Evaluates: MAX2112
7) Turn on the 3.3V V
CC
power supply, followed by
the 3V gain-control power supply. The supply cur-
rent from the 3.3V V
CC
supply should read approx-
imately 100mA, and the supply current from the 3V
V
GC
should read approximately 50µA. Be sure to
adjust the power supply to account for any voltage
drop across the ammeter.
8) Install and run the IC control software. Software is
available for download on the Maxim website at
www.maxim-ic.com/evkitsoftware.
9) Load the default register settings from the control
software by clicking Edit: Load Defaults. Set
ICP = 1 and BBG[3:0] = 1011.
10) Connect the output to a spectrum analyzer or an
oscilloscope.
11) Enable the RF signal generator’s output.
12) Activate and set the power level of the RF genera-
tor to achieve 1V
P-P
at the baseband BNC connec-
tor outputs.
13) Check the I/Q outputs.
14) Observe the baseband output at 5MHz with 1V
P-P
.
Layout Considerations
The EV kit can serve as a guide for PCB layout. Keep
RF signal lines as short as possible to minimize losses
and radiation. Use controlled impedance on all high-
frequency traces. The exposed paddle must be sol-
dered evenly to the board’s ground plane for proper
operation. Use abundant vias beneath the exposed
paddle for maximum heat dissipation. Use abundant
ground vias between RF traces to minimize undesired
coupling.
To minimize coupling between different sections of the
IC, the ideal power-supply layout is a star configuration,
which has a large decoupling capacitor at the central
V
CC
node. The V
CC
traces branch out from this node,
with each trace going to separate V
CC
pins of the IC.
Each V
CC
pin must have a bypass capacitor with a low
impedance to ground at the frequency of interest. Do
not share ground vias among multiple connections to
the PCB ground plane.
MAX2112 Evaluation Kit
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