OPA689 Burr-Brown, OPA689 Datasheet - Page 12

• Manufacturer Part Number: OPA689
• Description: Wideband / High Gain VOLTAGE LIMITING AMPLIFIER
• Manufacturer: Burr-Brown

the OPA689 to have a flat frequency response at a gain of –
2. This increases the loop gain of the op amp feedback
network, which reduces the distortion products below their
specified values.
PRECISION HALF WAVE RECTIFIER
Figure 4 shows a half wave rectifier with outstanding preci-
sion and speed. V
3.8V if left open, while the negative limit is set to ground.
FIGURE 4. Precision Half Wave Rectifier.
VERY HIGH SPEED COMPARATOR
Figure 5 shows a very high speed comparator with hysterisis.
The output level are precisely defined, and the recovery time
is exceptional. The output voltage swings between 0.5V and
3.5V to provide a logic level output that switches as V
crosses V
FIGURE 5. Very High Speed Comparator.
TRANSIMPEDANCE AMPLIFIER
Figure 6 shows a transimpedance amplifier that has excep-
tional overdrive characteristics. The feedback capacitor (C
stabilizes the circuit for the assumed diode capacitance (C
V
IN
V
+V
REF
95.3
IN
100
S
.
= +5V
®
OPA689
H
124
150
3
2
–V
will default to a voltage between 3.1 and
S
OPA689
= –5V
4
2.00k
7
+V
–V
2
3
S
S
8
5
= +5V
OPA689
= –5V
4
7
6
750
NC
1.21k
200k
5
8
604
6
0.1µF
0.1µF
V
O
V
D
O
IN
F
).
)
12
FIGURE 6. Transimpedance Amplifier.
DESIGN-IN TOOLS
APPLICATIONS SUPPORT
The Burr-Brown Applications Department is available
for design assistance at phone number 1-800-548-6132
(US/Canada only). The Burr-Brown Internet web page
(http://www.burr-brown.com) has the latest data sheets and
other design aids.
DEMONSTRATION BOARDS
Two PC boards are available to assist in the initial evaluation
of circuit performance of the OPA689 in both package
styles. These will be available as an unpopulated PCB with
descriptive documentation. See the board literature for more
information. The summary information for these boards is
shown below:
Contact the Burr-Brown Applications Department for avail-
ability of these boards.
SPICE MODELS
Computer simulation of circuit performance using SPICE is
often useful when analyzing analog circuit or system perfor-
mance. This is particularly true for high speed amplifier
circuits where parasitic capacitance and inductance can have
a major effect on frequency response.
SPICE models are available through the Burr-Brown web
site (www.burr-brown.com). These models do a good job of
predicting small-signal AC and transient performance under
a wide variety of operating conditions. They do not do as
well in predicting the harmonic distortion, temperature ef-
fects, or different gain and phase characteristics. These
models do not distinquish between the AC performance of
different package types.
PRODUCT
OPA689P
OPA689U
–V
B
I
D
0.1 F
PACKAGE
8-Pin SO-8
8-Pin DIP
5.0pF
C
D
4.32k
DEM-OPA68xP
DEM-OPA68xU
3
2
NUMBER
BOARD
+V
–V
PART
OPA689
S
S
4.32k
= +5V
= –5V
1.0pF
7
4
C
F
NC
NC
8
5
LITERATURE
6
REQUEST
NUMBER
MKT-350
MKT-351
V
O