Datasheet

REV. B
–7–
AD2S99
AD2S99/AD2S93 TYPICAL CONFIGURATION
Figure 5 shows a typical circuit configuration for the AD2S99
Oscillator and the AD2S93 LVDT-to-Digital Converter. The
maximum level of the A and B transducer input signals to the
AD2S93 should be 1 V rms ± 20%. All the analog ground sig-
nals should be star connected to the AD2S93 AGND pin. If
shielded twisted pair cables are used for the LVDT signals, the
shields should also be terminated at the AD2S93 AGND pin.
The SYNREF output of the AD2S99 cannot be used as the
REF input signal for the AD2S93. The zero crossing reference
for the AD2S93 should be taken from the primary winding of
the LVDT through a phase lead or lag network. The phase com-
pensation network ensures that the REF input is phase coherent
with the A and B input signals to the AD2S93.
NC = NO CONNECT
NC
SIN
NC
DGND
COS
EXC
EXC
NC
AGND
NC
193 12 20
4
5
8
6
7
12 1391110
18
17
14
16
15
TOP VIEW
(Not to Scale)
AD2S99
FBIAS
SEL1
V
SS
SEL2
V
SS
NC
SYNREF
NC
LOS
V
DD
4.7µF
4.7µF
0.1µF
0.1µF
SEC
PRI
LVDT
V
DD
V
SS
V
DD
0.1µF
50kΩ
4.7µF
0.1µF 4.7µF
V
SS
SEL2 = GND
SEL1 = V
SS
F
OUT
= 5kHz
V
DD
NC = NO CONNECT
DATA
SCLK
UNR
CLKOUT
NC
NC
26
27
28
4
2
3
15
18
17
16
12
14
13
25 24 21 20 1923 22
1
56 9101178
CS
R2
C2
C1
C3
R5
R6
R7
C4
DMODOUT
B
A
PHASE
COMP
LOS
TOP VIEW
(Not to Scale)
AD2S93
B
NC
LOS
GAIN
DIFF
AGND
A
V
SS
DGND
DIR
NULL
OVR
REF
NC
VEL
DMODIN
ACERROR
VGAIN
INTIN
V
DD
Figure 5. AD2S99 and AD2S93 Example Configuration