Evaluates: MAX9982
MAX9982 Evaluation Kit
2
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Quick Start
The MAX9982 EV kit is fully assembled and factory
tested. Follow the instructions in the
Connections and
Setup
section for proper device evaluation.
Test Equipment Required
Table
1 lists the equipment required to verify the opera-
tion of the MAX9982 EV kit. It is intended as a guide
only, and some substitutions can be made.
Connections and Setup
This section provides a step-by-step guide for testing
the basic functionality of the EV kit. As a general pre-
caution to prevent damaging the outputs by driving
high-VSWR loads,
do not turn on DC power or RF
signals until all connections are made.
This procedure is specific to operation with an RF
input-frequency range of 825MHz to 915MHz, low-side
injected LO for a 100MHz IF. Choose the test frequen-
cy based on the particular system’s frequency plan,
and adjust the following procedure accordingly. See
Figure 1 for the mixer test setup diagram.
1) Calibrate the power meter for 870MHz. For safety
margin, use a power sensor rated to at least
+20dBm, or use padding to protect the power
head as necessary.
2) Connect 3dB pads to DUT ends of each of the
three RF signal generators’ SMA cables. This
padding improves VSWR and reduces the errors
because of mismatch.
3) Use the power meter to set the RF signal genera-
tors according to the following:
• RF signal source: -5dBm into DUT at 870MHz
(approximately -2dBm before the 3dB pad)
• LO1 signal source: 0dBm into DUT at 770MHz
(approxi3dBm before the 3dB pad)
• LO2 signal source: 0dBm into DUT at 771MHz
(approxi3dBm before the 3dB pad)
4) Disable the signal generator outputs.
5) Connect the RF source (with pad) to RF IN.
6) Connect the LO1 and LO2 signal sources to the EV
kit LO inputs.
7) Measure loss in the 3dB pad and the cable that is
connected to IF OUT. Losses are frequency depen-
dent, so test this at 100MHz (the IF frequency).
Use this loss as an offset in all output power/gain
calculations.
8) Connect this 3dB pad to the EV kit’s IF OUT con-
nector, and connect a cable from the pad to the
spectrum analyzer.
9) Set the DC supply to +5.0V, and set a current limit
of approximately 250mA if possible. Disable the
output voltage and connect supply to the EV kit
through a low internal resistance ammeter. Enable
the supply. Re-adjust the supply to get +5.0V at the
EV kit because there will be a voltage drop across
the ammeter when the mixer is drawing current.
10) Select LO1 by leaving LO_SEL (TP3) unconnected
or connecting it to +5V. If left floating, LO_SEL pulls
high by an on-board pullup resistor.
11) Enable the LO and the RF sources.
Testing the Mixer
Adjust the center and span of the spectrum analyzer to
observe the IF output tone at 100MHz. The level should
be at approximately -5.4dBm (2.6dB conversion gain,
3dB pad loss). The spectrum analyzer’s absolute mag-
nitude accuracy is typically no better than ±1dB; there-
fore, use the power meter to get an accurate output
power measurement. There will also be a tone at
99MHz, which is due to the LO signal applied to LO2.
The amount of suppression between the 100MHz and
99MHz signals is the switch isolation.
Connect LO_SEL to GND to select LO2. Observe that
the IF output level at 99MHz increases while the
100MHz level decreases.
Detailed Description
The MAX9982 is a highly integrated downconverter. RF
and LO baluns are integrated on-chip, as well as an LO
buffer and a SPDT LO input select switch. The EV kit cir-
cuit consists mostly of supply decoupling capacitors and
DC-blocking capacitors, allowing for a simple design-in.
Table 1. Test Equipment
EQUIPMENT
QTY
DESCRIPTION
HP E3631A
1
DC power supply
Fluke 75 series II
1
Digital multimeter (ammeter)
HP/Agilent 8648B
3
RF signal generators
HP 437B
1
RF power meter
HP 8561
1
Spectrum analyzer
HP 8482A
1
High-power sensor (power head)
3dB pad
4
3dB attenuators
