Datasheet
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Board Layout
Op Amp with Standard SO-14 Pinout—These op amps have the pinout shown in Figure 3. Table 2
shows typical values used for these parts. To select component values for a specific op amp (especially
R
F
x), consult the respective data sheet.
Table 2. Op Amp with Standard SO-14 Pinout
(1)
SINGLE-
DUAL-SUPPLY DUAL-SUPPLY SUPPLY
COMPONENT (G = +2) (G = –1) (G = +1)
R
B
x 49.9Ω 10Ω 49.9Ω
R
B2
x 0Ω 53.6Ω Open
R
S1
x 0Ω Open 0Ω
R
S2
x Open 0Ω Open
R
F
x 800Ω 800Ω 1kΩ
R
G
x 800Ω 800Ω Open
R
OUT
x 49.9Ω 49.9Ω 49.9Ω
C
BYP
V
SP
2.2mF 2.2mF 2.2mF
C
BYP
V
SN
2.2mF 2.2mF Open
C
N
0.1mF 0.1mF 0Ω
C
P
0.1mF 0.1mF 0.1mF
C
PN
0.1mF 0.1mF Open
L
P
0Ω 0Ω 0Ω
L
N
0Ω 0Ω Open
(1)
The values and gains listed here will not work for all op amps. See
the specific data sheet to select proper values. The I/O impedances
are 50Ω.
4 Board Layout
This demonstration fixture is a two-layer PCB. (See Figure 3.) It uses a ground plane on the bottom, and
signal and power traces on the top. The ground plane has been opened up around op amp pins sensitive
to capacitive loading. Power-supply traces are laid out to keep current loop areas to a minimum. The SMA
(or SMB) connectors may be mounted either vertically or horizontally.
The location and type of capacitors used for power-supply bypassing are crucial to high-frequency
amplifiers. The tantalum capacitors, C
BYP
V
SP
and C
BYP
V
SN
, do not need to be as close to pins 11 and 4 on
the PCB, and may be shared with other amplifiers.
See the individual op amp data sheet for more information on proper board layout techniques and
component selection.
5 Measurement Tips
This demonstration fixture, with the component values shown, is designed to operate in a 50Ω
environment; most data sheet plots are obtained under these conditions. It is easy to change the
component values for different input and output impedance levels. However, do not use high-impedance
probes; they represent a heavy capacitive load to the op amp, and will alter the amplifier response.
Instead, use low-impedance (≤ 500Ω) probes with adequate bandwidth. The probe input capacitance and
resistance set an upper limit on the measurement bandwidth. If a high-impedance probe must be used,
place a 100Ω resistor on the probe tip to isolate its capacitance from the circuit.
3
SBOU018B–November 2002–Revised September 2010 DEM-OPA-SO-3B Demonstration Fixture
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