Evaluate: MAX2654/MAX2655/MAX2656
MAX2654/MAX2655/MAX2656 Evaluation Kits
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Quick Start
The MAX2654/MAX2655/MAX2656 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 -30dBm
of output power and a frequency range covering
the MAX2654/MAX2655/MAX2656 (1400MHz to
2000MHz, for example)
• 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 a desired frequency 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 6mA for MAX2654, 8mA for
MAX2655, and 11mA for MAX2656.
5) Activate the RF generator’s output. A signal on the
spectrum analyzer’s display should indicate a typical
gain as shown on the device data sheet after
accounting for cable and board losses.
6) Optional: For the MAX2656, set the jumper JU2 to the
V
CC
position. The power gain should now be about
1dB.
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 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 docu-
ment. Take into account PC board and external compo-
nents loss when performing noise-figure measure-
ments. The typical input losses on these EV kits is
0.2dB at 1575MHz and 0.25dB at 1960MHz. For more
information on how to perform this level of noise-figure
measurement, 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
circuit’s design. The EV kit PC board can serve as a
guide for laying out a board using the MAX2654/
MAX2655/MAX2656. 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 essen-
tial. Connect the GND pins to the ground plane either
directly, through vias, or both. For MAX2654, connect
pin 1 to the PC board ground plane through a 0.017in
width by 0.035in length line.
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