AN-0991: Active Filter Evaluation Board for Standard SOIC Op Amps (Rev. A)

AN-0991
APPLICATION NOTE
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Active Filter Evaluation Board for Standard SOIC Op Amps
by John Ardizzoni
board has provisions for edge-mounted SMA connectors, which
simplify testing and integration.
The EVAL-FLTR-SO-1RZ active filter evaluation board is
designed to work with standard pinout op amps. The filter
board enables quick prototyping of two-, four-, or six-pole lowor high-pass Sallen-Key active filters. The board schematic
shown in Figure 1 is for a low-pass filter. Converting the board
from a low-pass filter to a high-pass filter is accomplished by
swapping the location of the filter resistors and capacitors. The
C1
R1
C5
R5
VIN
R10
C12
C7 10µF
+VS
RT
The active filter evaluation board is bare, which enables the user
to customize the filter design. The filter board assembly
drawing is shown in Figure 2. All components are 0603 case
sizes with the exception of the large bypass capacitors, which
are 3216 case sizes.
C3
0.1µF
+
VS+
R2
R7
V+
VS+
C8 0.1µF
R12
V+
C13
0.1µF
V+
U1
U2
V– C4
0.1µF
GND
V–
C9 0.1µF
C6
–VS
+
R3
–VS
AGND
R6
VOUT1
R9
R8
R14
R11
R13
VOUT2
Figure 1. Active Filter Evaluation Board Schematic
SECONDARY SIDE
PRIMARY SIDE
07953-002
R4
C14
V– 0.1µF
C11
C10 10µF
GND
–VS
U3
07953-001
C2
R15
VOUT3
AGND
Figure 2. Active Filter Evaluation Board Assembly Drawing
Rev. A | Page 1 of 2
AN-0991
Application Note
NOTES
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registered trademarks are the property of their respective owners.
AN07953-0-8/10(A)
Rev. A | Page 2 of 2