max2650eust Maxim Integrated Products, Inc., max2650eust Datasheet - Page 5

• Manufacturer Part Number: max2650eust
• Description: Max2650 Dc-to-microwave, +5v Low-noise Amplifier
• Manufacturer: Maxim Integrated Products, Inc.

The MAX2650 is a broadband amplifier with flat gain
and 50Ω input and output ports. Its small size and inter-
nal bias circuitry make it ideal for applications where
board space is limited.
As shown in the Typical Operating Circuit, the
MAX2650 is easy to use. Input and output series
capacitors may be necessary to block DC bias volt-
ages (generated by the MAX2650) from interacting with
adjacent circuitry. These capacitors must be large
enough to contribute negligible reactance in a 50Ω sys-
tem at the minimum operating frequency. Use the fol-
lowing equation to calculate their minimum value:
where f (in MHz) is the minimum operating frequency.
The V
tion. To accomplish this, connect a capacitor between
the V
practical. Use the same equation given above (for DC
blocking capacitor values) to calculate the minimum
capacitor value. If there are long V
board, additional bypassing may be necessary. This
may be done further away from the package, at your
discretion.
Proper grounding of the GND pin is essential. If the PC
board uses a topside RF ground, the GND pin should
connect directly to it. For a board where the ground
plane is not on the component side, the best technique
is to connect the GND pin to it through multiple plated
through-holes.
_______________Detailed Description
__________Applications Information
CC
CC
pin and ground, as close to the package as is
pin must be RF bypassed for correct opera-
DC-to-Microwave, +5V Low-Noise Amplifier
C
BLOCK
_______________________________________________________________________________________
=
53,000
External Components
f
CC
(pF)
lines on the PC
An example PC board layout is given in Figure 1. It
uses FR-4 with 31mil layer thickness between the RF
lines and the ground plane. The board satisfies all the
above requirements.
Figure 1. Example PC Board Layout
EXPANDED VIEW
RF IN
V
PC Board Layout Example
CC
MAX2650
RF OUT
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