of S° x KA
or about 660 revolutions/sec2.
KA can be used to predict the output position error due to input
acceleration. For example. for an acceleration of 50
ACCELERATION ERROR
A tracking converter employing a Type 2 servo loop does not
suffer any velocity lag, however, there is an additional error due
to acceleration. This additional error can be defined using the
acceleration constant KA of the converter.
The numerator and denominator must have consistent angular
units. For example. if KA is in sec-l, then tbe input acceleration
may be specified in degrees/see and the error in output angle in
KA does not define maximum acceleration, only the error due to
fIj
a:
ooC
w
>
1000
100
10
Figure 5. AD2S48 MTBF V5. Temperature
0
Error in LSBs
25
K""=
50 [rev/reel] x 216[LSB/seel]
45
:::::::......
=
E
TEMPERATURE
rror In
Input Acceleration [LSB/seel]
= 68 LSBs
AUC"""""""""" """
Input Aceekratwn
""' :-0...
47662 [sec-l]
65
.
Ou
NS
KA
tpUl ng e
85
:::::::"""
-
[see-2]
Al
DC
=
105
238,000 0/sec2
AD2S46
125