MAXIM MAX1472 Technical data

General Description

The MAX1472 is a crystal-referenced phase-locked
loop (PLL) VHF/UHF transmitter designed to transmit
OOK/ASK data in the 300MHz to 450MHz frequency
range. The MAX1472 supports data rates up to
100kbps, and adjustable output power to more than
+10dBm into a 50Ω load. The crystal-based architec­ture of the MAX1472 eliminates many of the common
problems with SAW transmitters by providing greater
modulation depth, faster frequency settling, higher
tolerance of the transmit frequency, and reduced
temperature dependence. Combined, these improve­ments enable better overall receiver performance when
using a superheterodyne receiver such as the MAX1470
or MAX1473.

The MAX1472 is available in a 3mm x 3mm 8-pin
SOT23 package and is specified for the automotive
(-40°C to +125°C) temperature range. An evaluation kit
is available. Contact Maxim Integrated Products for
more information.

Applications

Remote Keyless Entry

RF Remote Controls

Tire Pressure Monitoring

Security Systems

Radio-Controlled Toys

Wireless Game Consoles

Wireless Computer Peripherals

Wireless Sensors

Features

o 2.1V to 3.6V Single-Supply Operation

o Low 5.3mA Operating Supply Current*

o Supports ASK with 90dB Modulation Depth

o Output Power Adjustable to More than +10dBm

o Uses Small Low-Cost Crystal

o Small 3mm

 3mm 8-Pin SOT23 Package

o Fast-On Oscillator 220µs Startup Time

MAX1472

300MHz-to-450MHz Low-Power,

Crystal-Based ASK Transmitter

________________________________________________________________

Maxim Integrated Products

1

Pin Configuration

Ordering Information

8

7

6

5

1

+

2

3

4

DATA

ENABLE

PAOUT

XTAL2

V

DD

GND

PAGND

XTAL1

MAX1472

3.0V

DATA INPUT

STANDBY OR

POWER-UP

*

680pF220pF

50Ω

ANTENNA

Typical Application Circuit

19-2872; Rev 3; 10/10

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.

EVALUATION KIT

AVAILABLE

*

Optional power adjust resistor.

+

Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

*

At 50% duty cycle (315MHz, 2.7V supply, +10dBm output

power)

PART

MAX1472AKA+T -40°C to +125°C 8 SOT23 AEKS

TEMP

RANGE

PIN­PACKAGE

TOP

MARK

TOP VIEW

1

XTAL1

2

GND

3

PAGND

4

+

87XTAL2

V

MAX1472

SOT23

DD

DATA

6

ENABLEPAOUT

5

MAX1472

300MHz-to-450MHz Low-Power,
Crystal-Based ASK Transmitter

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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 +4.0V

All Other Pins to GND ................................-0.3V to (V

DD

+ 0.3V)

Continuous Power Dissipation (T

A

= +70°C)

8-Pin SOT23 (derate 8.9mW/°C above +70°C)............714mW

Operating Temperature Range .........................-40°C to +125°C

Storage Temperature Range .............................-60°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Soldering Temperature (reflow) .......................................+260°C

ELECTRICAL CHARACTERISTICS

(

Typical Application Circuit

, output power is 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)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SYSTEM PERFORMANCE

Supply Voltage V

Supply Current I

Standby Current I

Frequency Range f

Data Rate (Note 3) 0 100 kbps

Modulation Depth ON to OFF P

Output Power P

Turn-On Time t

Transmit Efficiency with CW

Transmit Efficiency at 50%
Duty Cycle

DD

V

ENABLE

= V

DD

(Note 2)

DD

V
V

V
V

V

ENABLE

= V

DATA

ENABLE

= 0V

DATA

ENABLE

= VDD,

DD

= VDD,

= V

DD

(Note 2)

STDBY

RF

fRF = 433MHz

V
V

V
V

V

V

< VIL, TA < +85°C (Note 3) 5 350 nA

ENABLE

< V

ENABLE

TA < +125°C (Note 3) 1.7 µA

IL

(Note 1) 300 450 MHz

ratio (Note 4) 90 dB

OUT

ENABLE

= V

DATA

ENABLE

= 0V

DATA

= VDD,

DD

= VDD,

TA = +25°C, VDD = 2.7V (Notes 5, 6) 7.3 10.3 12.8

OUT

TA = + 125° C , V

= 2.1V ( N otes 5, 6) 3.3 6.0

D D

TA = -40°C, VDD = 3.6V (Notes 5, 6) 13.7 16.2

ON

To f

To f

f

RF

f

RF

f

RF

f

RF

< 50kHz (Note 7) 220

OFFSET

< 5kHz (Note 7) 450

OFFSET

= 315MHz (Note 8) 43.6

= 433MHz (Note 8) 41.3

= 315MHz (Note 9) 37.6

= 433MHz (Note 9) 35.1

2.1 3.6 V

5.3 9.4

9.1 16.6fRF = 315MHz

1.5 2.3

5.7

9.6

1.7 2.7

mA

dBm

µs

%

%

MAX1472

300MHz-to-450MHz Low-Power,

Crystal-Based ASK Transmitter

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(

Typical Application Circuit

, output power is 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)

Note 1: 100% tested at TA= +25°C. Guaranteed by design and characterization over temperature.
Note 2: 50% duty cycle at 10kHz data.
Note 3: Guaranteed by design and characterization, not production tested.
Note 4: Generally limited by PC board layout.
Note 5: Output power can be adjusted with external resistor.
Note 6: Guaranteed by design and characterization at f

RF

= 315MHz.

Note 7: V

ENABLE

< VILto V

ENABLE

> VIH. f

OFFSET

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

Note 8: V

ENABLE

> VIH, V

DATA

> VIH, Efficiency = P

OUT

/(VDDx IDD).

Note 9: V

ENABLE

> VIH, DATA toggled from VILto VIH, 10kHz, 50% duty cycle, Efficiency = P

OUT

/(VDDx IDD).

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

PHASE-LOCKED LOOP PERFORMANCE

VCO Gain 330 MHz/V

=100kHz -84

f

OFFSET

f

= 1MHz -91

OFFSET

f

=100kHz -82

OFFSET

= 1MHz -89

f

OFFSET

dBc/Hz

dBc

dBc

Phase Noise

Maximum Carrier Harmonics

Reference Spur

= 315MHz

f

RF

f

= 433MHz

RF

f

= 315MHz -50

RF

= 433MHz -50

f

RF

f

= 315MHz -75

RF

= 433MHz -81

f

RF

Loop Bandwidth 1.6 MHz

Crystal Frequency f

XTAL

/ 32 MHz

f

RF

Oscillator Input Impedance From each XTAL pin to GND 6.2 pF

Frequency Pushing by V

DD

3 ppm/V

DIGITAL INPUTS

Data Input High V

Data Input Low V

IH

IL

V

- 0.25 V

D D

0.25 V

Maximum Input Current 2nA

Pulldown Current 25 µA