19-3726; Rev 0; 5/05
MAX1479 Evaluation Kit
General Description
The MAX1479 evaluation kit (EV kit) allows for a detailed
evaluation of the MAX1479 ASK/FSK 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 polar-
ity 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 MAX1479EV kit comes in two versions: a 315MHz
version and a 433.92MHz version. The passive compo-
nents are optimized for these frequencies. These compo-
nents can easily be changed to work at RF frequencies
from 300MHz to 450MHz.
For easy implementation into the customer’s design, the
MAX1479EV kit also features a proven PC board layout,
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.
♦
Proven PC Board Layout
♦
Proven Components Parts List
♦
Multiple Test Points Provided on Board
♦
Available in 315MHz or 433.92MHz Optimized
Versions
♦
Adjustable Frequency Range from 300MHz to
450MHz*
♦
Fully Assembled and Tested
♦
Can Operate as a Stand-Alone Transmitter with
Included Battery
*Requires
component changes.
Features
Evaluates: MAX1479
Ordering Information
PART
MAX1479EVKIT-315
MAX1479EVKIT-433
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
IC PACKAGE
16 Thin QFN
16 Thin QFN
Component List
DESIGNATION QTY
C1, C6
(315MHz)
2
DESCRIPTION
15pF ±5%, 50V ceramic capacitors
(0603)
Murata GRM1885C1H150J
6.8pF ±0.5pF, 50V ceramic capacitors
(0603) C0G
Murata GRM1885C1H6R8D
22pF ±5%, 50V ceramic capacitor
(0603) C0G
Murata GRM1885C1H220J
10pF ±5%, 50V ceramic capacitor
(0603) C0G
Murata GRM1885C1H100J
0.01µF ±10%, 50V ceramic capacitors
(0603)
Murata GRM188R71H103KA01
680pF ±5%, 50V ceramic capacitor
(0603) C0G
Murata GRM1885C1H681J
Not installed
L1 (433MHz)
1
DESIGNATION QTY
C7, C9
2
DESCRIPTION
0.47µF +80/-20%, 16V ceramic
capacitors (0603) Y5V
Murata GRM188F51C474Z
220pF ±5%, 50V ceramic capacitors
(0603)
Murata GRM1885C1H221J
2.2pF ±0.5pF, 50V ceramic capacitor
(0603) C0G
Murata GRM1885C1H2R2D
1.0pF ±0.5pF, 50V ceramic capacitor
(0603) C0G
Murata GRM1885C1H1R0D
100pF ±5%, 50V ceramic capacitors
(0603)
Murata GRM1885C1H101J
3-pin headers
Digi-Key S1012-36-ND or equivalent
27nH ±5% inductor (0603)
Coilcraft 0603CS-27NXJB
22nH ±5% inductor (0603)
Coilcraft 0603CS-22NXJB
C1, C6
(433MHz)
2
C8, C11, C12
3
C2 (315MHz)
1
C13 (315MHz)
1
C2 (433MHz)
1
C13 (433MHz)
1
C3, C10
2
C14, C15
2
C4
C5, C16,
C18, C19
1
JU1–JU10
L1 (315MHz)
10
1
0
________________________________________________________________
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.
MAX1479 Evaluation Kit
Evaluates: MAX1479
Component List (continued)
DESIGNATION QTY
L2 (315MHz)
L2 (433MHz)
R1
R2
R3
R4
Antenna
(315MHz)
1
1
1
0
1
1
0
DESCRIPTION
22nH ±5% inductor (0603)
Coilcraft 0603CS-22NXJB
18nH ±5% inductor (0603)
Coilcraft 0603CS-18NXJB
5kΩ potentiometer
BC Components SM4W502
0Ω resistor (0603), any,
not installed
5.1Ω ±5% resistor (0603), any
0Ω resistor (0603), any
315MHz 1/4-wave whip antenna,
not provided
Lynx ANT-315-CW-RH
433MHz 1/4-wave whip antenna,
not provided
Lynx ANT-433-CW-RH
RP-SMA connector
Linx CONREVSMA001
Battery holder
MPD BA2032
Coin-cell battery
Panasonic BR2032
Y1 (433MHz)
1
RF_OUT
U1
VDD, VSS,
ENABLE,
DATA_IN,
CKOUT
1
1
DESIGNATION QTY
REF_IN
1
DESCRIPTION
SMA connector top mount, not installed
Digi-Key J500-ND
Johnson 142-0701-201
SMA connector top mount
Digi-Key J500-ND
Johnson 142-0701-201
MAX1479ATE
Test points
Mouser 151-203 or equivalent
5
Y1 (315MHz)
1
Antenna
(433MHz)
ANTENNA_OUT
BAT1
Battery
1
Crystal 9.84375MHz
Hong Kong Crystal
SSL9843750E03FAFZ800 or
Crystek 017000
Crystal 13.56MHz
Hong Kong Crystal
SSM1356000E03FAFZ800 or
Crystek 017001
Shunt (JU1)
Digi-Key S9000-ND or equivalent
MAX1479 EV kit PC board
1
1
1
—
—
10
1
Connections and Setup
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
Note:
Indicate you are using the MAX1479 when contacting
these manufacturers.
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
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 spec-
trum 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.
5) Calculate the efficiency. This is done using the
following equation:
Efficiency = 10ˆ
(P
OUT
/10)/(V x I)
For example, for a +10.8dBm output, and a
10.9mA (at 3.0V) current, the efficiency is 37%.
_______________________________________________________________________________________
MAX1479 Evaluation Kit
Layout Issues
A properly designed PC board is an essential part of any
RF/microwave circuit. On high-frequency inputs and out-
puts, use controlled-impedance lines and keep them as
short as possible to minimize losses and radiation. 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 inductor
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 MAX1479.
Data Input
The MAX1479 EV kit transmits ASK and FSK data with
data rates of up to 100kbps (ASK) or 20kbps (FSK).
JU2 controls whether the MAX1479 transmits the ASK
carrier frequency (or the FSK high frequency), turns off
the PA (or transmits the FSK low frequency), or trans-
mits an external data stream. See Table 1.
Evaluates: MAX1479
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 MAX1479 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 MAX1479 EV kit includes two SMA connectors for
RF output. RF_OUT 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 the 1/4-wave whip
antenna (not supplied). Note that resistor R2 (0Ω)
needs to be added.
Detailed Description
Power-Down Control
The MAX1479 can be controlled externally using the
ENABLE connector. The IC draws approximately 0.2nA
(at room temperature) in shutdown mode. Jumper JU1
is used to control this mode. The shunt can be placed
between pins 1 and 2 to enable the device. Remove
the JU1 shunt for external control. See Table 1 for
jumper function descriptions.
Modulation Mode Input
Jumper JU4 sets the mode of transmission. Set jumper
JU4 to connect pins 1 and 2 for FSK mode, 2 and 3 for
ASK mode.
Table 1. JU1 Through JU4 Jumpers
Function
JUMPER
JU1
STATE
1-2
2-3
N.C.
1-2
JU2
2-3
N.C.
JU3
JU4
1-2
2-3
1-2
2-3
FUNCTION
RF carrier transmit enable
Power-down mode
External power-down control
RF carrier transmit mode (ASK),
FSK high frequency (FSK)
PA off, PLL ON (ASK),
FSK low frequency (FSK)
External data transmit
External supply operation
Battery operation
FSK mode
ASK mode
FSK Frequency Deviation
The FSK deviation is set by jumpers JU5 through JU7.
The maximum deviation depends on the PC board para-
sitics. The EV kit max is around 50kHz (315MHz). If very
large FSK frequency deviations are desired, use a crystal
with a larger motional capacitance and/or reduce PC
board parasitic capacitances. One way to reduce para-
sitic capacitances on the EV kit is to remove C14, C15,
and C16 and move the crystal closer to the IC.
_______________________________________________________________________________________
3
MAX1479 Evaluation Kit
Evaluates: MAX1479
Table 2. Clock-Divider Settings
JUMPER
SETTING
1-2
1-2
1-2
JU5
1-2
2-3
2-3
2-3
2-3
JU6
JUMPER
SETTING
1-2
1-2
2-3
2-3
1-2
1-2
2-3
2-3
JU7
JUMPER
SETTING
1-2
2-3
1-2
2-3
1-2
2-3
1-2
2-3
FUNCTION
Max deviation
7/8 x max deviation
3/4 x max deviation
5/8 x max deviation
1/2 x max deviation
3/8 x max deviation
1/4 x max deviation
1/8 x max deviation
Clock Output
Jumpers JU8 and JU9 set the divider ratio for the clock
output. See Table 3 for the settings.
I/O Connections
Table 5 is a list of all I/O connections.
Table 5. I/O Connectors
SIGNAL
DESCRIPTION
RF output
External reference frequency input
Reverse polarity SMA for 1/4-wave antenna
Ground
Power-supply input
Data input
Power-down control
Buffered clock output
RF_OUT
REF_IN
ANTENNA_OUT
VSS
VDD
DATA_IN
ENABLE
CLKOUT
Table 3. Clock Divider Settings
JUMPER
SETTING
1-2
1-2
JU8
2-3
2-3
JU9
JUMPER
SETTING
1-2
2-3
1-2
2-3
FUNCTION
f
XTAL
/16
f
XTAL
/8
f
XTAL
/4
Logic 0
output
Envelope Shaping
Jumper JU10 sets envelope shaping for a more gentle
turn-on/turn-off of the PA in ASK mode. Set jumper
JU10 to connect pins 2 and 3 to allow for envelope
shaping. See Table 4 for settings.
For additional information and a list of application
notes, consult the www.maxim-ic.com website.
Table 4. JU10 Jumper Function
JUMPER
JU10
STATE
1-2
2-3
FUNCTION
No envelope shaping
Envelope shaping
4
_______________________________________________________________________________________
MAX1479 Evaluation Kit
Evaluates: MAX1479
C14
100pF
Y1*
C15
100pF
C19
OPEN REF_IN
1
2
50Ω OUTPUT
*
C1
C2
C6
C13
L1
†
L2
†
AT 315MHz
15pF
22pF
15pF
2.2pF
27nH
22nH
9.84375MHz
AT 433.92MHz
6.8pF
10pF
6.8pF
1.0pF
22nH
18nH
13.56MHz
C16
OPEN
14
C18
OPEN
VDD
1
2
3
XTAL1
XTAL2
15
Y1
†
USE WIRE-WOUND INDUCTORS ONLY.
C5
OPEN
GND
16
VSS
JU4
2
MODE
U1
MAX1479
VDD
DATA_IN
1
2
3
VDD_PA
VDD
ENABLE
1
2
3
1
2
3
1
2
C12
220pF
L2*
C4
680pF
JU10
6
C9
0.47µF
C8
220pF
V
DD
3
1
C7
0.47µF
C11
220pF
C10
0.01µF
R3
5.1Ω
VDD
JU3
1
2
3
VDD
JU2
DIN
R4
0Ω
C3
0.01µF
BAT1
JU1
4
ENABLE
ROUT
7
3
R1
5kΩ
L1*
C1*
CKOUT
5
CLKOUT
CLK0
9
CLK1
10
VDD
JU7
1
2 3
VDD
JU6
1
2 3
DEV0
11
DEV1
12
VDD
PAOUT
DEV2
13
8
C13*
C2*
C6*
R2
OPEN
RF_OUT
1
2
VDD
JU9
1
2 3
VDD
JU8
JU5
1
2 3
ANTENNA_OUT
1
2
1
2 3
Figure 1. MAX1479 EV Kit Schematic
_______________________________________________________________________________________
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
