19-2907; Rev 1; 11/03
MAX1472 Evaluation Kit
General Description
The MAX1472 evaluation kit (EV kit) allows for a
detailed evaluation of the MAX1472 ASK transmitter. It
enables testing of the device’s RF performance and
requires no additional support circuitry. The RF output
uses a 50Ω matching network and an SMA connector
for convenient connection to test equipment. A reverse-
polarity SMA is also included to connect to a 1/4 wave
whip antenna. The EV kit can also directly interface to
the user’s embedded design for easy data encoding.
The MAX1472 EV kit comes in two versions: a 315MHz
version and a 433.92MHz version. The passive compo-
nents are optimized for these frequencies. These com-
ponents can easily be changed to work at RF frequen-
cies from 300MHz to 450MHz.
For easy implementation into the customer’s design, the
MAX1472 EV kit also features a proven PC board lay-
out, which can be easily duplicated for quicker time-to-
market. The EV kit Gerber files are available for down-
load at www.maxim-ic.com.
o
Proven PC Board Layout
o
Proven Components Parts List
o
Multiple Test Points Provided On-Board
o
Available in 315MHz or 433.92MHz Optimized
Versions
o
Adjustable Frequency Range from 300MHz to
450MHz*
o
Fully Assembled and Tested
o
Can Operate as a Stand-Alone Transmitter with
Included Battery
*Requires
component changes
Features
Evaluates: MAX1472
Ordering Information
PART
MAX1472EVKIT-315
MAX1472EVKIT-433
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
IC PACKAGE
8 SOT23-8
8 SOT23-8
Component List
DESIGNATION
Antenna (315MHz)
QTY
0
DESCRIPTION
315MHz 1/4 wave whip antenna
Lynx ANT-315-CW-RH,
not installed
433MHz 1/4 wave whip antenna
Lynx ANT-433-CW-RH,
not installed
SMA connector top mount,
not installed
Digi-Key J500-ND
Johnson 142-0701-201
Battery holder
MPD BA2032
Coin-cell battery
Panasonic BR2032
15pF
±5%,
50V ceramic
capacitor (0603)
Murata GRM1885C1H150J
7pF
±5%,
50V ceramic
capacitor (0603)
Murata GRM1885C1H7R0J
DESIGNATION
C2 (315MHz)
QTY
1
DESCRIPTION
22pF
±5%,
50V ceramic
capacitor (0603)
Murata GRM1885C1H220J
12pF
±5%,
50V ceramic
capacitor (0603)
Murata GRM1885C1H120J
0.01µF
±10%,
50V ceramic
capacitors (0603)
Murata GRM188R71H103KA01
680pF
±5%,
50V ceramic
capacitor (0603)
Murata GRM1885C1H681J
Not installed
15pF
±5%,
50V ceramic
capacitor (0603)
Murata GRM1885C1H150J
10pF
±5%,
50V ceramic
capacitor (0603)
Murata GRM1885C1H100J
0.47µF +80% - 20%, 16V ceramic
capacitor (0603)
Murata GRM188F51C474Z
Antenna (433MHz)
0
C2 (433MHz)
1
ANTENNA_OUT
1
C3, C10
2
BAT1
Battery
1
1
C4
C5, C16, C18, C19
C6 (315MHz)
1
0
1
C1 (315MHz)
1
C6 (433MHz)
1
C1 (433MHz)
1
C7
1
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX1472 Evaluation Kit
Evaluates: MAX1472
Component List (continued)
DESIGNATION
C11, C12
QTY
2
DESCRIPTION
220pF
±5%,
50V ceramic
capacitors (0603)
Murata GRM1885C1H221J
12pF
±5%,
50V ceramic
capacitors (0603)
Murata GRM1885C1H120J
2-pin headers
Digi-Key S1012-36-ND
or equivalent
Shunts
Digi-Key S9000-ND or equivalent
3-pin headers
Digi-Key S1012-36-ND
or equivalent
27nH
±5%
inductor (0603)
Coilcraft 0603CS-27NXJB
22nH
±5%
inductor (0603)
Coilcraft 0603CS-22NXJB
22nH
±5%
inductor (0603)
Coilcraft 0603CS-22NXJB
15nH
±5%
inductor (0603)
Coilcraft 0603CS-15NXJB
5kΩ potentiometer
BC Components SM4W502
Y1 (433MHz)
1
DESIGNATION
R2
R3
R4
REF_IN
QTY
0
1
1
1
DESCRIPTION
0Ω resistor (0603), any,
not installed
5.1Ω resistor (0603), any
36kΩ
±5%
resistor (0603), any
RP-SMA connector
Lynx CONREVSMA001
SMA connector top mount
Digi-Key J500-ND
Johnson 142-0701-201
Switch
Panasonic EVQ-PJS04K
Test points
Mouser 151-203 or equivalent
MAX1472EKA
ICM7555ISA
Crystal 9.84375 MHz
Hong Kong Crystal
SSL9843750E03FAFZ800 or
Crystek 017000
Crystal 13.56MHz
Hong Kong Crystal
SSM1356000E03FAFZ800 or
Crystek 017001
MAX1472 EV kit PC board
C14, C15
2
JU1, JU4
2
RFOUT
1
JU1
3
SW1
VDD, VSS,
ENABLE, DATA-IN
U1
U2
1
4
1
1
JU2, JU3
2
L1 (315MHz)
L1 (433MHz)
L3 (315MHz)
L3 (433MHz)
R1
1
1
1
1
1
Y1 (315MHz)
1
—
1
Component Suppliers
SUPPLIER
Coilcraft
Crystek
Hong Kong Crystal
Murata
PHONE
800-322-2645
800-237-3061
852-2412 0121
800-831-9172
FAX
847-639-1469
941-561-1025
852-2498 5908
814-238-0490
Connections and Setup
This section provides a step-by-step guide to operating
the EV kit and testing the device’s functionality. Do not
turn on the DC power until all connections are made:
1) Connect a DC supply set to +3.0V, through an
ammeter, to the VDD and VSS terminals on the EV
kit. Do not turn on the supply.
2) Connect the RF OUT SMA connector to the spectrum
analyzer. Set the analyzer to a center frequency of
315MHz (or 433.92MHz) and a span of 1MHz.
3) Turn on the DC supply. The spectrum analyzer
should display a peak of about +10dBm at 315MHz
(or 433.92MHz).
4) Disconnect the spectrum analyzer and connect the
power meter instead. Measure the output power and
also the current draw.
Quick Start
The following procedure allows for proper device
evaluation.
Required Test Equipment
•
•
•
•
2
Regulated power supply capable of providing +3.0V
Spectrum analyzer such as the Agilent 8562E
Optional ammeter for measuring supply current
Power meter such as the Agilent EPM-441A
_______________________________________________________________________________________
MAX1472 Evaluation Kit
5) Calculate the efficiency. This is done using the fol-
lowing equation:
Efficiency = 10 ^ (Pout / 10) / (V x I)
where I is in mA.
For example, the efficiency is 46.6% for an output of
+11dBm, and a current of 9mA (at 3.0V).
Data Input
The MAX1472 EV kit transmits ASK data with data rates
up to 100kbps. JU2 controls whether the MAX1472
transmits CW (jumper pins 1 and 2 connected), an
external data stream (no jumper), or train pulses gener-
ated by the ICM7555 timer (jumper pins 2 and 3 con-
nected). JU4 controls whether the ICM7555 data is
being generated continuously or at the push of SW1.
Evaluates: MAX1472
Layout Issues
A properly designed PC board is an essential part of
any RF/microwave circuit. On high-frequency inputs
and outputs, use controlled-impedance lines and keep
them as short as possible to minimize losses and radia-
tion. At high frequencies, trace lengths that are on the
order of
λ/10
or longer can act as antennas.
Keeping the traces short also reduces parasitic induc-
tance. Generally, 1in of a PC board trace adds about
20nH of parasitic inductance. The parasitic inductance
can have a dramatic effect on the effective inductance.
For example, a 0.5in trace connecting a 100nH induc-
tor adds an extra 10nH of inductance or 10%.
To reduce the parasitic inductance, use wider traces
and a solid ground or power plane below the signal
traces. Also, use low-inductance connections to ground
on all GND pins, and place decoupling capacitors
close to all VDD connections.
The EV kit PC board can serve as a reference design
for laying out a board using the MAX1472.
REF_IN External Frequency Input
For applications where the correct frequency crystal is
not available, it is possible to directly inject an external
frequency through the REF_IN SMA (not provided).
Connect the SMA to a low-phase-noise generator. The
addition of C18 and C19 is necessary (use 0.01µF
capacitors).
Battery Operation
The MAX1472 EV kit can be powered by an external
power supply or by the supplied 3V coin-cell battery.
Set jumper JU3 to connect pins 2 and 3 for battery
operation.
RF Output
The MAX1472 EV kit includes two SMA connectors for RF
output. RFOUT is a standard SMA and is used to connect
the PA output to test equipment. Output is matched to
50Ω. ANTENNA_OUT is a reverse polarity SMA and is
used to connect to a 1/4 wave whip antenna . Note that
resistor R2 (0Ω) needs to be added.
Detailed Description
Enable Control
The MAX1472 can be controlled externally using the
ENABLE connector. The IC draws approximately 1nA
(at room temperature) in shutdown mode. Jumper JU1
is used to control this mode. The shunt can be placed
between pins 1 and 2 for continuous operation.
Remove the JU1 shunt for external control. See Table 1
for jumper function descriptions.
I/O Connections
Table 2 lists all I/O connections.
Table 2. I/O Connectors
SIGNAL
RFOUT
REF_IN
ANTENNA_OUT
VSS
VDD
DATA_IN
ENABLE
RF output
External reference frequency input
Reverse polarity SMA for 1/4 wave
antenna
Ground
3.0V power input
Data input
External power-down control
DESCRIPTION
Table 1. Jumper Functions
JUMPER
JU1
JU1
JU2
JU2
JU2
JU3
JU3
JU4
JU4
STATE
1-2
NC
1-2
2-3
NC
1-2
2-3
1-2
NC
FUNCTION
Normal operation
External power-down control
RF carrier-transmit mode
Transmit pulse-train mode
External data transmit
External supply operation
Battery operation
Continuous data generation
Data controlled by SW1
For additional information and a list of application
notes, consult the Maxim website, www/maxim-ic.com.
_______________________________________________________________________________________
3
MAX1472 Evaluation Kit
Evaluates: MAX1472
Figure 1. MAX1472 EV Kit
50Ω OUTPUT
AT 315MHz AT 433.92MHz
15pF
7pF
22pF
12pF
15pF
10pF
27nH
22nH
22nH
15nH
9.84375MHz 13.56MHz
*
C1
C2
C6
L1
L3
Y1
C14
12pF
Y1
*
C15
12pF
C19
OPEN
REF_IN
1
2
C16
OPEN
*VALUES AFFECTED BY PC BOARD LAYOUT.
1
VDD
VSS
1
R1
5kΩ
C18
OPEN
2
3
V
SS
V
DD
2
PAV
SS
U1
3
7
C7
0.47µF
6
VDD
1
JU1
4
PA
ENABLE
5
ENABLE
TRIGGER
2
TRIGGER DISCHARGE
U2
ICM7555
3
VDD
SW1
4
JU4
RESET
CONTROL
VOLTAGE
5
OUTPUT THRESHOLD
6
7
C11
220pF
XTAL1
XTAL2
8
C5
OPEN
VDD
JU3
C10
0.01µF
1
2
3
GND
V+
VDD
R3
5.1Ω
C4
680pF
C12
220pF
C1
*
C2
*
MAX1472
DATA
L1
*
JU2
DATA_IN
BAT1
8
L3
*
RFOUT
R2
0Ω
ANTENNA_OUT
1
2
C6
*
TRIGGER
R4
36kΩ
TRIGGER
C3
0.01µF
Figure 2. MAX1472 EV Kit Circuit Diagram
4
_______________________________________________________________________________________
MAX1472 Evaluation Kit
Evaluates: MAX1472
Figure 4. MAX1472 EV Kit PC Board Layout—Top Copper
Figure 3. MAX1472 EV Kit Component Placement Guide—Top
Silkscreen
Figure 5. MAX1472 EV Kit PC Board Layout—Bottom Copper
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________
5
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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