DEM-OPA368XU [ETC]
DEM-OPA368xU - Evaluation Fixture ; DEM - OPA368xU - 评价灯具\n型号: | DEM-OPA368XU |
厂家: | ETC |
描述: | DEM-OPA368xU - Evaluation Fixture
|
文件: | 总3页 (文件大小:59K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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DEM-OPA368xU
EVALUATION FIXTURE
COMPONENTS
DESCRIPTION
Components that have RF performance similar to the
ones in Table I may be substituted.
The DEM-OPA368xU demonstration board is an
unpopulated printed circuit board (PCB) for the high
speed triple op amps with disable available in SO-16
packages. The DEM-OPA368xU supports Burr-
Brown’s OPA3680U, OPA3681U, and OPA3682U.
Figure 1 shows the package pinout for this PCB. For
more information on these op amps, and good PCB
layout techniques, see the individual op amp data sheets.
R1 and R7 set the I/O impedance, R2 - R6 set the gain,
R8 and C8 set up the disable pin, and C1 - C7 are supply
bypass capacitors. C3 is optional; it adds a bypass
between the supplied, which improves distortion per-
formance for some models. L1 - L2 are ferrite chips
that can reduce interactions with the power supply at
high frequencies; if not desired, they can be replaced
with 0Ω resistors.
The ordering number for this board is MKT-364. Limit
of 5 per customer.
For single supply operation, do not connect L2; other-
wise, the –VS input to P1 would be at ground potential.
CIRCUIT
The circuit schematic in Figure 2 shows the connec-
tions for all possible components. Each model will
only use some of the components.
J3A
Top View
SO-16
DIS A
–IN A
+IN A
DIS B
–IN B
+IN B
DIS C
–IN C
+IN C
1
2
3
4
5
6
7
8
16 DIS A
15 +VS
R8A
C8A
16
R3A
R2A
R4A
R5A
2
1
J1A
J2A
R7A
14
IN A
Out A
14 OUT A
13 –VS
9, 13
R1A
C6
R6A
P1
C4
L2
L1
12 OUT B
11 +VS
–VS
GND
+VS
C2
C1
+
+
C3
C5
J3B
10 OUT C
DIS B
C7
R8B
C8B
9
–VS
R3B
R2B
R4B
R5B
11,
15
5
4
3
R7B
R6B
J1B
J2B
12
IN B
Out B
DIS C
FIGURE 1. Pin Configuration.
R1B
PART
C1, C2
DESCRIPTION
J3C
Tantalum Chip Capacitor, SMD EIA size 3528, 20V
Multi-Layer Ceramic Chip Cap., SMD 1206, 50V
SMA or SMB Board Jack (Amphenol 901-144-8)
R8C
C3 - C8C
J1A - J3C
L1, L2
C8C
R3C
R2C
R4C
R5C
8
7
6
J1C
J2C
R7C
R6C
EMI-Suppression Ferrite Chip, SMD 1206
(Steward LI 1206 B 900 R)
10
IN C
Out C
R1C
P1
Terminal Block, 3.5mm centers
(On-Shore Technology ED555/3DS)
R1A - R8C
Metal Film Chip Resistor, SMD 1206, 1/8W
FIGURE 2. Circuit Schematic for DEM-OP368xU.
TABLE I. Part Descriptions.
International Airport Industrial Park
•
Mailing Address: PO Box 11400, Tucson, AZ 85734
•
Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706
• Tel: (520) 746-1111
Twx: 910-952-1111 Internet: http://www.burr-brown.com/
•
•
Cable: BBRCORP Telex: 066-6491
•
•
FAX: (520) 889-1510 Immediate Product Info: (800) 548-6132
•
© 1999 Burr-Brown Corporation
LI-546
Printed in U.S.A. December, 1999
Disable Pins—Pins 16, 3 and 6 disable op amps A, B and
C when low. Table II shows different ways to set up these
pins’ voltages.
BOARD LAYOUT
This demonstration board is a two-layer PCB. 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.
CONFIGURATION
R8
C6
External Source
49.9Ω
Open
0Ω
Open
0.1µF
Open
On
Off
The location and type of capacitors used for power-supply
bypassing are crucial to high frequency amplifiers. The
tantalum capacitors, C1 and C2, do not need to be as close to
the supply pins on your PCB and may be shared with other
amplifiers.
TABLE II. Disable Pin—OPA368xU.
OPA3680U—Table III shows typical values for this part.
For more information, consult the data sheet.
See the individual op amp data sheet for more information
on proper board layout techniques, and component selec-
tion.
DUAL SUPPLY
(G = +2)
DUAL SUPPLY SINGLE SUPPLY
COMPONENT
(G = –1)
(G = +1)
R1
R2
R3
R4
R5
R6
R7
C1, C2
C3
C4 - C7
49.9Ω
178Ω
Open
Open
402Ω
402Ω
49.9Ω
2.2µF
0.01µF
0.1µF
57.6Ω
Open
210Ω
402Ω
Open
402Ω
49.9Ω
2.2µF
0.01µF
0.1µF
49.9Ω
0Ω
Open
Open
Open
24.9Ω
49.9Ω
2.2µF
Open
0.1µF
MEASUREMENT TIPS
This demonstration board, and the component values shown,
are designed to operate in a 50Ω environment. Most data
sheet plots are obtained this way. It is easy to change the
component values for different input and output impedance
levels.
NOTE: The I/O impedances are 50Ω.
Do not use high impedance probes; they represent a heavy
capacitive load to the op amps, and will alter their 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.
TABLE III. OPA3680U.
OPA3681U—Table IV shows typical values for this part.
For more information, consult the data sheet.
DUAL SUPPLY
(G = +2)
DUAL SUPPLY SINGLE SUPPLY
COMPONENT
(G = –1)
(G = +1)
R1
R2
R3
R4
R5
R6
R7
C1, C2
C3
C4 - C7
49.9Ω
10.0Ω
Open
Open
402Ω
402Ω
49.9Ω
2.2µF
0.01µF
0.1µF
57.6Ω
Open
10.0Ω
402Ω
Open
402Ω
49.9Ω
2.2µF
0.01µF
0.1µF
49.9Ω
10.0Ω
Open
Open
Open
402Ω
49.9Ω
2.2µF
Open
0.1µF
NOTE: The I/O impedances are 50Ω.
TABLE IV. OPA3681U.
OPA3682U—The OPA3682U uses internal resistors to set
the gain at +1, +2, or –1. Use Table IV for the components,
except for the changes in Table V.
DUAL SUPPLY
(G = +2)
DUAL SUPPLY SINGLE SUPPLY
COMPONENT
(G = –1)
(G = +1)
R4
R5
R6
Open
0Ω
Open
0Ω
Open
Open
Open
Open
Open
NOTE: The I/O impedances are 50Ω.
TABLE V. OPA3682U Changes.
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DEM-OPA368xU
(a)
(b)
FIGURE 3. DEM-OPA368xU Demonstration Board Layout; (a) Component Side Silkscreen and Metal, (b) Ground Plane Side
Silkscreen and Metal (bottom view).
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DEM-OPA368xU
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