MGA-87563-TR2G Ver la hoja de datos (PDF) - Avago Technologies
Número de pieza
componentes Descripción
Fabricante
MGA-87563-TR2G Datasheet PDF : 9 Pages
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Output Matching
The output of the MGA-87563 is matched internally to 50
Ω above 1.8 GHz. The use of a conjugate matching circuit,
such as a simple series inductor, can increase the gain
considerably at lower frequencies. Matching the output
will not affect the noise figure.
Stability
If the MGA-87563 is cascaded with highly reactive stages
(such as filters) some precautions may be needed to en-
sure stability. The low frequency stability (under 1.5 GHz)
of the MGA-87563 can be enhanced by adding a series
R-L network in shunt with the output, as shown in Figure
12. The inductor can be either a chip component or a
high impedance transmission line as shown in the figure.
Component values are selected such that the output of the
MGA-87563 will be resistively loaded at low frequencies
while allowing high frequency signals to pass the stability
load with minimal loss.
MGA
87563
DC BLOCKING
CAPACITOR
25-50 Ω
RF
OUTPUT
HIGH IMPEDANCE
TRANSMISSION
OR INDUCTOR
Figure 12. Output Circuitry for Low Frequency Stability.
Typical values for the resistor are in the 25 to 50Ω range.
A suggested starting place for the inductor is a 0.35 to
0.40-inch long microstripline with a width of 0.020 inches,
using 0.031-inch thick FR-4 (r = 4.8) circuit board as the
substrate.
For applications near 1.5 GHz, gain (and output power)
may be traded off for increased stability.
Some precautions regarding the Vdd connection of the
MGA-87563 are also recommended to ensure stability
within the operating frequency range of the device. It is
important that the connection to the power supply be
properly bypassed to realize full amplifier performance.
Refer to the Biasing section above for more information.
SOT-363 PCB Layout
A PCB pad layout for the miniature SOT-363 (SC-70) pack-
age is shown in Figure 13 (dimensions are in inches). This
layout provides ample allowance for package placement by
automated assembly equipment without adding parasitics
that could impair the high frequency RF performance of
the MGA-87563. The layout is shown with a nominal SOT-
363 package footprint superimposed on the PCB pads.
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Figure 13. Recommended PCB Pad Layout for Avago’s SC70 6L/SOT-363
Products.
RF Layout
The RF layout in Figure 14 is suggested as a starting point
for designs using the MGA-87563 amplifier. Adequate
grounding is needed to obtain maximum performance
and to obviate potential instability. All three ground pins
of the MMIC should be connected to RF ground by using
plated through holes (vias) near the package terminals.
RF OUTPUT
VDD
50 Ω
87
50 Ω
Figure 14. RF Layout.
RF INPUT
6
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