MAX4001EVKIT データシートの表示（PDF） - Maxim Integrated
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MAX4001EVKIT Datasheet PDF : 5 Pages
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MAX4001 Evaluation Kit
Quick Start
Recommended Equipment
• One variable DC power supply capable of supplying
between 2.7V and 5.5V at 50mA
• One signal generator capable of delivering -35dBm
to +10dBm at frequencies between 900MHz and
2.5GHz
• One voltmeter
Procedure
The MAX4001 EV kit is fully assembled and tested.
Follow the steps below to verify board operation. Do
not turn on the power supply until all connections
are completed:
1) Set the variable DC power supply to 3V.
2) Ensure that the variable DC power supply is turned off.
3) Connect the positive terminal of the variable DC
power supply to the pad marked VCC. Connect the
ground return of the variable DC power supply to
the pad marked GND.
4) Set the signal generator to produce an output sig-
nal of 0dBm at a frequency of 2.5GHz.
5) Ensure that the signal generator is turned off.
6) Connect the signal generator to the edge-mount
SMA connector marked RFIN.
7) Connect the positive terminal of the voltmeter to the
pad marked SET. Connect the ground return of the
voltmeter to the pad marked GND.
8) Ensure that shunts are installed across jumpers JU1
and JU2.
9) Ensure that a shunt is placed across pin 1 and pin
2 of jumper JU3.
10) Turn on the variable DC power supply.
11) Turn on/enable the output of the signal generator.
12) Verify with the voltmeter that an output voltage of
1.2V (±5%) is produced between the SET pad and
the GND pad.
Detailed Description
The MAX4001 EV kit is a fully assembled and tested
surface-mount circuit board that evaluates the
MAX4001 RF-detecting controller. The MAX4001 EV kit
includes on-board shutdown control as well as quasi-
measurement mode circuitry to provide an easy
method to evaluate the MAX4001. The RF input utilizes
a 50Ω SMA connector for convenient connection to test
equipment. The MAX4001 EV kit can also be used to
evaluate the MAX4000 and MAX4002 RF-detecting
controllers.
For operation in controller mode, both JU1 and JU2
should be removed. Use a DAC or external precision
voltage supply to apply the set-point voltage to the SET
pad. Connect the RF source (the Power Amplifier (PA)
output through a directional coupler) to the RFIN SMA
connector. Connect the gain control pin of the PA to the
OUT pad. When used in controller mode, a capacitor
(C4) must be present for loop stability (see the Filter
Capacitor Selection section).
To simulate an Automatic Gain-Control (AGC) loop, a
quasi-measurement mode can be implemented where
the MAX4001 delivers an output voltage that is propor-
tional to the log of the input signal (see the Quasi-
Measurement Mode section). To establish the transfer
function of the log amp, the RF input power level should
be swept while the voltage at the SET pad is measured.
This is the simplest method to validate operation of the
evaluation board.
Shutdown Control
Jumper JU3 controls the CMOS-compatible shutdown
pin (SHDN) of the MAX4001, which disables the
MAX4001. Removing the shunt from JU3 allows the
SHDN pin to be driven with an external signal source
connected to the SHDN pad (see Table 1 for shutdown
shunt positions).
Table 1. Shutdown Selection
JUMPER
JU3
SHUNT
POSITION
1–2
2–3
Not Installed
DESCRIPTION
MAX4001 enabled
MAX4001 disabled
SHDN pin driven by an
external signal source
Quasi-Measurement Mode
Enabling the quasi-measurement mode changes the
MAX4001 EV kit function from a PA controller to a log
detector. This mode allows for easy measurement of
RFIN versus the SET voltage and these measurements
can then be used to find the intercept and slope
required for the given application.
Placing shunts across JU1 and JU2 enables the quasi-
measurement mode (which connects the OUT voltage
through an inverting op amp to the SET pin). The quasi-
measurement mode yields a nominal relationship
between RFIN and SET (see Table 2 for quasi-mea-
surement mode shunt positions).
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