OPA2652E BURR-BROWN [Burr-Brown Corporation], OPA2652E Datasheet - Page 11

• Manufacturer Part Number: OPA2652E
• Description: Dual, 700MHz, Voltage-Feedback OPERATIONAL AMPLIFIER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

R
magnitude. The rise and fall times of the input pulses (t
should be slow enough to prevent pre-shoot artifacts in the
response.
SIMPLE BANDPASS FILTER
Figure 7 shows the OPA2652 used as simple bandpass filter.
The OPA2652 is well suited for this type of circuit because
it is very stable at a noise gain of +1.
FIGURE 7. Inverting Bandpass Filter.
DESIGN-IN TOOLS
DEMONSTRATION BOARDS
PC boards are available to assist in the initial evaluation of
circuit performance using the OPA2652. They are available
free as unpopulated PC boards delivered with descriptive
documentation. The summary information for these boards is
shown below:
Contact the Burr-Brown Applications support line to request
this board.
FIGURE 6. Pulse Delay Circuit.
PRODUCT
OPA2652U
OPA2652E
F
and R
G
V
IN
need to be equal to maintain a constant gain
t
r (IN)
8-Lead SO-8
C
PACKAGE
1
SOT23-8
402
5RC, minimal pre-shoot
402
V
–5V
DEM-OPA2652E
+5V
DEM-OPA26xU
OPA2652
IN
1/2
402
NUMBER
BOARD
C
PART
2
C
402
R
R
G
V
OUT
ORDERING
NUMBER
MKT-352
MKT-365
–5V
+5V
OPA2652
1/2
402
R
r(IN)
F
)
11
MACROMODELS AND APPLICATIONS SUPPORT
Computer simulation of circuit performance using SPICE is
often useful when analyzing the performance of analog
circuits and systems. This is particularly true for Video and
RF amplifier circuits where parasitic capacitance and induc-
tance can have a major effect on circuit performance. Check
the Burr-Brown web site (www.burr-brown.com) for avail-
able SPICE products (not all parts have models). 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 har-
monic distortion or dG/d characteristics. These models do
not attempt to distinguish between the package types in their
small-signal AC performance.
OPERATING SUGGESTIONS
OPTIMIZING RESISTOR VALUES
Since the OPA2652 is a unity gain stable voltage feedback
op amp, a wide range of resistor values may be used for the
feedback and gain setting resistors. The primary limits on
these values are set by dynamic range (noise and distortion)
and parasitic capacitance considerations. For a non-inverting
unity gain follower application, the feedback connection
should be made with a 25 resistor, not a direct short. This
will isolate the inverting input capacitance from the output
pin and improve the frequency response flatness. Usually,
the feedback resistor value should be between 200
1.5k . Below 200 , the feedback network will present
additional output loading which can degrade the harmonic
distortion performance of the OPA2652. Above 1.5k , the
typical parasitic capacitance (approximately 0.2pF) across
the feedback resistor may cause unintentional band-limiting
in the amplifier response.
A good rule of thumb is to target the parallel combination of
R
The combined impedance R
ing input capacitance, placing an additional pole in the
feedback network, and thus a zero in the forward response.
Assuming a 2pF total parasitic on the inverting node, hold-
ing R
itself, this constraint implies that the feedback resistor R
can increase to several k at high gains. This is acceptable
as long as the pole formed by R
tance appearing in parallel is kept out of the frequency range
of interest.
C
402
F
and R
R
F
|| R
G
G
(Figure 1) to be less than approximately 300 .
< 300 will keep this pole above 250MHz. By
–5V
+5V
OPA2652
1/2
402
V
F
O
|| R
OPA2652
F
G
and any parasitic capaci-
interacts with the invert-
and
F
®