Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

AD698 Datasheet(PDF) 6 Page - Analog Devices

Part No. AD698
Description  Universal LVDT Signal Conditioner
Download  12 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  AD [Analog Devices]
Homepage  http://www.analog.com
Logo 

AD698 Datasheet(HTML) 6 Page - Analog Devices

Zoom Inzoom in Zoom Outzoom out
 6 / 12 page
background image
REV. B
–6–
AD698
CONNECTING THE AD698
The AD698 can easily be connected for dual or single supply
operation as shown in Figures 7, 8 and 13. The following gen-
eral design procedures demonstrate how external component
values are selected and can be used for any LVDT that meets
AD698 input/output criteria. The connections for the A and B
channels and the A channel comparators will depend on which
transducer is used. In general follow the guidelines below.
Parameters set with external passive components include: exci-
tation frequency and amplitude, AD698 input signal frequency,
and the scale factor (V/inch). Additionally, there are optional
features; offset null adjustment, filtering, and signal integration,
which can be implemented by adding external components.
R1
C1
15nF
C2
C3
R4
R3
13
16
15
14
24
23
22
21
20
19
18
17
12
11
10
9
8
1
2
3
4
7
6
5
AD698
–VS
EXC1
EXC2
LEV1
LEV2
FREQ1
BFILT1
BFILT2
–BIN
+BIN
–AIN
FREQ2
SIG REF
OFFSET2
OFFSET1
+VS
OUT FILT
FEEDBACK
SIG OUT
–ACOMP
AFILT2
AFILT1
+ACOMP
+AIN
C4
R2
33k
1000pF
SIGNAL
REFERENCE
RL
VOUT
100nF
6.8µF
–15V
+15V
100nF
6.8µF
Figure 7. Interconnection Diagram for Half-Bridge LVDT
and Dual Supply Operation
DESIGN PROCEDURE
DUAL SUPPLY OPERATION
Figure 7 shows the connection method for half-bridge LVDTs.
Figure 8 demonstrates the connections for 3- and 4-wire
LVDTs connected in the series opposed configuration. Both ex-
amples use dual
±15 volt power supplies.
A. Determine the Oscillator Frequency
Frequency is often determined by the required BW of the sys-
tem. However, in some systems the frequency is set to match
the LVDT zero phase frequency as recommended by the
manufacturer; in this case skip to Step 4.
1. Determine the mechanical bandwidth required for LVDT
position measurement subsystem, fSUBSYSTEM. For this ex-
ample, assume fSUBSYSTEM = 250 Hz.
2. Select minimum LVDT excitation frequency approximately
10
× f
SUBSYSTEM. Therefore, let excitation frequency = 2.5 kHz.
3. Select a suitable LVDT that will operate with an excitation
frequency of 2.5 kHz. The Schaevitz E100, for instance, will
operate over a range of 50 Hz to 10 kHz and is an eligible
candidate for this example.
4. Select excitation frequency determining component C1.
C1
= 35 µFHz/f
EXCITATION
R1
C1
C2
C3
R4
R3
13
16
15
14
24
23
22
21
20
19
18
17
12
11
10
9
8
1
2
3
4
7
6
5
AD698
–VS
EXC1
EXC2
LEV1
LEV2
FREQ1
BFILT1
BFILT2
–BIN
+BIN
–AIN
FREQ2
SIG REF
OFFSET2
OFFSET1
+VS
OUT FILT
FEEDBACK
SIG OUT
–ACOMP
AFILT2
AFILT1
+ACOMP
+AIN
C4
R2
1000pF
SIGNAL
REFERENCE
RL
VOUT
100nF
6.8µF
–15V
+15V
100nF
6.8µF
1M
AB
C
D
PHASE
LAG/LEAD
NETWORK
RT
AB
CD
PHASE LEAD
RS
C
C
RS
RS
RT
A
B
CD
PHASE LAG
C
PHASE LAG = Arc Tan (Hz RC);
PHASE LEAD = Arc Tan 1/(Hz RC)
WHERE R = RS// (RS + RT)
Figure 8. AD698 Interconnection Diagram for Series
Opposed LVDT and Dual Supply Operation
B. Determine the Oscillator Amplitude
Amplitude is set such that the primary signal is in the 1.0 V to
3.5 V rms range and the secondary signal is in the 0.25 V to
3.5 V rms range when the LVDT is at its mechanical full-scale
position. This optimizes linearity and minimizes noise suscepti-
bility. Since the part is ratiometric, the exact value of the excita-
tion is relatively unimportant.
5. Determine optimum LVDT excitation voltage, VEXC. For a
4-wire LVDT determine the voltage transformation ratio,
VTR, of the LVDT at its mechanical full scale. VTR =
LVDT sensitivity
× Maximum Stroke Length from null.
LVDT sensitivity is listed in the LVDT manufacturer’s cata-
log and has units of volts output per volts input per inch dis-
placement. The E100 has a sensitivity of 2.4 mV/V/mil. In
the event that LVDT sensitivity is not given by the manufac-
turer, it can be computed. See section on determining LVDT
sensitivity.


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12 


Datasheet Download



Related Electronics Part Number

Part NumberComponents DescriptionHtml ViewManufacturer
NE5521LVDT signal conditioner 1 2 3 4 5 NXP Semiconductors
AD598LVDT Signal Conditioner 1 2 3 4 5 MoreAnalog Devices
LTM-STR44-Channel Webcasting Video and Audio Signal Conditioner 1 List of Unclassifed Manufacturers
ZMD31015Low-cost sensro signal conditioner with dignostics 1 2 Zentrum Mikroelektronik Dresden AG
ZMD31020Sensor Signal Conditioner 1 2 3 4 5 MoreZentrum Mikroelektronik Dresden AG
ZMD31030Automotive Sensor Signal Conditioner with LIN Interface 1 2 Zentrum Mikroelektronik Dresden AG
1B31Wide Bandwidth Strain Gage Signal Conditioner 1 2 3 4 5 MoreAnalog Devices
ZMD31035Automotive Sensor Signal Conditioner 1 2 Zentrum Mikroelektronik Dresden AG
1B32Bridge Transducer Signal Conditioner 1 2 3 4 5 MoreAnalog Devices
PA1001ASIGNAL CONDITIONER & CONVERTERS 1 2 3 4 5 MoreList of Unclassifed Manufacturers

Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn