MAX7044AKA+T - Maxim - Pdf.Support

General Description

The MAX7044 crystal-referenced phase-locked-loop

(PLL) VHF/UHF transmitter is designed to transmit

OOK/ASK data in the 300MHz to 450MHz frequency

range. The MAX7044 supports data rates up to 100kbps,

and provides output power up to +13dBm into a 50Ω

load while only drawing 7.7mA at 2.7V.

The crystal-based architecture of the MAX7044 elimi-

nates many of the common problems with SAW-based

transmitters by providing greater modulation depth,

faster frequency settling, higher tolerance of the trans-

mit frequency, and reduced temperature dependence.

The MAX7044 also features a low supply voltage of

+2.1V to +3.6V. These improvements enable better

overall receiver performance when using the MAX7044

together with a superheterodyne receiver such as the

MAX1470 or MAX1473.

A simple, single-input data interface and a buffered

clock-out signal at 1/16th the crystal frequency make

the MAX7044 compatible with almost any microcon-

troller or code-hopping generator.

The MAX7044 is available in an 8-pin SOT23 package

and is specified over the -40°C to +125°C automotive

temperature range.

Applications

Remote Keyless Entry (RKE)

Tire-Pressure Monitoring (TPM)

Security Systems

Garage Door Openers

RF Remote Controls

Wireless Game Consoles

Wireless Computer Peripherals

Wireless Sensors

Features

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

oOOK/ASK Transmit Data Format

oUp to 100kbps Data Rate

o+13dBm Output Power into 50Ω Load

oLow 7.7mA (typ) Operating Supply Current*

oUses Small, Low-Cost Crystal

oSmall 3mm x 3mm 8-Pin SOT23 Package

oFast-On Oscillator: 250μs Startup Time

* At 50% duty cycle (315MHz, 2.7V supply, +13dBm output

power)

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

________________________________________________________________

Maxim Integrated Products

DATA

CLKOUTPAOUT

XTAL2

VDD

GND

PAGND

XTAL1

SOT23

TOP VIEW

MAX7044

Pin Configuration

Ordering Information

MAX7044

1XTAL1

ANTENNA

3.0V 3.0V

680pF

220pF

100nF 100nF

XTAL2

fXTAL

2GND VDD

3PAGND DATA INPUT

CLOCK

OUTPUT

(fCLKOUT =

fXTAL/16)

DATA 6

4PAOUT CLKOUT 5

Typical Application Circuit

19-3221; Rev 4; 2/11

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

PART TEMP RANGE PIN-

PACKAGE TOP MARK

MAX7044AKA+T -40°C to +125°C 8 SOT23 AEJW

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

T = Tape and reel.

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(

Typical Application Circuit

, all RF inputs and outputs are referenced to 50Ω, VDD = +2.1V to +3.6V, TA= -40°C to +125°C, unless

otherwise noted. Typical values are at VDD = +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.

VDD to GND ..........................................................-0.3V to +4.0V

All Other Pins to GND ................................-0.3V to (VDD + 0.3V)

Continuous Power Dissipation (TA= +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

Junction Temperature......................................................+150°C

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

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SYSTEM PERFORMANCE

Supply Voltage VDD 2.1 3.6 V

VDATA at 50% duty

cycle, (Notes 3, 4) 7.7 14.1

PA on (Note 5) 13.8 25.4

fRF = 315MHz

PA off (Note 6) 1.7 2.8

VDATA at 50% duty

cycle, (Notes 3, 4) 8.0 14.4

PA on (Note 5) 14.0 25.7

Supply Current

(Note 2) IDD

fRF = 433MHz

PA off (Note 6) 1.9 3.1

TA < +25°C 40 130

Standby Current ISTDBY

VDATA < VIL for

more than WAIT

time (Notes 4, 7) TA < +125°C 550 2900 nA

Frequency Range (Note 4) fRF 300 450 MHz

Data Rate (Note 4) 0 100 kbps

Modulation Depth (Note 8) ON to OFF POUT ratio 90 dB

TA = +25°C, VDD =

+2.7V 9.6 12.5 15.4

TA = +125°C, VDD =

+2.1V 5.9 9.0 12.0

Output Power, PA On

(Notes 4, 5) POUT fRF = 300MHz to

450MHz

TA = -40°C, VDD =

+3.6V 13.1 15.8 18.5

dBm

Oscillator settled to within 50kHz 220

Turn-On Time tON Oscillator settled to within 5kHz 450 µs

fRF = 315MHz 48

Transmit Efficiency with CW

(Notes 5, 9) fRF = 433MHz 47 %

fRF = 315MHz 43

Transmit Efficiency with 50%

OOK (Notes 3, 9) fRF = 433MHz 41 %

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(

Typical Application Circuit

, all RF inputs and outputs are referenced to 50Ω, VDD = +2.1V to +3.6V, TA= -40°C to +125°C, unless

otherwise noted. Typical values are at VDD = +2.7V, TA= +25°C, unless otherwise noted.) (Note 1)

Note 1: Supply current, output power, and efficiency are greatly dependent on board layout and PAOUT match.

Note 2: Production tested at TA= +25°C with fRF = 300MHz and 450MHz. Guaranteed by design and characterization over tem-

perature and frequency.

Note 3: 50% duty cycle at 10kbps with Manchester coding.

Note 4: Guaranteed by design and characterization, not production tested.

Note 5: PA output is turned on in test mode by VDATA = VDD/2 + 100mV.

Note 6: PA output is turned off in test mode by VDATA = VDD/2 – 100mV.

Note 7: Wait time: tWAIT = (216 x 32)/fRF.

Note 8: Generally limited by PCB layout.

Note 9: VDATA = VIH. Efficiency = POUT/(VDD x IDD).

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

PHASE-LOCKED LOOP (PLL)

VCO Gain 330 MHz/V

fOFFSET = 100kHz -84

fRF = 315MHz fOFFSET = 1MHz -91

fOFFSET = 100kHz -82

Phase Noise

fRF = 433MHz fOFFSET = 1MHz -89

dBc/Hz

fRF = 315MHz -50

Maximum Carrier Harmonics fRF = 433MHz -50 dBc

fRF = 315MHz -74

Reference Spur fRF = 433MHz -80 dBc

Loop Bandwidth 1.6 MHz

Crystal Frequency fXTAL fRF/32 MHz

Frequency Pulling by VDD 3 ppm/V

Crystal Load Capacitance 3pF

DATA INPUT

Data Input High VIH VDD -

0.25 V

Data Input Low VIL 0.25 V

Maximum Input Current 10 µA

Pulldown Current 10 µA

CLKOUT OUTPUT

Output Voltage Low VOL ISINK = 650µA (Note 4) 0.25 V

Output Voltage High VOH ISOURCE = 350µA (Note 4) VDD -

0.25 V

Load Capacitance CLOAD (Note 4) 10 pF

CLKOUT Frequency fXTAL/16 Hz

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

4 _______________________________________________________________________________________

Typical Operating Characteristics

(

Typical Application Circuit

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

2.1 2.4 2.7 3.0 3.3 3.6

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX7044 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

fRF = 315MHz

PA ON

TA = -40°C

TA = +25°C

TA = +85°C

TA = +125°C

2.1 2.4 2.7 3.0 3.3 3.6

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX7044 toc02

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

TA = +25°C

fRF = 315MHz

PA 50% DUTY CYCLE AT 10kHz

TA = -40°C

TA = +85°C

TA = +125°C

2.1 2.72.4 3.0 3.3 3.6

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX7044 toc03

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

TA = +25°C

fRF = 433MHz

PA ON

TA = -40°C

TA = +85°C

TA = +125°C

2.1 2.4 2.7 3.0 3.3 3.6

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX7044 toc04

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

TA = +25°C

fRF = 433MHz

PA 50% DUTY CYCLE AT 10kHz

TA = -40°C

TA = +85°C

TA = +125°C

2.1 2.72.4 3.0 3.3 3.6

OUTPUT POWER

vs. SUPPLY VOLTAGE

MAX7044 toc05

SUPPLY VOLTAGE (V)

OUTPUT POWER (dBm)

fRF = 315MHz

PA ON

TA = +25°C

TA = -40°C

TA = +85°C

TA = +125°C

2.1 2.72.4 3.0 3.3 3.6

OUTPUT POWER

vs. SUPPLY VOLTAGE

MAX7044 toc06

SUPPLY VOLTAGE (V)

OUTPUT POWER (dBm)

fRF = 433MHz

PA ON

TA = +25°C

TA = -40°C

TA = +85°C

TA = +125°C

-80

-78

-74

-76

-72

-70

2.1 2.72.4 3.0 3.3 3.6

REFERENCE SPUR MAGNITUDE

vs. SUPPLY VOLTAGE

MAX7044 toc07

SUPPLY VOLTAGE (V)

REFERENCE SPUR MAGNITUDE (dBc)

REFERENCE SPUR = fRF ± fXTAL

fRF = 433MHz

fRF = 315MHz

-3

-1

-2

2.1 2.72.4 3.0 3.3 3.6

FREQUENCY STABILITY

vs. SUPPLY VOLTAGE

MAX7044 toc08

SUPPLY VOLTAGE (V)

FREQUENCY STABILITY (ppm)

fRF = 433MHz

fRF = 315MHz

2.1 2.4 2.7 3.0 3.3 3.6

TRANSMIT POWER EFFICIENCY

vs. SUPPLY VOLTAGE

MAX7044 toc09

SUPPLY VOLTAGE (V)

TRANSMIT POWER EFFICIENCY (%)

fRF = 315MHz

PA ON

TA = -40°C

TA = +85°C

TA = +125°C

TA = +25°C

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

_______________________________________________________________________________________

2.1 2.4 2.7 3.0 3.3 3.6

TRANSMIT POWER EFFICIENCY

vs. SUPPLY VOLTAGE

MAX7044 toc10

SUPPLY VOLTAGE (V)

TRANSMIT POWER EFFICIENCY (%)

fRF = 315MHz

PA 50% DUTY CYCLE AT 10kHz

TA = -40°C

TA = +85°C

TA = +125°C

TA = +25°C

2.1 2.4 2.7 3.0 3.3 3.6

TRANSMIT POWER EFFICIENCY

vs. SUPPLY VOLTAGE

MAX7044 toc11

SUPPLY VOLTAGE (V)

TRANSMIT POWER EFFICIENCY (%)

fRF = 433MHz

PA ON TA = -40°C

TA = +85°C

TA = +125°C

TA = +25°C

2.1 2.72.4 3.0 3.3 3.6

TRANSMIT POWER EFFICIENCY

vs. SUPPLY VOLTAGE

MAX7044 toc12

SUPPLY VOLTAGE (V)

TRANSMIT POWER EFFICIENCY (%)

fRF = 433MHz

PA 50% DUTY CYCLE AT 10kHz TA = +25°C

TA = -40°C

TA = +85°C

TA = +125°C

-140

-110

-120

-130

-100

-90

-80

-70

-60

-50

-40

0.01 10.1 10 100 1 10

PHASE NOISE vs. OFFSET FREQUENCY

MAX7044 toc13

OFFSET FREQUENCY (kHz)

PHASE NOISE (dBc/Hz)

0 1 10 100 1000 10,000

SUPPLY CURRENT AND OUTPUT POWER

vs. EXTERNAL RESISTOR

MAX7044 toc14

EXTERNAL RESISTOR (Ω)

SUPPLY CURRENT (mA)

-16

-12

-8

-4

POWER

CURRENT

fRF = 315MHz

PA ON

OUTPUT POWER (dBm)

-10 -2 2-6 6 10 14

SUPPLY CURRENT vs. OUTPUT POWER

MAX7044 toc15

OUTPUT POWER (dBm)

SUPPLY CURRENT (mA)

fRF = 315MHz

PA ON

50% DUTY CYCLE

50kHz/

div

25μs/div

FREQUENCY SETTLING TIME

MAX7044 toc16

AM DEMODULATION OF PA OUTPUT

DATA RATE = 100kHz

MAX7044 toc17

5dB/

div

3.2μs/div

OUTPUT SPECTRUM

MAX7044 toc18

10dB/

div

0dB

100MHz/div

fRF = 315MHz

Typical Operating Characteristics (continued)

(

Typical Application Circuit

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

Detailed Description

The MAX7044 is a highly integrated ASK transmitter

operating over the 300MHz to 450MHz frequency

band. The IC requires only a few external components

to complete a transmit solution. The MAX7044 includes

a complete PLL and a highly efficient power amplifier.

The device is automatically placed into a low-power

shutdown mode and powers up when data is detected

on the data input.

Shutdown Mode

The MAX7044 has an automatic shutdown mode that

places the device in low-power mode if the DATA input

has not toggled for a specific amount of time (wait time).

The wait time is equal to 216 clock cycles of the crystal.

This equates to a wait time of approximately 6.66ms for

a 315MHz RF frequency and 4.84ms for a 433MHz RF

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

6 _______________________________________________________________________________________

Pin Description

PIN NAME FUNCTION

1 XTAL1 1st Crystal Input. fXTAL = fRF/32.

2 GND Ground. Connect to system ground.

3 PAGND Ground for the Power Amplifier (PA). Connect to system ground.

4 PAOUT Power-Amplifier Output. The PA output requires a pullup inductor to the supply voltage, which can be

part of the output-matching network to an antenna.

CLKOUT

Buffered Clock Output. The frequency of CLKOUT is fXTAL/16.

6 DATA OOK Data Input. DATA also controls the power-up state (see the Shutdown Mode section).

DD Supply Voltage. Bypass to GND with a 100nF capacitor as close to the pin as possible.

8 XTAL2 2nd Crystal Input. fXTAL = fRF/32.

MAX7044

CLKOUT

PAGND

PAOUT

GND

DATA

XTAL1 /16

DATA

ACTIVITY

DETECTOR

LOCK DETECT 32x PLL

CRYSTAL-

OSCILLATOR

DRIVER

XTAL2

VDD

Functional Diagram

-55

-52

-46

-49

-43

-40

2.1 2.72.4 3.0 3.3 3.6

CLKOUT SPUR MAGNITUDE

vs. SUPPLY VOLTAGE

MAX7044 toc19

SUPPLY VOLTAGE (V)

CLKOUT SPUR MAGNITUDE (dBc)

fRF = 315MHz

Typical Operating Characteristics (continued)

(

Typical Application Circuit

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

frequency. For other frequencies, calculate the wait

time with the following equation:

where tWAIT is the wait time to shutdown and fRF is the

RF transmit frequency.

When the device is in shutdown, a rising edge on DATA

initiates the warm up of the crystal and PLL. The crystal

and PLL must have 220µs settling time before data can

be transmitted. The 220µs turn-on time of the MAX7044

is dominated by the crystal oscillator startup time. Once

the oscillator is running, the 1.6MHz PLL loop band-

width allows fast frequency recovery during power

amplifier toggling.

When the device is operating, each edge on the data

line resets an internal counter to zero and it begins to

count again. If no edges are detected on the data line,

the counter reaches the end-of-count (216 clock cycles)

and places the device in shutdown mode. If there is an

edge on the data line before the counter hits the end of

count, the counter is reset and the process starts over.

It may be necessary to keep the power amplifier on

steadily for testing and debugging purposes. To do

this, set the DATA pin voltage slightly above the mid-

point between VDD and ground (VDD/2 + 100mV).

Phase-Locked Loop

The PLL block contains a phase detector, charge

pump, integrated loop filter, VCO, asynchronous 32x

clock divider, and crystal oscillator. This PLL requires

no external components. The relationship between the

carrier and crystal frequency is given by:

fXTAL = fRF/32

The lock-detect circuit prevents the power amplifier

from transmitting until the PLL is locked. In addition, the

device shuts down the power amplifier if the reference

frequency is lost.

Power Amplifier (PA)

The PA of the MAX7044 is a high-efficiency, open-

drain, switch-mode amplifier. With a proper output

matching network, the PA can drive a wide range of

impedances, including the small-loop PCB trace anten-

na and any 50Ωantenna. The output-matching network

for an antenna with a characteristic impedance of 50Ω

is shown in the

Typical Application Circuit

. The output-

matching network suppresses the carrier harmonics

and transforms the antenna impedance to an optimal

impedance at PAOUT, which is about 125Ω.

When the output matching network is properly tuned,

the power amplifier transmits power with high efficiency.

The

Typical Application Circuit

delivers +13dBm at

+2.7V supply with 7.7mA of supply current. Thus, the

overall efficiency is 48% with the efficiency of the power

amplifier itself greater than 54%.

Buffered Clock Output

The MAX7044 provides a buffered clock output

(CLKOUT) for easy interface to a microcontroller or fre-

quency-hopping generator. The frequency of CLKOUT is

1/16 the crystal frequency. For a 315MHz RF transmit fre-

quency, a crystal of 9.84375MHz is used, giving a clock

output of 615.2kHz. For a 433.92MHz RF frequency, a

crystal of 13.56MHz is used for a clock output of

847.5kHz.

The clock output is inactive when the device is in shut-

down mode. The device is placed in shutdown mode by

the internal data activity detector (see the

Shutdown

Mode

section). Once data is detected on the data input,

the clock output is stable after approximately 220µs.

Applications Information

Output Power Adjustment

It is possible to adjust the output power down to -15dBm

with the addition of a resistor (see RPWRADJ in Figure 1).

The addition of the power adjust resistor also reduces

power consumption. See the Supply Current and

Output Power vs. External Resistor and Supply Current

vs. Output Power graphs in the

Typical Operating

Characteristics

section. It is imperative to add both a

low-frequency and a high-frequency decoupling

capacitor as shown in Figure 1.

Crystal Oscillator

The crystal oscillator in the MAX7044 is designed to

present a capacitance of approximately 3pF between

the XTAL1 and XTAL2 pins. If a crystal designed to

WAIT

=232

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

_______________________________________________________________________________________ 7

MAX7044

1XTAL1

ANTENNA

3.0V

680pF

RPWRADJ

220pF

100nF

XTAL2

fXTAL

2GND VDD

3PAGND DATA INPUT

CLOCK

OUTPUT

(fCLKOUT =

fXTAL/16)

DATA 6

4PAOUT CLKOUT 5

Figure 1. Output Power Adjustment Circuit

MAX7044

oscillate with a different load capacitance is used, the

crystal is pulled away from its intended operating fre-

quency, thus introducing an error in the reference fre-

quency. Crystals designed to operate with higher

differential load capacitance always pull the reference

frequency higher. For example, a 9.84375MHz crystal

designed to operate with a 10pF load capacitance

oscillates at 9.84688MHz with the MAX7044, causing

the transmitter to be transmitting at 315.1MHz rather

than 315.0MHz, an error of about 100kHz, or 320ppm.

In actuality, the oscillator pulls every crystal. The crys-

tal’s natural frequency is really below its specified fre-

quency, but when loaded with the specified load

capacitance, the crystal is pulled and oscillates at its

specified frequency. This pulling is already accounted

for in the specification of the load capacitance.

Additional pulling can be calculated if the electrical

parameters of the crystal are known. The frequency

pulling is given by:

where:

fpis the amount the crystal frequency is pulled in ppm.

Cmis the motional capacitance of the crystal.

Ccase (or Co) is the vendor-specified case capacitance

of the crystal.

Cspec is the specified load capacitance.

Cload is the actual load capacitance.

When the crystal is loaded as specified, i.e., Cload =

Cspec, the frequency pulling equals zero.

Output Matching to 50

When matched to a 50Ωsystem, the MAX7044 PA is

capable of delivering up to +13dBm of output power at

VDD = 2.7V. The output of the PA is an open-drain tran-

sistor that requires external impedance matching and

pullup inductance for proper biasing. The pullup induc-

tance from PA to VDD serves three main purposes: it

resonates the capacitance of the PA output, provides

biasing for the PA, and becomes a high-frequency

choke to reduce the RF energy coupling into VDD. The

recommended output-matching network topology is

shown in the

Typical Application Circuit

. The matching

network transforms the 50Ωload to approximately

125Ωat the output of the PA in addition to forming a

bandpass filter that provides attenuation for the higher

order harmonics.

Output Matching to

PCB Loop Antenna

In some applications, the MAX7044 power amplifier

output has to be impedance matched to a small-loop

antenna. The antenna is usually fabricated out of a cop-

per trace on a PCB in a rectangular, circular, or square

pattern. The antenna will have an impedance that con-

sists of a lossy component and a radiative component.

To achieve high radiating efficiency, the radiative com-

ponent should be as high as possible, while minimizing

the lossy component. In addition, the loop antenna will

have an inherent loop inductance associated with it

(assuming the antenna is terminated to ground). For

example, in a typical application, the radiative imped-

ance is less than 0.5Ω, the lossy impedance is less

than 0.7Ω, and the inductance is approximately 50nH

to 100nH.

The objective of the matching network is to match the

power amplifier output to the small-loop antenna. The

matching components thus transform the low radiative

and resistive parts of the antenna into the much higher

value of the PA output. This gives higher efficiency. The

low radiative and lossy components of the small-loop

antenna result in a higher Q matching network than the

50Ωnetwork; thus, the harmonics are lower.

Layout Considerations

A properly designed PCB is an essential part of any

RF/microwave circuit. At the power amplifier output,

use controlled-impedance lines and keep them as short

as possible to minimize losses and radiation. At high

frequencies, trace lengths that are approximately 1/20

the wavelength or longer become antennas. For exam-

ple, a 2in trace at 315MHz can act as an antenna.

Keeping the traces short also reduces parasitic induc-

tance. Generally, 1in of PCB 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. Using a solid ground plane can reduce the par-

asitic inductance from approximately 20nH/in to 7nH/in.

Also, use low-inductance connections to ground on all

GND pins, and place decoupling capacitors close to all

VDD connections.

CCCC

case load case spec

=+−+

⎛

⎝

⎜⎞

⎠

⎟

106

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

8 _______________________________________________________________________________________

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

_______________________________________________________________________________________ 9

Chip Information

PROCESS: CMOS

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maxim-ic.com/packages. Note that a

“+”, “#”, or “-” in the package code indicates RoHS status only.

Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

8 SOT23 K8SN+1 21-0078 90-0176

MAX7044

300MHz to 450MHz High-Efficiency,

Crystal-Based +13dBm ASK Transmitter

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

3 6/09 Changed part number in Ordering Information to lead-free and made a correction

in the Power Amplifier (PA) section 1, 7

4 2/11

Deleted Maximum Crystal Inductance spec and Note 9 from the Electrical

Characteristics table and updated the Absolute Maximum Ratings, Shutdown

Mode, and Crystal Oscillator sections

2, 3, 7, 8

Revision History