19-2960; Rev 1; 5/05
MAX1473 Evaluation Kit
General Description
The MAX1473 evaluation kit (EV kit) allows for a
detailed evaluation of the MAX1473 superheterodyne
receiver. It enables testing of the device’s RF perfor-
mance and requires no additional support circuitry. The
RF input uses a 50Ω matching network and an SMA
connector for convenient connection to test equipment.
The EV kit can also directly interface to the user’s
embedded design for easy data decoding.
The MAX1473 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. In addition, the 5kbps
data rate received can be adjusted from 0 to 100kbps
by changing two more components.
For easy implementation into the customer’s design, the
MAX1473 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.
♦
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 Receiver with
Addition of an Antenna
*Requires component changes
Features
Evaluates: MAX1473
Ordering Information
PART
MAX1473EVKIT-315
MAX1473EVKIT-433
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
IC PACKAGE
28 TSSOP
28 TSSOP
Component List
DESIGNATION QTY
C1, C2
2
DESCRIPTION
0.01µF
±10%
ceramic capacitors (0603)
Murata GRM188R71H103KA01
1500pF
±10%,
50V X7R ceramic
capacitor (0603)
Murata GRM188R71H152KA01
0.47µF +80% - 20% ceramic
capacitor (0603)
Murata GRM188F51C474ZA01
470pF
±5%
ceramic capacitor (0603)
Murata GRM1885C1H471JA01
220pF
±
5% ceramic capacitors (0603)
Murata GRM1885C1H221JA01
100pF
±
5% ceramic capacitors (0603)
Murata GRM1885C1H101JA01
4pF
±
0.1pF ceramic capacitor (0603)
Murata GRM1885C1H4R0BZ01
2.2pF
±
0.1pF ceramic capacitor (0603)
Murata GRM1885C1H2R2BD01
0.1µF
±5%
ceramic capacitors (0603)
Murata GRM188R71C104KA01
Not installed
DESIGNATION QTY
C14, C15
2
DESCRIPTION
15pF
±5%,
50V ceramic capacitors
(0603)
Murata GRM1885C1H150JZ01
0.01µF +80% - 20% ceramic
capacitor (0603), not installed
Murata GRM188R71H103KA01
0Ω resistor (0603)
SMA connector edge mount, not
installed
Johnson 142-0701-801
3-pin headers
Digi-Key S1012-36-ND or equivalent
2-pin header
Not installed
Shorted
Shunts (JU1)
Digi-Key S9000-ND or equivalent
27nH
±5%
inductor (0603)
Coilcraft 0603CS-27NXJB
C3
1
C17
C21
F_IN
JU1, JU2, JU5,
JU6
JU7
JU3, JU4
JU8
—
L1 (315MHz)
0
1
0
C4
1
C5
C6, C10
C7, C8, C11
C9 (315MHz)
C9 (433MHz)
C12, C20
C13, C16, C18,
C19
1
2
3
1
1
2
0
4
1
0
1
5
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.
MAX1473 Evaluation Kit
Evaluates: MAX1473
Component List (continued)
DESIGNATION QTY
L1 (433MHz)
L2 (315MHz)
L2 (433MHz)
L3
1
1
1
1
DESCRIPTION
15nH
±5%
inductor (0603)
Coilcraft 0603CS-15NXJB
120nH
±5%
inductor (0603)
Coilcraft 0603CS-R12XJB
56nH
±5%
inductor (0603)
Coilcraft 0603CS-56NXJB
15nH
±5%
inductor (0603)
Murata LQG18HN15NJ00
SMA connector top mount, not installed
Digi-Key J500-ND
Johnson 142-0701-201
5.1kΩ resistor (0603), any
Resistor (0603), not installed
270Ω resistor (0603), any, not installed
10kΩ resistor (0603), any
10pF
±5%,
50V ceramic capacitor (0603)
Murata GRM1885C1H100JZ01
10kΩ resistor (0603), any
Y1 (433MHz)
1
RF IN
TP2, TP4–TP12
VDD, GND,
SHDN,
DATA_OUT,
TP3
1
0
DESIGNATION QTY
R9
1
DESCRIPTION
1000pF
±10%,
50V X7R ceramic
capacitor (0603)
Murata GRM188R71H102KA01
SMA connector top mount
Digi-Key J500-ND
Johnson 142-0701-201
Not installed
Test points
Mouser 151-203 or equivalent
Crystal 4.754687MHz
Hong Kong Crystal
SSL4754687E03FAFZ8A0 or
Crystek 016867
Crystal 6.6128MHz
Hong Kong Crystal
SSL6612813E03FAFZ8A0 or Crystek
016868
10.7MHz ceramic filter
Murata SFTLA10M7FA00-B0
MAX1473EUI
MAX1473 EV kit PC board
5
MIX OUT
R1
R2, R4, R6
R3
R5
R7
R8
0
1
0
0
1
1
1
Y1 (315MHz)
1
Quick Start
The following procedure allows for proper device evalu-
ation.
Y2
U1
—
1
1
1
Required Test Equipment
• Regulated power supply capable of providing +3.3V
• RF signal generator capable of delivering from
-120dBm to 0dBm of output power at the operating
frequency, in addition to AM or pulse-modulation
capabilities (Agilent E4420B or equivalent)
• Optional ammeter for measuring supply current
• Oscilloscope
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 or RF signal generator until all
connections are made:
1) Connect a DC supply set to +3.3V (through an
ammeter, if desired) to the VDD and GND terminals
on the EV kit. Do not turn on the supply.
2) Connect the RF signal generator to the RF_IN SMA
connector. Do not turn on the generator output. Set
the generator for an output frequency of 315MHz (or
433.92MHz) at a power level of -100dBm. Set the
modulation of the generator to provide a 2kHz 100%
2
AM-modulated square wave (or a 2kHz pulse-modu-
lated signal).
3) Connect the oscilloscope to test point TP3.
4) Turn on the DC supply. The supply current should
read approximately 5mA.
5) Activate the RF generator’s output without modulation.
The scope should display a DC voltage that varies
from approximately 1.2V to 2.0V as the RF generator
amplitude is changed from -115dBm to 0dBm. (Note:
At an input amplitude of around -60dBm, this DC
voltage will drop suddenly to about 1.5V and then
rise again with increasing input amplitude. This is
normal; the AGC is turning on the LNA gain reduc-
tion resistor).
6) Set the RF generator to -100dBm. Activate the RF
generator’s modulation and set the scope’s coupling
to AC. The scope now displays a lowpass-filtered
square wave at TP3 (filtered analog baseband data).
Use the RF generator’s LF OUTPUT (modulation out-
put) to trigger the oscilloscope.
7) Monitor the DATA_OUT terminal and verify the pres-
ence of a 2kHz square wave.
_______________________________________________________________________________________
MAX1473 Evaluation Kit
Additional Evaluation
1) With the modulation still set to AM, observe the
effect of reducing the RF generator’s amplitude on
the DATA_OUT terminal output. The error in this
sliced digital signal increases with reduced RF sig-
nal level. The sensitivity is usually defined as the
point at which the error in interpreting the data (by
the following embedded circuitry) increases beyond
a set limit (BER test).
2) With the above settings, a 315MHz-tuned EV kit
should display a sensitivity of about -117dBm (0.2%
BER) while a 433.92MHz kit displays a sensitivity of
about -115dBm (0.2% BER).
Note:
The above sensi-
tivity values are given in terms of average peak
power is 3dB higher.
3) Capacitors C5 and C6 are used to set the corner fre-
quency of the 2nd-order lowpass Sallen-Key data fil-
ter. The current values were selected for bit rates up
to 5kbps. Adjusting these values accommodates
higher data rates (refer to the MAX1473 data sheet
for more details).
for continuous shutdown, or pins 1 and 2 for continuous
operation. Remove the JU1 shunt for external control.
Table 1 describes jumper functions.
Evaluates: MAX1473
Power Supply
The MAX1473 can operate from 3.3V or 5V supplies.
For 5V operation, remove JU7 before connecting the
supply to VDD. For 3.3V operation, connect JU7.
IF Input/Output
The 10.7MHz IF can be monitored with the help of a
spectrum analyzer using the MIX_OUT SMA connector
(not provided). Remove the ceramic filter for such a
measurement and include R3 (270Ω) and C17 (0.01µF)
to match the 330Ω mixer output with the 50Ω spectrum
analyzer. Jumper JU3 needs to connect pins 1 and 2. It
is also possible to use the MIX_OUT SMA connector to
inject an external IF as a means of evaluating the base-
band data slicing section. Jumper JU3 needs to con-
nect pins 2 and 3.
F_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 F_IN SMA connector (not provid-
ed). Connect the SMA connector to a function genera-
tor. The addition of C18 and C19 is necessary (use
0.01µF capacitors).
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 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 MAX1473. All required
components have been enclosed in a 1.25in
✕
1.25in
square, which can be directly “inserted” into the appli-
cation circuit.
AGC Control
Jumper JU5 controls whether the AGC is enabled.
Connect pins 2 and 3 to enable the AGC.
Crystal Select
Jumper JU2 controls the crystal divide ratio.
Connecting pins 1 and 2 sets the divide ratio to 64,
while connecting pins 2 and 3 sets the ratio to 32. This
determines the frequency of the crystal to be used.
Image Rejection Frequency Select
A unique feature of the MAX1473 is its ability to vary at
which frequency the image rejection is optimized. JU6
allows the selection of three possible frequencies:
315MHz, 375MHz, and 433.92MHz. See Table 1 for set-
tings.
Test Points and I/O Connections
Additional test points and I/O connectors are provided
to monitor the various baseband signals and for exter-
nal connections. See Tables 2 and 3 for a description.
For additional information and a list of application
notes, consult the www.maxim-ic.com website.
Detailed Description
Power-Down Control
The MAX1473 can be controlled externally using the
SHDN connector. The IC draws approximately 1.25µA
in shutdown mode. Jumper JU1 is used to control this
mode. The shunt can be placed between pins 2 and 3
_______________________________________________________________________________________________________
3
MAX1473 Evaluation Kit
Evaluates: MAX1473
Table 1. Jumper Functions
JUMPER
JU1
JU1
JU1
JU2
JU2
JU3
JU3
JU3
JU4
JU4
JU5
JU5
JU6
JU6
JU6
JU7
JU7
STATE
1-2
2-3
NC
2-3
1-2
1-2
2-3
NC
1-2
2-3
1-2
2-3
1-2
2-3
NC
1-2
NC
FUNCTION
Normal operation
Power-down mode
External power-down control
Crystal divide ratio = 32
Crystal divide ratio = 64
Mixer output to MIX_OUT
External IF input
Normal operation
Uses PDOUT for faster receiver
startup
GND connection for peak detector
filter
Disables AGC
Enables AGC
IR centered at 433MHz
IR centered at 315MHz
IR centered at 375MHz
Connect VDD to +3.3V supply
Connect VDD to +5.0V supply
Table 3. I/O Connectors
SIGNAL
RF_IN
F_IN
MIX_OUT
GND
VDD
DATA_OUT
SHDN
RF input
External reference frequency input
IF input/output
Ground
Supply input
Sliced data output
External power-down control
DESCRIPTION
Table 2. Test Points
TP
2
3
4
5
6
7
8
9
10
11
12
Data filter output
Peak detector out
+3.3V
GND
Data filter feedback node
Data out
Power-down select input
VDD
AGC control
Crystal select
DESCRIPTION
Data slicer negative input
Figure 1. MAX1473 EV Kit
4
_______________________________________________________________________________________
MAX1473 Evaluation Kit
Evaluates: MAX1473
*
C9
L1
L2
Y1
AT 315MHz
4pF
27nH
120nH
4.754689MHz
AT 433.92MHz
2.2pF
15nH
56nH
6.6128MHz
C18
OPEN
+3.3V
C12
0.1µF
1
2
XTAL1
AV
DD
XTAL2
PWRDN
PDOUT
C16
OPEN
C14
15pF
Y1
*
C15
15pF
C19
OPEN
F_IN
+3.3V
JU7
C20
0.1µF
VDD
VDD
TP10
TP5
VDD
28
27
26
R2
OPEN
3
4
L3
15nH
+3.3V
7
C2
0.01µF
5
6
LNAIN
LNASRC
AGND
LNAOUT
AV
DD
R9
1000pF
8
MIXIN1
MIXIN2
22
21
20
R1
5.1kΩ
TP3
C6
220pF
DSN
TP2
C4
0.47µF
C5
470pF
JU8
SHORT
R6
OPEN
U1
MAX1473
DSP
23
C21
0Ω
R7
10pF
DATAOUT
V
DD5
25
24
V
DD
C13
OPEN
TP4
1
2 JU4
3
JU1
DSN
1
2
3
SHDN
TP9
TP8
R5
10kΩ
DATA_OUT
RF_IN
C7
100pF
L2
*
L1
*
+3.3V
C9
*
C11
100pF
C10
220pF
C8
100pF
9
DFFB
OPP
GND
TP6
DSN
TP7
+3.3V
10
1
3
2
JU6
11
12
13
AGND
IR_SEL
MIXOUT
DFO
IFIN2
19
18
17
C3
1500pF
R8
10kΩ
+3.3V
+3.3V
JU2 1
2
1
3
3
R3
JU3 OPEN
2
R4
OPEN
C17
OPEN
MIX_OUT
+3.3V
DGND
14 DV
DD
C1
0.01µF
IN
1
GND
2
IFIN1
16
XT_SEL
15
AGC_OFF
Y2
OUT 10.7MHz
3
JU5 1
TP12
2
3
TP11
Figure 2. MAX1473 EV Kit Schematic
_______________________________________________________________________________________
5
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