AD8224-EVALZ Precision Instrumentation

Precision Instrumentation Amplifier
Evaluation Board
AD8224-EVALZ
FEATURES
GENERAL DESCRIPTION
Two AD8224 circuits
Dual channel
Differential output
Easy to connect screw terminals
Decoupled supply lines
Pads for RFI filtering
The AD8224-EVALZ has two AD8224 instrumentation
amplifier circuits: one circuit is configured for dual-channel
operation, and the other is configured for single-channel,
differential output operation. The inputs, outputs, references,
and supplies are routed to screw terminals for easy connectivity.
The PCB board has four layers. The top and bottom layers are
used for routing, and the two internal layers are ground planes.
The ground plane was removed underneath the RG resistors.
This is a precaution against any capacitance mismatch at the
RGx pins that may affect ac CMRR.
06687-003
AD8224 EVALUATION BOARD
Figure 1.
Rev. 0
Evaluation boards are only intended for device evaluation and not for production purposes.
Evaluation boards as supplied “as is” and without warranties of any kind, express, implied, or
statutory including, but not limited to, any implied warranty of merchantability or fitness for a
particular purpose. No license is granted by implication or otherwise under any patents or other
intellectual property by application or use of evaluation boards. Information furnished by Analog
Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result
from its use. Analog Devices reserves the right to change devices or specifications at any time
without notice. Trademarks and registered trademarks are the property of their respective owners.
Evaluation boards are not authorized to be used in life support devices or systems.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2007 Analog Devices, Inc. All rights reserved.
AD8224-EVALZ
EVALUATION BOARD HARDWARE
SETTING THE GAIN
JUMPER SETTINGS
Table 1.
Jumper
J1A, J1B, J11
J2A, J2B, J12, J13
Purpose
Connect inputs together
Connect reference pins
to ground
Default
Unconnected
Connected
Table 2.
In the default factory setting, the reference pins of the AD8224
are connected to GND through J2A, J2B, J12, and J13. These
jumpers also connect to W2A:REF1, W2B:REF2, W13:REF2, and
W13:+IN2. Therefore, in the shipping configuration, W2A:REF1,
W2B:REF2, W13:REF2, and W13:+IN2 are connected to GND.
To disconnect the terminal from GND, remove the corresponding jumper.
QUICK START
Channel
Dual Channel A
Dual Channel B
Differential Output Channel
Component
R1A
R1B
R11A
EMI FILTERING
The board comes with 0603 component pads for an EMI filter.
These components are shown in Table 3.
Table 3.
The quick start feature assumes that the jumpers are in their
default factory positions.
To begin:
1.
2.
3.
4.
5.
The gain setting resistors are R1A and R1B for the dual-channel
part and R11A for the differential output part. The pads are
sized for 0603-sized resistors, although 0402 and 0805 sizes can
also be used.
Connect a ground lead to GND.
Connect a +15 V supply to +VS.
Connect a −15 V supply to −Vs.
Ground −IN1.
Connect a 1 V p-p, 1 kHz source signal to +IN1. A replica
of the signal should now appear at OUT1.
Channel
Dual Channel A
Dual Channel B
Differential Output Channel
Component
R3A, R2A, C1A, C2A, C3A
R3B, R2B, C1B, C2B, C3B
R13, R12, C11, C12, C13
The board, as shipped, does not contain EMI filtering. The
resistors pads are populated with 0 Ω resistors, and the
capacitors are not populated.
See the AD8224 data sheet for more information on EMI
filtering.
Rev. 0 | Page 2 of 4
AD8224-EVALZ
EVALUATION BOARD SCHEMATICS
REF1 OUT1
OUT2 REF2
W2A
W2B
REF_A
C4
0.1µF +VS
REF_B
J2A
–VS
16
+IN1
14
13
C2A*
1
12
2
11
–IN2
R1A*
R1B*
3
R2A
0Ω
AD8224
W1A
5
+VS
+IN2
R3B
0Ω
9
W1B
DUAL
C3A*
J1B
C2B*
10
4
R2B
0Ω
C3B*
6
7
8
C5
0.1µF
REF_A
06687-001
J1A
15
C1B*
R3A C1A*
0Ω
–IN1
J2B
REF_B
–VS
*NOT POPULATED
Figure 2. AD8224 Evaluation Board Schematic—AD8224 Dual Channel
+OUT –OUT
W12
R10
10kΩ
C14
0.1µF +VS
C10
100pF
–VS
16
–IN1
C12*
J11
+IN1
R12
0Ω
W11
15
14
13
AD8224
R13 C11*
0Ω
DIFF OUT
1
12
2
11
3
10
4
9
R11B*
R11A*
W13
+IN2
C13*
REF2
5
6
7
8
C15
0.1µF
+VS
J13
*NOT POPULATED
–VS
J12
+
+ C8
10µF
+VS
GND1 GND2 GND3 GND4
–VS
W6
W5
+VS
06687-002
C7
10µF
–VS
Figure 3. AD8224 Evaluation Board Schematic—AD8224 Differential Output
Rev. 0 | Page 3 of 4
AD8224-EVALZ
ORDERING INFORMATION
ORDERING GUIDE
Model
AD8224-EVALZ1
1
ESD CAUTION
Description
Evaluation Board
Z = RoHS Compliant Part.
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
EB06687-0-3/07(0)
Rev. 0 | Page 4 of 4