LMH6609MA National Semiconductor, LMH6609MA Datasheet - Page 11

• Manufacturer Part Number: LMH6609MA
• Description: Operational Amplifier (Op-Amp) IC
• Manufacturer: National Semiconductor

Specifications of LMH6609MA

• No. Of Amplifiers: 1
• Slew Rate: 1400V/µs
• No. Of Pins: 8
• Peak Reflow Compatible (260 C): No
• Input Bias Current: 8000µA
• Supply Voltage Max: 12V
• Leaded Process Compatible: No
• No. Of Channels: 1
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Application Section
GAIN BANDWIDTH PRODUCT
The LMH6609 is a voltage feedback amplifier, whose
closed-loop bandwidth is approximately equal to the gain-
bandwidth product (GBP) divided by the gain (A
greater than 5, A
LMH6609.
For Gains less than 5, refer to the frequency response plots
to determine maximum bandwidth. For large signal band-
width the slew rate is a more accurate predictor of band-
width.
Where f
amplitude.
OUTPUT DRIVE AND SETTLING TIME PERFORMANCE
The LMH6609 has large output current capability. The
100mA of output current makes the LMH6609 an excellent
choice for applications such as:
When driving a capacitive load or coaxial cable, include a
series resistance R
• Video Line Drivers
• Distribution Amplifiers
MAX
FIGURE 4. AC Coupled Non-Inverting
= bandwidth, S
V
OUT
sets the closed-loop bandwidth of the
to back match or improve settling
R
= Slew rate and V
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V
). For gains
P
= peak
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time. Refer to the Driving Capacitive Loads section for guid-
ance on selecting an output resistor for driving capacitive
loads.
EVALUATION BOARDS
National Semiconductor provides the following evaluation
boards as a guide for high frequency layout and as an aid in
device testing and characterization. Many of the datasheet
plots were measured with these boards.
A free evaluation board is automatically shipped when a
sample request is placed with National Semiconductor.
CIRCUIT LAYOUT CONSIDERATION
A proper printed circuit layout is essential for achieving high
frequency performance. National provides evaluation boards
for the LMH6609 as shown above. These boards were laid
out for optimum, high-speed performance. The ground plane
was removed near the input and output pins to reduce
parasitic capacitance. Also, all trace lengths were minimized
to reduce series inductances.
Supply bypassing is required for the amplifiers performance.
The bypass capacitors provide a low impedance return cur-
rent path at the supply pins. They also provide high fre-
quency filtering on the power supply traces. 10µF tantalum
and .01µF capacitors are recommended on both supplies
(from supply to ground). In addition a .1µF ceramic capacitor
can be added from V
suppression.
DRIVING CAPACITIVE LOADS
Capacitive output loading applications will benefit from the
use of a series output resistor R
of a series output resistor, R
driving an analog to digital converter. The charts "Suggested
R
recommended value for mitigating capacitive loads. The val-
ues suggested in the charts are selected for .5dB or less of
peaking in the frequency response. This gives a good com-
promise between settling time and bandwidth. For applica-
tions where maximum frequency response is needed and
some peaking is tolerable, the value of R
slightly from the recommended values. There will be ampli-
tude lost in the series resistor unless the gain is adjusted to
compensate; this effect is most noticeable with heavy resis-
tive loads.
LMH6609MA
LMH6609MF
O
FIGURE 5. Driving Capacitive Loads with R
vs. Cap Load" in the Typical Performance Section give a
Device
SOIC
SOT-23
Improved Stability
+
Package
to V
OUT
−
OUT
to aid in second harmonic
as it might be applied when
. Figure 5 shows the use
CLC730227
CLC730216
Board Part #
O
can be reduced
www.national.com
OUT
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for