19-3353; Rev 1; 6/09
KIT
ATION
EVALU
BLE
AVAILA
300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter
General Description
Features
o
ETSI-Compliant EN300 220
o
+2.1V to +3.6V Single-Supply Operation
o
Supports ASK, OOK, and FSK Modulations
o
Adjustable FSK Shift
o
+10dBm Output Power into 50Ω Load
o
Low Supply Current (6.7mA in ASK Mode,
and 10.5mA in FSK Mode)
o
Uses Small Low-Cost Crystal
o
Small 16-Pin TQFN Package
o
Fast-On Oscillator—200µs Startup Time
o
Programmable Clock Output
MAX1479
The MAX1479 crystal-referenced phase-locked-loop
(PLL) VHF/UHF transmitter is designed to transmit ASK,
OOK, and FSK data in the 300MHz to 450MHz frequency
range. The MAX1479 supports data rates up to 100kbps
in ASK mode and 20kbps in FSK mode (both
Manchester coded). The device provides an adjustable
output power of more than +10dBm into a 50Ω load. The
crystal-based architecture of the MAX1479 eliminates
many of the common problems of SAW-based transmit-
ters by providing greater modulation depth, faster fre-
quency settling, higher tolerance of the transmit
frequency, and reduced temperature dependence.
These improvements enable better overall receiver per-
formance when using the MAX1479 together with a
superheterodyne receiver such as the MAX1470,
MAX1471, MAX1473, or MAX7033.
The MAX1479 is available in a 16-pin TQFN package
(3mm x 3mm) and is specified for the automotive tem-
perature range from -40°C to +125°C.
Applications
Remote Keyless Entry
Tire Pressure Monitoring
Security Systems
Radio-Controlled Toys
Wireless Game Consoles
Wireless Computer Peripherals
Wireless Sensors
RF Remote Controls
Garage Door Openers
PART
MAX1479ATE+
Ordering Information
TEMP RANGE
-40°C to +125°C
PIN-PACKAGE
16 TQFN-EP*
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
Typical Application Circuit appears at end of data sheet.
Functional Diagram
XTAL2
XTAL1
DEV2
GND
Pin Configuration
XTAL2
XTAL1
DEV2
TOP VIEW
GND
16
15
14
13
V
DD
1
CRYSTAL
DRIVER
16
DEVIATION
12 DEV1
15
14
13
12
DEV1
DEV0
CLK1
CLK0
V
DD
PD/CP
MODE
2
ASK
FSK
DIN
3
DIVIDE
BY 32
VCO
LOOP
FILTER
11 DEV0
1
2
3
4
5
CLKOUT
MODE
DIN
ENABLE
MAX1479
EP*
11
10
9
10 CLK1
MAX1479
ENABLE
4
CLOCK
DIVIDER
ENVELOPE
SHAPING
PA
9
CLK0
6
V
DD_
PA
7
ROUT
8
PAOUT
5
CLKOUT
6
V
DD_
PA
7
ROUT
8
PAOUT
TQFN
(3mm x 3mm)
*CONNECT EP TO GND.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter
MAX1479
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND .............................................................-0.3V to +4V
All Other Pins to GND ................................-0.3V to (V
DD
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TQFN (derate 14.7mW/°C above +70°C).........1176.5mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(Typical
Application Circuit,
all RF inputs and outputs are referenced to 50Ω, V
DD
= +2.1V to +3.6V, V
ENABLE
= V
DD
, T
A
= -40°C to
+125°C, unless otherwise noted. Typical values are at V
DD
= +2.7V, T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
Supply Voltage
SYMBOL
V
DD
PA off, V
DIN
at
0% duty cycle
(ASK or FSK)
(Note 2)
Supply Current
I
DD
V
DIN
at 50% duty
cycle (ASK)
(Notes 3, 4)
V
DIN
at 100%
duty cycle (FSK)
Standby Current
DIGITAL INPUTS AND OUTPUTS
Data Input High
Data Input Low
Maximum Input Current
Output Voltage High
Output Voltage Low
V
IH
V
IL
I
IN
V
OH
V
OL
CLKOUT, load = 10kΩ || 10pF (Note 4)
CLKOUT, load = 10kΩ || 10pF (Note 4)
V
DD
-
0.25
0.25
(Note 2)
(Note 2)
20
V
DD
-
0.25
0.25
V
V
µA
V
V
I
STDBY
V
ENABLE
< V
IL
f
RF
= 315MHz
f
RF
= 433MHz
f
RF
= 315MHz
f
RF
= 433MHz
f
RF
= 315MHz (Note 2)
f
RF
= 433MHz (Note 4)
T
A
= +25°C
T
A
< +85°C (Note 4)
T
A
< +125°C (Note 2)
CONDITIONS
MIN
2.1
2.9
3.3
6.7
7.3
10.5
11.4
0.2
120
700
300
1600
nA
TYP
MAX
3.6
4.3
4.8
10.7
11.4
17.1
18.1
mA
UNITS
V
2
_______________________________________________________________________________________
300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter
AC ELECTRICAL CHARACTERISTICS
(Typical
Application Circuit,
all RF inputs and outputs are referenced to 50Ω, V
DD
= +2.1V to +3.6V, V
ENABLE
= V
DD
, T
A
= -40°C to
+125°C, unless otherwise noted. Typical values are at V
DD
= +2.7V, T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYSTEM PERFORMANCE
Frequency Range
Turn-On Time (Note 5)
Maximum Data Rate (Note 4)
Maximum FSK Frequency
Deviation
Output Power (Note 2)
Transmit Efficiency with CW Tone
(Note 7)
Transmit Efficiency at 50% Duty
Cycle
PHASE-LOCKED-LOOP PERFORMANCE
VCO Gain
K
VCO
f
RF
= 315MHz
Phase Noise
f
RF
= 433MHz
Maximum Carrier Harmonics
Reference Spur
Loop Bandwidth
Crystal Frequency Range
Crystal Tolerance
Crystal Load Capacitance
Clock Output Frequency
C
LOAD
(Note 8)
Determined by CLK0 and CLK1; see Table 1
BW
f
XTAL
f
RF
= 315MHz
f
RF
= 433MHz
f
OFFSET
= 100kHz
f
OFFSET
= 1MHz
f
OFFSET
= 100kHz
f
OFFSET
= 1MHz
280
-75
-98
-74
-98
-50
-45
-40
300
F
RF
/ 32
50
4.5
F
XTAL
/N
dBc
dBc
kHz
MHz
ppm
pF
MHz
dBc/Hz
MHz/V
P
OUT
f
RF
t
ON
(Note 2)
Settle to within 50kHz
Settle to within 5kHz
ASK mode (Manchester coded)
FSK mode (Manchester coded)
DEV[2:0] = 111
(Note 6)
f
RF
= 315MHz
f
RF
= 433MHz
6.8
2.7
300
200
350
100
20
55
80
10
5.3
12.2
35
34
27
25
16.1
%
%
12.0
dBm
450
MHz
µs
kbps
kHz
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1479
T
A
= +25°C, V
DD
= +2.7V
T
A
= +125°C, V
DD
= +2.1V
T
A
= -40°C, V
DD
= +3.6V
f
RF
= 315MHz
f
RF
= 433MHz
f
RF
= 315MHz
f
RF
= 433MHz
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Supply current, output power, and efficiency are greatly dependent on board layout and PAOUT match.
100% tested at T
A
= +125°C. Guaranteed by design and characterization over temperature.
50% duty cycle at 10kHz ASK data (Manchester coded).
Guaranteed by design and characterization, not production tested.
V
ENABLE
= V
IL
to V
ENABLE
= V
IH
. f
OFFSET
is defined as the frequency deviation from the desired carrier frequency.
Dependent on crystal and PCB trace capacitance.
V
ENABLE
> V
IH
, V
DATA
> V
IH
, Efficiency = P
OUT
/(V
DD
x I
DD
).
Dependent on PCB trace capacitance.
_______________________________________________________________________________________
3
300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter
MAX1479
Typical Operating Characteristics
(Typical
Application Circuit,
V
DD
= +2.7V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX1479 toc01
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX1479 toc02
SUPPLY CURRENT vs. SUPPLY VOLTAGE
14
SUPPLY CURRENT (mA)
13
12
T
A
= +25°C
11
10
9
T
A
= +85°C
T
A
= +125°C
f
RF
= 433MHz
PA ON
T
A
= -40°C
MAX1479 toc03
15
14
SUPPLY CURRENT (mA)
13
12
T
A
= +25°C
11
10
9
8
7
2.1
2.4
2.7
3.0
3.3
T
A
= +85°C
T
A
= +125°C
f
RF
= 315MHz
PA ON
T
A
= -40°C
10.0
9.5
9.0
SUPPLY CURRENT (mA)
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
T
A
= -40°C
T
A
= +125°C
T
A
= +25°C
T
A
= +85°C
f
RF
= 315MHz
PA 50% DUTY CYCLE AT 10kHz
15
8
7
3.3
3.6
2.1
2.4
2.7
3.0
3.3
3.6
3.6
2.1
2.4
2.7
3.0
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX1479 toc04
SUPPLY CURRENT vs. OUTPUT POWER
MAX1479 toc05
SUPPLY CURRENT vs. OUTPUT POWER
11
10
SUPPLY CURRENT (mA)
9
8
7
6
5
4
3
2
50% DUTY CYCLE
PA ON
f
RF
= 433MHz
MAX1479 toc06
10.0
9.5
9.0
SUPPLY CURRENT (mA)
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
2.1
2.4
2.7
3.0
3.3
T
A
= -40°C
T
A
= +125°C
T
A
= +25°C
T
A
= +85°C
f
RF
= 433MHz
PA 50% DUTY CYCLE AT 10kHz
12
11
10
SUPPLY CURRENT (mA)
9
8
7
6
5
4
3
2
50% DUTY CYCLE
PA ON
f
RF
= 315MHz
12
3.6
-14
-10
-6
-2
2
6
10
-14
-10
-6
-2
2
6
10
SUPPLY VOLTAGE (V)
AVERAGE OUTPUT POWER (dBm)
AVERAGE OUTPUT POWER (dBm)
SUPPLY CURRENT AND OUTPUT POWER
vs. EXTERNAL RESISTOR
18
16
SUPPLY CURRENT (mA)
14
12
10
8
6
4
2
0.1
1
10
100
1k
10k
EXTERNAL RESISTOR (Ω)
CURRENT
f
RF
= 315MHz
PA ON
POWER
MAX1479 toc07
SUPPLY CURRENT AND OUTPUT POWER
vs. EXTERNAL RESISTOR
16
12
SUPPLY CURRENT (mA)
OUTPUT POWER (dBm)
8
4
0
-4
-8
-12
-16
18
16
14
12
10
8
6
4
2
0.1
1
10
100
1k
10k
EXTERNAL RESISTOR (Ω)
CURRENT
f
RF
= 433MHz
PA ON
POWER
MAX1479 toc08
16
12
OUTPUT POWER (dBm)
8
4
0
-4
-8
-12
-16
4
_______________________________________________________________________________________
300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter
Typical Operating Characteristics (continued)
(Typical
Application Circuit,
V
DD
= +2.7V, T
A
= +25°C, unless otherwise noted.)
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX1479 toc09
MAX1479
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX1479 toc10
OUTPUT POWER vs. SUPPLY VOLTAGE
f
RF
= 315MHz
PA ON
ENVELOPE SHAPING
DISABLED
T
A
= +25°C
MAX1479 toc11
16
14
OUTPUT POWER (dBm)
12
10
T
A
= +85°C
8
T
A
= +125°C
6
4
2.1
2.4
2.7
3.0
3.3
f
RF
= 315MHz
PA ON
T
A
= -40°C
T
A
= +25°C
16
14
OUTPUT POWER (dBm)
12
10
T
A
= +85°C
8
T
A
= +125°C
6
4
f
RF
= 433MHz
PA ON
T
A
= -40°C
T
A
= +25°C
16
14
OUTPUT POWER (dBm)
12
10
T
A
= +85°C
8
T
A
= +125°C
6
4
T
A
= -40°C
3.6
2.1
2.4
2.7
3.0
3.3
3.6
2.1
2.4
2.7
3.0
3.3
3.6
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX1479 toc12
PHASE NOISE vs. OFFSET FREQUENCY
-50
-60
PHASE NOISE (dBc/Hz)
-70
-80
-90
-100
-110
-120
-130
f
RF
= 433MHz
f
RF
= 315MHz
MAX1479 toc13
16
14
OUTPUT POWER (dBm)
12
10
8
T
A
= +125°C
6
4
2.1
2.4
2.7
3.0
3.3
f
RF
= 433MHz
PA ON
ENVELOPE SHAPING
DISABLED
T
A
= +25°C
T
A
= -40°C
-40
T
A
= +85°C
-140
3.6
100
1k
10k
100k
1M
10M
SUPPLY VOLTAGE (V)
OFFSET FREQUENCY (Hz)
CLOCK SPUR MAGNITUDE
vs. SUPPLY VOLTAGE
f
RF
= 315MHz
CLKOUT SPUR = f
RF
±
f
CLKOUT
10pF LOAD CAPACITANCE
f
CLKOUT
= f
XTAL
/16
MAX1479 toc14
FREQUENCY STABILITY
vs. SUPPLY VOLTAGE
8
FREQUENCY STABILITY (ppm)
6
4
2
0
-2
-4
-6
-8
f
RF
= 433MHz
f
RF
= 315MHz
MAX1479 toc15
-40
CLKOUT SPUR MAGNITUDE (dBc)
-45
-50
-55
-60
-65
-70
2.1
2.4
2.7
3.0
3.3
f
CLKOUT
= f
XTAL
/4
10
f
CLKOUT
= f
XTAL
/8
-10
3.6
2.1
2.4
2.7
3.0
3.3
3.6
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
5
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