MAXIM MAX1473 Technical data

General Description

The MAX1473 fully integrated low-power CMOS super­heterodyne receiver is ideal for receiving amplitude­shift-keyed (ASK) data in the 300MHz to 450MHz
frequency range. Its signal range is from -114dBm to
0dBm. With few external components and a low-current
power-down mode, it is ideal for cost- and power-sensi­tive applications typical in the automotive and consumer
markets. The chip consists of a low-noise amplifier
(LNA), a fully differential image-rejection mixer, an on­chip phase-locked-loop (PLL) with integrated voltage­controlled oscillator (VCO), a 10.7MHz IF limiting
amplifier stage with received-signal-strength indicator
(RSSI), and analog baseband data-recovery circuitry.
The MAX1473 also has a discrete one-step automatic
gain control (AGC) that drops the LNA gain by 35dB
when the RF input signal is greater than -57dBm.

The MAX1473 is available in 28-pin TSSOP and 32-pin
thin QFN packages. Both versions are specified for the
extended (-40°C to +85°C) temperature range.

Applications

Automotive Remote Keyless Entry Security Systems

Garage Door Openers Home Automation

Remote Controls Local Telemetry

Wireless Sensors

Systems

Features

o Optimized for 315MHz or 433MHz ISM Band

o Operates from Single 3.3V or 5.0V Supplies

o High Dynamic Range with On-Chip AGC

o Selectable Image-Rejection Center Frequency

o Selectable x64 or x32 fLO/f

XTAL

Ratio

o Low 5.2mA Operating Supply Current

o < 2.5µA Low-Current Power-Down Mode for

Efficient Power Cycling

o 250µs Startup Time

o Built-In 50dB RF Image Rejection

o Receive Sensitivity of -114dBm

MAX1473

315MHz/433MHz ASK Superheterodyne

Receiver with Extended Dynamic Range

________________________________________________________________

Maxim Integrated Products

1

Pin Configurations

Ordering Information

19-2748; Rev 6; 1/12

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.

Functional Diagram and Typical Application Circuit appear
at end of data sheet.

EVALUATION KIT

AVAILABLE

+

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

*

EP = Exposed pad.

PART TEMP RANGE PIN-PACKAGE

MAX1473EUI+ -40°C to +85°C 28 TSSOP
MAX1473ETJ+ -40°C to +85°C 32 Thin QFN-EP*

TOP VIEW

XTAL1

AVDD

LNAIN

LNASRC

AGND

LNAOUT

AVDD

MIXIN1

MIXIN2

AGND

IRSEL

MIXOUT

DGND

DVDD

+

1

2

3

4

5

MAX1473

6

7

8

9

10

11

12

13

14

TSSOP

28

27

26

25

24

23

22

21

20

19

18

17

16

15

XTAL2

PWRDN

PDOUT

DATAOUT

V

DD5

DSP

DFFB

OPP

DSN

DFO

IFIN2

IFIN1

XTALSEL

AGCDIS

AGND

LNAOUT

AVDD

MIXIN1

MIXIN2

AGND

IRSEL

AVDD

XTAL1

30

29

MAX1473

11

12

DVDD

AGCDIS

XTAL2

28

13

N.C.

LNASRC

LNAIN

32

9

MIXOUT

31

10

DGND

+

1N.C.

2

3

4

5

6

7

8

THIN QFN

PWRDN

PDOUT

25 N.C.

27

26

24 DATAOUT

23

V

DD5

22

DSP

21

N.C.

20

DFFB

19

OPP

18

DSN

17

DFO

16IFIN2

14

15

IFIN1

XTALSEL

MAX1473

315MHz/433MHz ASK Superheterodyne
Receiver with Extended Dynamic Range

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS (3.3V OPERATION)

(

Typical Application Circuit

, VDD= 3.0V to 3.6V, no RF signal applied, TA= -40°C to +85°C, unless otherwise noted. Typical values

are at V

DD

= 3.3V and TA= +25°C.) (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.

V

DD5

to AGND.......................................................-0.3V to +6.0V

AVDD to AGND .....................................................-0.3V to +4.0V

DVDD to DGND .....................................................-0.3V to +4.0V

AGND to DGND.....................................................-0.1V to +0.1V

IRSEL, DATAOUT, XTALSEL, AGCDIS,

PWRDN to AGND .....................................-0.3V to (V

DD5

+ 0.3V)

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

DD

+ 0.3V)

Continuous Power Dissipation (T

A

= +70°C)

28-Pin TSSOP (derate 12.8mW/°C above +70°C) .1025.6mW
32-Pin Thin QFN (derate 21.3mW/°C

above +70°C).........................................................1702.1mW

Operating Temperature Ranges

MAX1473E__ ..................................................-40°C to +85°C

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

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

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

Supply Voltage V

Supply Current I

Shutdown Supply Current I

Input Voltage Low V

Input Voltage High V

Input Logic Current High I

DATAOUT Voltage Output Low V

DATAOUT Voltage Output High V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DD

DD

PWRDN

IH

OL

OH

3.3V nominal supply 3.0 3.3 3.6 V

fRF = 315MHz 5.2 6.23

DD

fRF = 433MHz 5.8 6.88

fRF = 315MHz 1.6

f

= 433MHz 2.5 5.3

RF

VDD - 0.4 V

= V

IRSEL

IRSEL

IRSEL

DD

= VDD/2 1.1 VDD - 1.5Image Reject Select (Note 2)

= 0V 0.4

V

DD

- 0.4 V

IL

IH

V

V
V

fRF = 433MHz, V

fRF = 375MHz, V

f

RL = 5kΩ

= V

P WRDN

= 0V,

P WRDN

= 0V

XTALSEL

= 315MHz, V

RF

0.4 V

10 µA

VDD - 0.4

0.4 V

mA

µA

V

MAX1473

315MHz/433MHz ASK Superheterodyne

Receiver with Extended Dynamic Range

_______________________________________________________________________________________ 3

DC ELECTRICAL CHARACTERISTICS (5.0V OPERATION)

(

Typical Application Circuit

, VDD= 4.5V to 5.5V, no RF signal applied, TA= -40°C to +85°C, unless otherwise noted. Typical values

are at V

DD

= 5.0V and TA= +25°C.) (Note 1)

AC ELECTRICAL CHARACTERISTICS

(

Typical Application Circuit

, VDD= 3.0V to 3.6V, all RF inputs are referenced to 50Ω, fRF= 315MHz, TA= -40°C to +85°C, unless

otherwise noted. Typical values are at V

DD

= 3.3V and TA= +25°C.) (Note 1).

Supply Voltage V

Supply Current I

Shutdown Supply Current I

Input Voltage Low V

Input Voltage High V

Input Logic Current High I

DATAOUT Voltage Output Low V

DATAOUT Voltage Output High V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DD

DD

PWRDN

IH

OL

OH

5.0V nominal supply 4.5 5.0 5.5 V

fRF = 315MHz 5.2 6.04

DD

fRF = 433MHz 5.7 6.76

fRF = 315MHz 2.3

f

= 433MHz 2.8 6.2

RF

VDD - 0.4 V

= V

IRSEL

IRSEL

IRSEL

DD

= VDD/2 1.1 VDD - 1.5Image Reject Select (Note 2)

= 0V 0.4

VDD - 0.4

- 0.4 V

V

DD

10 µA

IL

IH

V

V
V

fRF = 433MHz, V

fRF = 375MHz, V

f

RL = 5kΩ

= V

P WRDN

= 0V,

P WRDN

XTALSEL

RF

= 0V

= 315MHz, V

0.4 V

0.4 V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

GENERAL CHARACTERISTICS

Startup Time t

Receiver Input Frequency f

Maximum Receiver Input Level P

Sensitivity (Note 3) P

AGC Hysteresis LNA gain from low to high

LNA IN HIGH-GAIN MODE

Power Gain 16 dB

1dB Compression Point P1dB

Input-Referred 3rd-Order
Intercept

ON

RF

RFIN_MAX

RFIN_MIN

IN_LNA

IIP3

Time for valid signal detection after

P WRDN

= V

OH

V

Modulation depth > 18dB 0 dBm

Peak power level -114 dBm

Normalized to
50Ω

LNA

LNA

250 µs

300 450 MHz

8dB

150 ms

fRF = 433MHz 1 - j3.4

fRF = 375MHz 1 - j3.9Input Impedance (Note 4) Z

= 315MHz 1 - j4.7

f

RF

-22 dBm

-12 dBm

mA

µA

V

MAX1473

315MHz/433MHz ASK Superheterodyne
Receiver with Extended Dynamic Range

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS (continued)

(

Typical Application Circuit

, VDD= 3.0V to 3.6V, all RF inputs are referenced to 50Ω, fRF= 315MHz, TA= -40°C to +85°C, unless

otherwise noted. Typical values are at V

DD

= 3.3V and TA= +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

LO Signal Feedthrough to
Antenna

Noise Figure NF

LNA IN LOW-GAIN MODE

1dB Compression Point P1dB

Input-Referred 3rd-Order
Intercept

LO Signal Feedthrough to
Antenna

Noise Figure NF

Power Gain 0dB

Voltage Gain Reduction AGC enabled (depends on tank Q) 35 dB

MIXER

Input-Referred 3rd-Order
Intercept

Output Impedance Z

Noise Figure NF

Image Rejection
(not Including LNA Tank)

Conversion Gain 330Ω IF filter load 13 dB

INTERMEDIATE FREQUENCY (IF)

Input Impedance Z

Operating Frequency f

3dB Bandwidth 20 MHz
RSSI Linearity ±0.5 dB

RSSI Dynamic Range 80 dB

RSSI Level

RSSI Gain 14.2 mV/dB

AGC Threshold

LNA

IN_LNA

IIP3

LNA

IIP3

OUT_MIX

IN_IF

IF

Normalized to
50Ω

LNA

LNA

MIX

MIX

fRF = 433MHz, V

fRF = 375MHz, V

= 315MHz, V

f

RF

Bandpass response 10.7 MHz

P

< -120dBm 1.15

RFIN

> 0dBm, AGC enabled 2.35

P

RFIN

LNA gain from low to high 1.45

LNA gain from high to low 2.05

fRF = 433MHz 1 - j3.4

fRF = 375MHz 1 - j3.9Input Impedance (Note 4) Z

= 315MHz 1 - j4.7

f

RF

= V

IRSEL

IRSEL

IRSEL

DD

= VDD/2 44

= 0V 44

-80 dBm

2dB

-10 dBm

-7 dBm

-80 dBm

2dB

-18 dBm

330 Ω

16 dB

42

dB

330 Ω

V

V

MAX1473

315MHz/433MHz ASK Superheterodyne

Receiver with Extended Dynamic Range

_______________________________________________________________________________________ 5

Note 1: 100% tested at TA= +25°C. Guaranteed by design and characterization over temperature.

Note 2: IRSEL is internally set to 375MHz IR mode. It can be left open when the 375MHz image rejection setting is desired. A 1nF

capacitor is recommended in noisy environments.

Note 3: BER = 2 x 10

-3

, Manchester encoded, data rate = 4kbps, IF bandwidth = 280kHz.

Note 4: Input impedance is measured at the LNAIN pin. Note that the impedance includes the 15nH inductive degeneration con-

nected from the LNA source to ground. The equivalent input circuit is 50Ω in series with 2.2pF.

Note 5: Crystal oscillator frequency for other RF carrier frequency within the 300MHz to 450MHz range is (f

RF

- 10.7MHz)/64 for

XTALSEL = 0V, and (f

RF

- 10.7MHz)/32 for XTALSEL = VDD.

AC ELECTRICAL CHARACTERISTICS (continued)

(

Typical Application Circuit

, VDD= 3.0V to 3.6V, all RF inputs are referenced to 50Ω, fRF= 315MHz, TA= -40°C to +85°C, unless

otherwise noted. Typical values are at V

DD

= 3.3V and TA= +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DATA FILTER

Maximum Bandwidth BW

DATA SLICER

Comparator Bandwidth BW

Output High Voltage V

Output Low Voltage 0V

CRYSTAL OSCILLATOR

Crystal Frequency (Note 5) f

Crystal Tolerance 50 ppm

Input Capacitance From each pin to ground 6.2 pF

Recommended Crystal Load
Capacitance

Maximum Crystal Load
Capacitance

DF

CMP

fRF = 433MHz

XTAL

fRF = 315MHz

C

LOAD

C

LOAD

V

XTALSEL

V

XTALSEL

V

XTALSEL

V

XTALSEL

100 kHz

100 kHz

DD5

= 0V 6.6128

= V

DD

= 0V 4.7547

= V

DD

13.2256

9.5094

3pF

10 pF

V

MHz

MHz