LMH6654MA National Semiconductor, LMH6654MA Datasheet - Page 12

• Manufacturer Part Number: LMH6654MA
• Description: IC, OP-AMP, 260MHZ, 200V/µs, SOIC-8
• Manufacturer: National Semiconductor

Specifications of LMH6654MA

• Op Amp Type: Voltage Feedback
• No. Of Amplifiers: 1
• Bandwidth: 260MHz
• Slew Rate: 200V/µs
• Supply Voltage Range: ± 2.5V To ± 6V
• Amplifier Case Style: SOIC
• No. Of Pins: 8
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Application Information
GENERAL INFORMATION
The LMH6654 single and LMH6655 dual high speed, voltage
feedback
Semiconductor’s new VIP10 (Vertically Integrated PNP) com-
plementary bipolar process. These amplifiers can operate
from ±2.5V to ±6V power supply. They offer low supply cur-
rent, wide bandwidth, very low voltage noise and large output
swing. Many of the typical performance plots found in the
datasheet can be reproduced if 50Ω coax and 50Ω R
resistors are used.
CIRCUIT LAYOUT CONSIDERATION
With all high frequency devices, board layouts with stray ca-
pacitance have a strong influence on the AC performance.
The LMH6654/LMH6655 are not exception and the inverting
input and output pins are particularly sensitive to the coupling
of parasitic capacitance to AC ground. Parasitic capacitances
on the inverting input and output nodes to ground could cause
frequency response peaking and possible circuit oscillation.
Therefore, the power supply, ground traces and ground plan
should be placed away from the inverting input and output
pins. Also, it is very important to keep the parasitic capaci-
tance across the feedback to an absolute minimum.
Open Loop Gain and Phase vs. Frequency
CrossTalk vs. Frequency (LMH6655 only)
amplifiers
are
manufactured
on
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National
20016527
IN
/
ROUT
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The PCB should have a ground plane covering all unused
portion of the component side of the board to provide a low
impedance path. All trace lengths should be minimized to re-
duce series inductance.
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 frequency
filtering on the power supply traces. It is recommended that a
ceramic decoupling capacitor 0.1 µF chip should be placed
with one end connected to the ground plane and the other
side as close as possible to the power pins. An additional 10
µF tantalum electrolytic capacitor should be connected in par-
allel, to supply current for fast large signal changes at the
output.
Isolation Resistance vs. Capacitive Load
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