Evaluation Board User Guide
One Technology Way
•
P.O. Box 9106
•
Norwood, MA 02062-9106, U.S.A.
•
Tel: 781.329.4700
•
Fax: 781.461.3113
•
www.analog.com
UG-422
AD8476
Differential Amplifier Evaluation Board for
8-Lead MSOP Package
FEATURES
Enables quick evaluation of
AD8476
Enables quick breadboarding/prototyping
Allows for various circuit configurations
Through-hole connector provisions
Easy connection to test equipment and other circuits
RoHS compliant
The 4-layer evaluation board accepts through-hole SMA or
SMB connectors on inputs, outputs, and VOCM, which allows
an efficient and quick connection to test equipment or other
circuitry. There is also room for 2-pin BERG headers at the
inputs and outputs for connection to differential probes, and
test points at supply and ground pins. The board ground plane,
component placement, and power supply bypassing have been
optimized for maximum circuit flexibility and performance.
Figure 1 and Figure 2 show the component side and circuit side
of the evaluation board. Figure 3 shows the evaluation board
schematic.
Figure 4 shows the evaluation board assembly drawing.
The metal layout pattern for connecting the board to the op
amp and to the supporting circuitry is shown in Figure 5 and
Figure 6.
The board accommodates the
AD8476
differential amplifier
in an 8-lead MSOP. The
AD8476
data sheet for this device
should be consulted in conjunction with this evaluation board
user guide.
GENERAL DESCRIPTION
The
AD8476-EVALZ
makes it easy for designers to obtain quick
performance results for their particular application circuit using
the
AD8476
low power, fully-differential G = 1 amplifier.
The board layout is flexible enough to allow for different circuit
configurations, including options for single-ended or differ-
ential inputs, and space for output loading and filtering. Most
resistors and capacitors use 0603 packages.
10778-001
Figure 1. Component Side (MSOP)
Figure 2. Circuit Side (MSOP)
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.
Rev. 0 | Page 1 of 8
10778-002
UG-422
TABLE OF CONTENTS
Features .............................................................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
AD8476 Evaluation Board Schematic ............................................ 3
Evaluation Board Hardware ............................................................ 4
Power Supplies .............................................................................. 4
Evaluation Board User Guide
VOCM Input ..................................................................................4
SMB Input/Output Connectors ...................................................4
Evaluation Board Layout ..................................................................5
Ordering Information .......................................................................6
Bill of Materials ..............................................................................6
Related Links ......................................................................................6
REVISION HISTORY
5/12—Revision 0: Initial Version
Rev. 0 | Page 2 of 8
Evaluation Board User Guide
AD8476
EVALUATION BOARD SCHEMATIC
−VS
C4
10µF
+
UG-422
C2
0.1µF
INP
8
IN+
R1*
7
−Vs
6
NC
5
−OUT
10kΩ
J1
R3*
JP1
10kΩ
+
AD8476
–
10kΩ
10kΩ
R5*
R7*
R9*
R6*
JP2
OUT−
J4
OUT+
IN−
R2*
R8*
J2
R4*
J5
1
2
3
4
INN
+Vs
VOCM
+OUT
VOCM
VOCM
C1
0.1µF
C5*
0.1µF
+
*User defined value
10778-003
R10*
J3
C3
10µF
+VS
Figure 3.
AD8476
Evaluation Board Schematic
Rev. 0 | Page 3 of 8
UG-422
EVALUATION BOARD HARDWARE
POWER SUPPLIES
Power is applied to the board through test pins +V
S
and −V
S
(see Figure 3). The board accommodates single or dual supplies.
For single-supply operation, connect the negative supply to the
ground plane.
It is very important that the power supply pins of the device
under test (DUT) have a broadband decoupling circuitry. The
board layout facilitates this with footprints for a 0603 ceramic
capacitor (C1 and C2) on each supply. Bulk decoupling is
provided by C3 and C4; 10 µF tantalum capacitors are
recommended.
Evaluation Board User Guide
VOCM INPUT
To set the output common-mode voltage of the
AD8476,
an
external voltage can be applied to VOCM via J3 (referenced
to the ground plane of the board) or the VOCM test point. In
ADC driving applications, it is convenient to apply the ADC
dc reference voltage output directly to J3. A 0.1 μF capacitor
(C5) is used in normal applications to provide bypassing for
the dc voltage applied to the VOCM pin.
VOCM can also be left unconnected. The
AD8476
internally
sets the output common-mode to mid-supply.
SMB INPUT/OUTPUT CONNECTORS
The inputs and outputs have through-hole SMB connector
footprints (which are compatible with most SMA connector
footprints) for convenient connection to coaxial cables. The
recommended connector type is Johnson Components™,
Part Number 131-0701-371 (jack) and 131-1801-371 (plug),
or equivalent.
Rev. 0 | Page 4 of 8
Evaluation Board User Guide
EVALUATION BOARD LAYOUT
UG-422
Figure 4. Assembly Drawing Component Side
10778-004
10778-005
Figure 5. Component Side Metallization (MSOP)
Figure 6. Circuit Side Metallization (MSOP)
Rev. 0 | Page 5 of 8
10778-006
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