MGA-81563 Ver la hoja de datos (PDF) - Avago Technologies
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MGA-81563 Datasheet PDF : 11 Pages
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Standard statistics tables or calculations provide the prob-
ability of a parameter falling between any two values,
usually symmetrically located about the mean. Referring
to Figure 12 for example, the probability of a parameter
being between ±1V is 68.3%; between ±2V is 95.4%; and
between ±3V is 99.7%.
68%
95%
99%
-3σ -2σ -1σ Mean (μ) +1σ +2σ +3σ
(typical)
Parameter Value
Figure 12. Normal Distribution.
RF Layout
The RF layout in Figure 13 is suggested as a starting point
for microstripline designs using the MGA-81563 amplifier.
Adequate grounding is needed to obtain optimum per-
formance and to maintain stability. All of the ground pins
of the MMIC should be connected to the RF groundplane
on the backside of the PCB by means of plated through
holes (vias) that are placed near the package terminals.
As a minimum, one via should be located next to each
ground pin to ensure good RF grounding. It is a good
practice to use multiple vias to further minimize ground
path inductance.
line on FR-4, for example, has approximately 0.3 dB loss at
4 GHz. This loss will add directly to the noise figure of the
MGA-81563.
Biasing
The MGA-81563 is a voltage-biased device and is designed
to operate from a single, +3 volt power supply with a typi-
cal current drain of 42 mA. The internal current regulation
circuit allows the amplifier to be operated with voltages
as high +5 volts or as low as +1.5 volt. Refer to the section
titled “Operation at Bias Voltages Other than 3 Volts” for
information on performance and precautions when using
other voltages.
Typical Application Example
The printed circuit layout in Figure 14 can serve as a de-
sign guide. This layout is a microstripline design (solid
groundplane on the backside of the circuit board) with a
50Ω input and output. The circuit is fabricated on 0.031-
inch thick FR-4 dielectric material. Plated through holes
(vias) are used to bring the ground to the top side of the
circuit where needed. Multiple vias are used to reduce the
inductance of the paths to ground.
OUT
IN
+V
50 Ω
RF Input
RF Output
and Vd
50 Ω
Figure 13. RF Layout.
It is recommended that the PCB pads for the ground pins
not be connected together underneath the body of the
package. PCB traces hidden under the package cannot be
adequately inspected for SMT solder quality.
PCB Material
FR-4 or G-10 printed circuit board materials are a good
choice for most low cost wireless applications. Typical
board thickness is 0.020 to 0.031 inches. The width of the
50: microstriplines on PC boards in this thickness range is
also very convenient for mounting chip components such
as the series inductor at the input or DC blocking and by-
pass capacitors.
For higher frequencies or for noise figure critical applica-
tions, the additional cost of PTFE/glass dielectric materials
may be warranted to minimize transmission line loss at
the amplifier’s input. A 0.5 inch length of 50Ω microstrip-
MGA-8-A
Figure 14. PCB Layout.
A schematic diagram of the application circuit is shown
in Figure 15. DC blocking capacitors (C1 and C2) are used
at the input and output of the MMIC to isolate the device
from adjacent circuits. Although the input terminal of the
MGA-81563 is at ground potential, it is not a current sink.
If the input is connected to a preceding stage that has a
voltage present, the use of the DC blocking capacitor (C1)
is required.
RF
Input C1 L1
C2
Vd
C4
RFC
C2
RF
Output
Figure 15. Schematic Diagram.
DC bias is applied to the MGA-81563 through the
RF Output pin. An inductor (RFC), or length of high
impedance transmission line (preferably O/4 at the band
center), is used to isolate the RF from the DC supply.
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