Precision Instrumentation Amplifier
Evaluation Board
AD8222-EVALZ
Rev. 0
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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. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
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Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved.
FEATURES
Two AD8222 circuits
Dual channel
Differential out
Easy to connect screw terminals
Decoupled supply lines
Pads for RFI filtering
GENERAL DESCRIPTION
The AD8222-EVALZ has two AD8222 instrumentation
amplifier circuits: one circuit is configured for dual-channel
operation, while the other is configured for single-channel,
differential output operation. Inputs, outputs, references, and
the 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
two RG pins, which may affect ac CMRR.
JUMPER SETTINGS
Table 1.
Jumpers Purpose Default
J1A, J1B, J11 Connect inputs together Unconnected
J2A, J2B, J12, J13 Connect reference pins to
ground
Connected
In the default factory setting, the reference pins of the AD8222
are connected to GND through J2A, J2B, J12, and J13.
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
The quick start feature assumes that the jumpers are in their
factory default positions.
To begin:
Connect ground lead to GND.
Connect a 15 V supply to +VS.
Connect a −15 V supply to −Vs.
Ground −IN1.
Connect a 1V p-p, 1 kHz source signal to +IN1. A replica of
the signal should now appear at OUT1.
0
6386-001
Figure 1. AD8222-EVALZ Evaluation Board Photo
SETTING THE GAIN
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.
EMI FILTERING
The board comes with 0603 component pads for an EMI filter.
These components are shown in Table 2.
Table 2.
Channel Components
Dual Channel A R3A, R2A, C1A, C2A, C3A
Dual Channel B R3B, R2B, C1B, C2B, C3B
Differential Output Channel 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 AD8222 data sheet for more information on EMI
filtering.
AD8222-EVALZ
Rev. 0 | Page 2 of 2
06386-002
GND1 GND2 GND3 GND4
+V –V
+V –V
W5W6
C8
10µF
C7
10µF
4
5
1
16 14 13
12
9
15
2
3
–V
678
–IN
+IN 10
11
C15
0.1µF
W11
R10
10k
C10
100pF
R11
SPARE
R13
0
R12
0
J11
C11
SPARE
C12
SPARE
C13
SPARE
R11A
SPARE
AD8222
DIFF OUT
W12
–OUT+OUT
W13
+IN2
REF2
J13
–V
+V
J12
+V
C14
0.1µF
4
5
1
16 14 13
12
9
15
2
3
–V
678
–IN1
+IN1
10
11
W1A
R2B
0
R3B
0
R1B
SPARE
W1B
C3A
SPARE
C2A
SPARE
J1A
C1A
SPARE
R1A
SPARE
AD8222
DUAL
R3A
0
R2A
0
REF_A
+V REF_B
C5
0.1µF
C3B
SPARE
C2B
SPARE
C1B
SPARE
J1B
–IN2
+IN2
J2A J2B
REF_A
REF_B
W2BW2A
REF1 OUT1 REF2OUT2
C4
0.1µF +V
–V
Figure 2. AD8222-EVALZ Evaluation Board Schematic
ESD CAUTION
ORDERING GUIDE
Model Description
AD8222-EVALZ1Evaluation Board
1 Z = Pb-free part.
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
EB06386-0-11/06(0)