Evaluates: MAX2165
MAX2165 Evaluation Kit
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Connections and Setup
This section provides a step-by-step guide to testing
the basic functionality of the EV kit. Do not turn on the
DC power or RF signal generators until all connec-
tions are completed.
1) Verify jumper shunt JP13 is installed across the top
two posts so when the board is oriented, the Maxim
logo is upright. This pulls the ADDR pin to ground.
2) Set the DC power supply to +2.85V. Connect the
power supply to the VCC (J14) (through an amme-
ter if desired), VCC2 (J5), and GND (J15) terminals
on the EV kit. If available, set the current limit to
125mA. The VCC terminal powers the MAX2165
while the VCC2 terminal, connected by JP7 to VCC,
powers the serial interface and I/Q buffer circuitry.
3) Set both outputs of the dual-output DC power sup-
ply to +2.3V. Connect one output to the BB_AGC
jumper (JP6) and the other output to the RF_AGC
jumper (JP10). Use the pin closest to the IC on both
jumpers.
4) Set the RF signal generator to a 471MHz frequency
and a -85dBm power level, connected to the SMA
connector labeled RFIN on the evaluation board.
5) Connect a 25-pin parallel cable between the PC’s
parallel port and the MAX2165 evaluation board.
6) Install and run the MAX2165 control software.
Software is available for download on the Maxim
website at www.maxim-ic.com.
7) Load the default register settings from the control
software by clicking the Default button at the top of
the screen.
8) The supply current from the +2.85V supply to the
VCC terminal should read approximately 110mA.
Be sure to adjust the power supply to account for
any voltage drop across the ammeter.
9) Connect either the I or Q output to a spectrum ana-
lyzer or to an oscilloscope. Note the 1.5VDC bias at
the output connectors.
10) If using a spectrum analyzer, set it to display frequen-
cies from DC to 5MHz. Set the reference level to
0dBm. Adjust the input power of the signal generator
until the output level of the EV kit reaches -8dBm.
11) If using an oscilloscope, set the input impedance of
the oscilloscope to high impedance and observe
the approximately 1MHz sine wave. Adjust the input
power of the signal generator until the IF output
reaches 500mV
P-P
. Note that this is twice the volt-
age than if the EV kit drives a 50Ω load.
Board Loss Correction
The MAX2165EVKIT also has a buffer at the I and Q
output to allow interfacing with 50Ω test equipment.
These buffers have 50Ω resistors (R23 and R22) in
series with their outputs for back-termination. When the
I and Q outputs from the EV kit are loaded with a 50Ω
test instrument, a voltage divider is formed by the 50Ω
back-termination resistor and the 50Ω test instrument
input impedance, dividing the I/Q output signal by 2.
This loss must be accounted for when measuring gain.
The nominal output level at the IC’s I/Q outputs is
500mV
P-P
(-2dBm) that equates to -8dBm at the I/Q
BNC connectors on the kit when loaded with a 50Ω test
instrument.
Layout Considerations
The MAX2165 EV kit should serve as a close guide for
PCB layout. Keep RF signal lines as short as possible
to minimize losses and radiation. Use controlled imped-
ance on all high-frequency traces. The exposed paddle
must be soldered evenly to the board’s ground plane
for proper operation. Use abundant vias beneath the
exposed paddle and between RF traces to minimize
undesired RF coupling.
To minimize coupling between different sections 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.
