MGA-72543-TR1 Avago Technologies US Inc., MGA-72543-TR1 Datasheet - Page 19

• Manufacturer Part Number: MGA-72543-TR1
• Description: IC,Microwave/Millimeter Wave Amplifier,GAAS,SOT-343R,PLASTIC
• Manufacturer: Avago Technologies US Inc.

Specifications of MGA-72543-TR1

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Even though a design may be unconditionally stable (K >
1 and B1 > 0) over its full frequency range, other possibili-
ties exist that may cause an amplifier circuit to oscillate.
One condition to check for is feedback in the bias circuit.
It is important to capacitively bypass the connections to
active bias circuits to ensure stable operation. In multi-
stage circuits, feedback through bias lines can also lead
to oscillation.
Components of insufficient quality for the frequency
range of the amplifier can sometimes lead to instabil-
ity. Also, component values that are chosen to be much
higher in value than is appropriate for the application can
present a problem. In both of these cases, the compo-
nents may have reactive parasitics that make their imped-
ances very different than expected. Chip capacitors may
have excessive inductance, or chip inductors can exhibit
resonances at unexpected frequencies.
• A Note on Supply Line Bypassing
Multiple bypass capacitors are normally used throughout
the power distribution within a wireless system. Consider-
ation should be given to potential resonances formed by
the combination of these capacitors and the inductance
of the DC distribution lines. The addition of a small value
resistor in the bias supply line between bypass capacitors
will often de-Q the bias circuit and eliminate resonance
effects.
Statistical Parameters
Several categories of parameters appear within the
electrical specification portion of the MGA-72543 data
sheet. Parameters may be described with values that
are either “minimum or maximum, ” “typical, ” or “standard
deviations. ”
The values for parameters are based on comprehensive
product characterization data, in which automated
measurements are made on a statistically significant
number of parts taken from nonconsecutive process lots
of semiconductor wafers. The data derived from product
characterization tends to be normally distributed, e.g., fits
the standard bell curve.
Parameters considered to be the most important to
system performance are bounded by minimum or
maximum values. For the MGA-72543, these parameters
are: V
anteed parameters is 100% tested as part of the normal
manufacturing and test process.
Values for most of the parameters in the table of Electrical
Specifications that are described by typical data are the
mathematical mean (µ ), of the normal distribution taken
from the characterization data. For parameters where
19
c test
, NF
test
, G
a test
, IIP
3 test
, and IL
test
. Each of the guar-
Figure 15. Normal Distribution Curve.
Phase Reference Planes
The positions of the reference planes used to specify S-
parameters and Noise Parameters for the MGA-72543 are
shown in Figure 16. As seen in the illustration, the refer-
ence planes are located at the point where the package
leads contact the test circuit.
Figure 16. Phase Reference Planes.
measurements or mathematical averaging may not be
practical, such as S-parameters or Noise Parameters and
the performance curves, the data represents a nominal
part taken from the center of the characterization distri-
bution. Typical values are intended to be used as a basis
for electrical design.
To assist designers in optimizing not only the immediate
amplifier circuit using the MGA-72543, but to also evalu-
ate and optimize trade-offs that affect a complete wireless
system, the standard deviation (σ) is provided for many
of the Electrical Specification parameters (at 25°C). The
standard deviation is a measure of the variability about
the mean. It will be recalled that a normal distribution is
completely described by the mean and standard devia-
tion.
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 15 for example, the probability of a parameter
being between ±1σ is 68.3%; between ±2σ is 95.4%; and
between ±3σ is 99.7%.
-3σ
TEST CIRCUIT
REFERENCE
-2σ
PLANES
-1σ
Parameter Value
68%
95%
99%
Mean (µ)
(typical)
+1σ +2σ +3σ