Evaluate: MAX2642/MAX2643
MAX2642/MAX2643 Evaluation Kits
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Quick Start
The MAX2642/MAX2643 EV kits are fully assembled and
factory tested. Follow the instructions in the Connections
and Setup section for proper device evaluation.
Test Equipment Required
• An RF signal generator capable of delivering -10dBm
of output power and a frequency range covering the
MAX2642/MAX2643 (800MHz to 1000MHz, for exam-
ple)
• An RF spectrum analyzer that covers the operating
frequency range
• A DC power supply capable of supplying +2.7V to
+5.5V
• Two 50Ω coaxial cables with SMA connectors
• An ammeter to measure supply current (optional)
• A noise figure meter (optional)
• A network analyzer for measuring gain and return
loss (optional)
Connections and Setup
Checking Power Gain
1) Connect a DC supply (preset to +3.0V) to the V
CC
and GND terminals (through an ammeter, if desired)
on the EV kit.
2) Set the RF generator for an output frequency of
900MHz at a power level of -30dBm. Connect the RF
generator’s output to the RFIN SMA connector.
3) Connect the coaxial cable from the RFOUT SMA con-
nector to the spectrum analyzer.
4) Turn on the DC supply. The supply current should
read approximately 5mA (if using an ammeter).
5) Activate the RF generator’s output. A signal on the
spectrum analyzer’s display should indicate a typical
gain of +17dB after accounting for cable and board
losses.
6) Optional: For the MAX2642, set the jumper JU2 to the
V
CC
position. The power gain should now be
+3.5dB.
7) Optional: Another method of determining gain is by
using a network analyzer. This has the advantage of
displaying gain vs. a swept frequency band, in addi-
tion to displaying input and output return loss. Refer
to the user manual of the network analyzer for setup
details.
Checking Noise Figure
Noise figure measurements on low-noise devices such
as the MAX2642/MAX2643 are extremely sensitive to
board and lab setup losses and parasitics. There are
many techniques and precautions for measuring low
noise figure. A detailed explanation of these items
would exceed the scope of this document. Take into
account PC board and external components loss when
performing noise-figure measurements. The typical
input losses on these EV kits is 0.25dB. For more infor-
mation on how to perform this level of noise-figure mea-
surement, refer to the noise-figure meter operating
manual and to Hewlett Packard’s application note #57-2,
Noise Figure Measurement Accuracy.
Layout Considerations
Good PC board layout is an essential part of an RF cir-
cuit’s design. The EV kit PC board can serve as a guide
for laying out a board using the MAX2642/MAX2643.
Generally, the V
CC
node on the PC board should have
a decoupling capacitor located close to the device,
and additional capacitors may be needed for long V
CC
lines. This minimizes supply coupling. Proper grounding
of the GND pins is essential. Connect the GND pins to
the ground plane either directly, through vias, or both.
