參數(shù)資料
型號(hào): OPA644
英文描述: OPA644 - DISCONTINUED PRODUCT. No longer recommended for new design.
中文描述: OPA644 -已停產(chǎn)產(chǎn)品。不再推薦用于新設(shè)計(jì)。
文件頁(yè)數(shù): 3/4頁(yè)
文件大小: 59K
代理商: OPA644
3
DEM-OPA68xU
OPA681U
—Pin 8 disables the output when low. Table VIII
shows different ways to set up pin 8’s voltage using R
8
, R
9
and C
7
. Use Table III for the other components.
OPA682U
—The OPA682U uses internal resistors to set the
gain at +1, +2, or –1. Pin 8 disables the output when low.
Table VIII shows different ways to set up pin 8’s voltage
using R
8
, R
9
and C
7
. Use Table III for the other components,
except for the changes shown in Table IX.
OPA689U
—This VLA is the high gain-stable version of
the OPA688U. Set up this op amp the same as the OPA688U,
except for the changes shown in Table XII.
DUAL SUPPLY
(G = +2)
DUAL SUPPLY
(G = –1)
SINGLE SUPPLY
(G = +1)
COMPONENT
R
4
R
5
R
6
Open
0
Open
0
Open
Open
Open
Open
Open
TABLE IX. OPA682U Changes.
OPA686U
—Use Table X for the higher gains needed by
this part, and Table IV for the other component values. Extra
care is needed to ensure pin 8 is not connected (see Table I).
DUAL SUPPLY
(G = +10)
DUAL SUPPLY
(G = –10)
SINGLE SUPPLY
(G = +20)
COMPONENT
R
1
R
2
R
3
R
4
R
5
R
6
49.9
20.0
Open
Open
49.9
453
Open
Open
10.0
49.9
Open
499
49.9
10.0
Open
Open
26.1
499
TABLE X. OPA686U Changes.
OPA688U
—This VLA (Voltage Limiting Amplifier) has
two inputs (V
H
and V
L
in Table I), which limit the output
voltage swing. Table XI shows different ways to set up pin
5’s and pin 8’s voltages using R
8
- R
13
and C
5
- C
7
. Use
Table IV for the other components.
Note that this board would require modification for the
single-supply circuit shown in the OPA688 data sheet. In
dual supply applications, using R
10
instead of R
8
makes V
H
negative, and using R
13
instead of R
11
makes V
L
positive.
DUAL SUPPLY
(G = +2)
DUAL SUPPLY
(G = –1)
SINGLE SUPPLY
(G = +1)
COMPONENT
R
8
R
9
R
11
R
12
R
3.01k
1.91k
3.01k
1.91k
Open
0.1
μ
F
3.01k
1.91k
3.01k
1.91k
Open
0.1
μ
F
549
1.58k
Open
549
1.58k
0.1
μ
F
C
5
- C
7
TABLE XI. Limiting Pins—OPA68xU.
DUAL SUPPLY
(G = +6)
DUAL SUPPLY
(G = –6)
SINGLE SUPPLY
(G = +6)
COMPONENT
R
1
R
2
R
3
R
4
R
5
R
6
49.9
100
Open
Open
150
750
82.5
Open
130
124
Open
750
49.9
100
Open
Open
150
750
TABLE XII. OPA689U Changes.
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.
The location and type of capacitors used for power-supply
bypassing are crucial to high frequency amplifiers. The
tantalum capacitors, C
1
and C
2
, do not need to be as close to
pins 7 and 4 on your 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 selec-
tion.
MEASUREMENT TIPS
This demonstration board and the component values shown
are designed to operate in a 50
environment. Most data
sheet plots are obtained this way. Change the component
values for different input and output impedance levels.
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 (
500
) 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 100
resistor on the
probe tip to isolate its capacitance from the circuit.
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
OPA644U 制造商:Rochester Electronics LLC 功能描述:- Bulk
OPA644UB 制造商:BB 制造商全稱:BB 功能描述:Low Distortion Current Feedback OPERATIONAL AMPLIFIER
OPA646 制造商:BB 制造商全稱:BB 功能描述:Low Power, Wide Bandwidth OPERATIONAL AMPLIFIER
OPA646 WAF 制造商:Texas Instruments 功能描述:
OPA646U 制造商:Rochester Electronics LLC 功能描述:- Bulk