Rainbow Electronics MAX1479 User Manual

General Description

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 transmit­ters by providing greater modulation depth, faster fre­quency settling, higher tolerance of the transmit
frequency, and reduced temperature dependence.
These improvements enable better overall receiver per­formance 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 thin QFN pack­age (3mm x 3mm) and is specified for the automotive
temperature 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

Features

♦ ETSI-Compliant EN300 220

♦ +2.1V to +3.6V Single-Supply Operation

♦ Supports ASK, OOK, and FSK Modulations

♦ Adjustable FSK Shift

♦ +10dBm Output Power into 50Ω Load

♦ Low Supply Current (6.7mA in ASK Mode,

and 10.5mA in FSK Mode)

♦ Uses Small Low-Cost Crystal

♦ Small 16-Pin Thin QFN Package

♦ Fast-On Oscillator—200µs Startup Time

♦ Programmable Clock Output

MAX1479

300MHz to 450MHz Low-Power,

Crystal-Based +10dBm ASK/FSK Transmitter

________________________________________________________________ Maxim Integrated Products 1

16 15 14 13

9

10

11

12

CLK0

CLK1

DEV0

DEV1

TOP VIEW

4

3

2

1

ENABLE

EP

DIN

MODE

V

DD

5678

V

DD_

PA

CLKOUT

PAOUT

ROUT

MAX1479

GND

XTAL2

XTAL1

DEV2

THIN QFN

(3mm x 3mm)

Pin Configuration

Ordering Information

MAX1479

ENABLE

DIN

MODE

V

DD

CLKOUT

V

DD_

PA

ROUT

PAOUT

CLK0

CLK1

DEV0

DEV1

DEV2

XTAL1

XTAL2

GND

CRYSTAL

DRIVER

4

3

2

1

5 6 7 8

9

10

11

12

13141516

CLOCK
DIVIDER

DIVIDE

BY 32

LOOP

FILTER

ASK
FSK

PA

ENVELOPE

SHAPING

DEVIATION

PD/CP

VCO

Functional Diagram

19-3353; Rev 0; 8/04

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.

*EP = Exposed paddle.

PART TEMP RANGE PIN-PACKAGE

MAX1479ATE

16 Thin QFN-EP*

Typical Application Circuit appears at end of data sheet.

-40°C to +125°C

MAX1479

300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(Typical Application Circuit, all RF inputs and outputs are referenced to 50Ω, VDD= +2.1V to +3.6V, V

ENABLE

= VDD, TA= -40°C to

+125°C, unless otherwise noted. Typical values are at V

DD

= +2.7V, TA= +25°C, unless otherwise noted.) (Note 1)

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.

VDDto 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 Thin QFN (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

PARAMETER

CONDITIONS

UNITS

Supply Voltage V

DD

2.1 3.6 V

fRF = 315MHz 2.9 4.3

PA off, V

DIN

at
0% duty cycle
(ASK or FSK)
(Note 2)

f

RF

= 433MHz 3.3 4.8

fRF = 315MHz 6.7

V

DIN

at 50% duty
cycle (ASK)
(Notes 3, 4)

f

RF

= 433MHz 7.3

fRF = 315MHz (Note 2)

Supply Current I

DD

V

DIN

at 100%

fRF = 433MHz (Note 4)

mA

TA = +25°C 0.2

TA < +85°C (Note 4)

300

Standby Current I

STDBYVENABLE

< V

IL

TA < +125°C (Note 2)

nA

DIGITAL INPUTS AND OUTPUTS

Data Input High V

IH

(Note 2)

V

DD

­V

Data Input Low V

IL

(Note 2)

V

Maximum Input Current I

IN

20 µA

Output Voltage High V

OH

CLKOUT, load = 10kΩ || 10pF (Note 4)

V

DD

­V

Output Voltage Low V

OL

CLKOUT, load = 10kΩ || 10pF (Note 4)

V

SYMBOL

MIN TYP MAX

10.7

duty cycle (FSK)

0.25

0.25

10.5 17.1

11.4 18.1

120

700 1600

11.4

0.25

0.25

MAX1479

300MHz to 450MHz Low-Power,

Crystal-Based +10dBm ASK/FSK Transmitter

_______________________________________________________________________________________ 3

Note 1: Supply current, output power, and efficiency are greatly dependent on board layout and PAOUT match.
Note 2: 100% tested at T

A

= +125°C. Guaranteed by design and characterization over temperature.

Note 3: 50% duty cycle at 10kHz ASK data (Manchester coded).
Note 4: Guaranteed by design and characterization, not production tested.
Note 5: V

ENABLE

= VILto V

ENABLE

= VIH. f

OFFSET

is defined as the frequency deviation from the desired carrier frequency.

Note 6: Dependent on crystal and PC board trace capacitance.
Note 7: V

ENABLE

> VIH, V

DATA

> VIH, Efficiency = P

OUT

/ (VDDx IDD).

Note 8: Dependent on PC board trace capacitance.

PARAMETER

CONDITIONS

SYSTEM PERFORMANCE

Frequency Range f

RF

(Note 2)

450

Settle to within 50kHz

Turn-On Time (Note 5) t

ON

Settle to within 5kHz

µs

ASK mode (Manchester coded)

Maximum Data Rate (Note 4)

FSK mode (Manchester coded) 20

fRF = 315MHz 55

Maximum FSK Frequency
Deviation

DEV[2:0] = 111
(Note 6)

f

RF

= 433MHz 80

kHz

TA = +25°C, VDD = +2.7V 6.8 10

TA = +125°C, VDD = +2.1V 2.7 5.3Output Power (Note 2) P

OUT

TA = -40°C, VDD = +3.6V

fRF = 315MHz 35

Transmit Efficiency with CW Tone
(Note 7)

f

RF

= 433MHz 34

%

fRF = 315MHz 27

Transmit Efficiency at 50% Duty
Cycle

f

RF

= 433MHz 25

%

PHASE-LOCKED-LOOP PERFORMANCE

VCO Gain K

VCO

f

OFFSET

= 100kHz -75

fRF = 315MHz

f

OFFSET

= 1MHz -98

f

OFFSET

= 100kHz -74

Phase Noise

f

RF

= 433MHz

f

OFFSET

= 1MHz -98

fRF = 315MHz -50

Maximum Carrier Harmonics

f

RF

= 433MHz -45

dBc

Reference Spur -40 dBc

Loop Bandwidth BW

kHz

Crystal Frequency Range f

XTAL

Crystal Tolerance 50

Crystal Load Capacitance C

LOAD

(Note 8) 4.5 pF

Clock Output Frequency

AC ELECTRICAL CHARACTERISTICS

(Typical Application Circuit, all RF inputs and outputs are referenced to 50Ω, VDD= +2.1V to +3.6V, V

ENABLE

= VDD, TA= -40°C to

+125°C, unless otherwise noted. Typical values are at V

DD

= +2.7V, TA= +25°C, unless otherwise noted.) (Note 1)

SYMBOL

D eter m i ned b y C LK0 and C LK1; see Tab l e 1 F

MIN TYP MAX UNITS

300

200

350

100

12.2 16.1

280 MHz/V

300

fRF/32 MHz

/ N MHz

XTAL

MHz

kbps

12.0

dBm

dBc/Hz

ppm

MAX1479

300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter

4 _______________________________________________________________________________________

Typical Operating Characteristics

(Typical Application Circuit, VDD= +2.7V, TA = +25°C, unless otherwise noted.)

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX1479 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

3.33.02.4 2.7

8

9

10

11

13

12

14

15

7

2.1 3.6

fRF = 315MHz
PA ON

TA = -40°C

TA = +25°C

TA = +125°C

TA = +85°C

3.33.02.72.4

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

5.0

2.1 3.6

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX1479 toc02

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

fRF = 315MHz
PA 50% DUTY CYCLE AT 10kHz

TA = -40°C

TA = +25°C

TA = +125°C

TA = +85°C

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX1479 toc03

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

3.33.02.4 2.7

8

9

10

11

13

12

14

15

7

2.1 3.6

fRF = 433MHz
PA ON

TA = -40°C

TA = +25°C

TA = +125°C

TA = +85°C

3.33.02.72.4

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

5.0

2.1 3.6

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX1479 toc04

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

fRF = 433MHz
PA 50% DUTY CYCLE AT 10kHz

TA = -40°C

TA = +25°C

TA = +125°C

TA = +85°C

SUPPLY CURRENT vs. OUTPUT POWER

MAX1479 toc05

AVERAGE OUTPUT POWER (dBm)

SUPPLY CURRENT (mA)

62-2-6-10

3

4

5

6

7

8

9

10

11

12

2

-14 10

fRF = 315MHz

PA ON

50% DUTY CYCLE

SUPPLY CURRENT vs. OUTPUT POWER

MAX1479 toc06

AVERAGE OUTPUT POWER (dBm)

SUPPLY CURRENT (mA)

62-2-6-10

3

4

5

6

7

8

9

10

11

12

2

-14 10

fRF = 433MHz

PA ON

50% DUTY CYCLE

SUPPLY CURRENT AND OUTPUT POWER

vs. EXTERNAL RESISTOR

MAX1479 toc07

EXTERNAL RESISTOR (Ω)

SUPPLY CURRENT (mA)

OUTPUT POWER (dBm)

1k1001 10

4

6

8

10

14

12

16

18

2

-12

-8

-4

0

8

4

12

16

-16

0.1 10k

fRF = 315MHz
PA ON

POWER

CURRENT

SUPPLY CURRENT AND OUTPUT POWER

vs. EXTERNAL RESISTOR

MAX1479 toc08

EXTERNAL RESISTOR (Ω)

SUPPLY CURRENT (mA)

OUTPUT POWER (dBm)

1k1001 10

4

6

8

10

14

12

16

18

2

0.1 10k

fRF = 433MHz
PA ON

POWER

CURRENT

-12

-8

-4

0

8

4

12

16

-16