Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsMAX1470EUI+

General Description

The MAX1470 is a fully integrated low-power CMOS

superheterodyne receiver for use with amplitude-shift-

keyed (ASK) data in the 315MHz band. With few required

external components, and a low-current power-down

mode, it is ideal for cost- and power-sensitive applica-

tions in the consumer markets. The chip consists of a

315MHz low-noise amplifier (LNA), an image rejection

mixer, a fully integrated 315MHz phase-lock-loop (PLL), a

10.7MHz IF limiting amplifier stage with received-signal-

strength indicator (RSSI) and an ASK demodulator, and

analog baseband data-recovery circuitry.

The MAX1470 is available in a 28-pin TSSOP package.

Applications

● Remote Keyless Entry

● Garage Door Openers

● Remote Controls

● Wireless Sensors

● Wireless Computer Peripherals

● Security Systems

● Toys

● Video Game Controllers

● Medical Systems

Features

● Operates from a Single +3.0V to +3.6V Supply

● Built-In 53dB RF Image Rejection

● -115dBm Receive Sensitivity*

● 250μs Startup Time

● Low 5.5mA Operating Supply Current

● 1.25μA Low-Current Power-Down Mode for Efficient

Power Cycling

● 250MHz to 500MHz Operating Band

(Image Rejection Optimized at 315MHz)

● Integrated PLL with On-Board Voltage-Controlled

Oscillator (VCO) and Loop Filter

● Selectable IF Bandwidth Through External Filter

● Complete Receive System from RF to Digital Data Out

Typical Application Circuit and Pin Configuration appear at

end of data sheet.

19-2135; Rev 1; 9/14

*See Note 2, AC Electrical Characteristics.

PART TEMP RANGE PIN-PACKAGE

MAX1470EUI -40°C to +85°C 28 TSSOP

LNA

LNAOUT

MIXIN1 MIXIN2

0°

90°

IFIN1MIXOUT IFIN2

181712

RSSI

DF1

100kΩ

DF2

100kΩ

DIVIDE

BY 64

VCO

LOOP

FILTER

PHASE

DETECTOR

CRYSTAL

DRIVER

SHUTDOWN

8 9

LIMITING

AMPS

22212619202527281

DFOPPPDOUTDSPDSNDATAOUTPWRDNXTAL1 XTAL2

5,10

2,7

AGND

DGND

LNASRC

LNAIN

DATA

SLICER

DATA

FILTER

MAX1470

PEAK

DETECTOR

MAX1470 315MHz Low-Power, +3V Superheterodyne

Receiver

Functional Diagram

Ordering Information

Summary of content (12 pages)

PAGE 1
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver General Description Features ●● ●● ●● ●● ●● ●● The MAX1470 is a fully integrated low-power CMOS superheterodyne receiver for use with amplitude-shiftkeyed (ASK) data in the 315MHz band. With few required external components, and a low-current power-down mode, it is ideal for cost- and power-sensitive applications in the consumer markets.
PAGE 2
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver Absolute Maximum Ratings AVDD to AGND ......................................................-0.3V to +4.0V DVDD to DGND......................................................-0.3V to +4.0V All Other Pins Referenced to AGND...........-0.3V to (VDD + 0.3V) Continuous Power Dissipation (TA = +70°C) 28-Pin TSSOP (derate 13mW/°C above +70°C).......1039mW Operating Temperature Range MAX1470EUI...................................................
PAGE 3
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver AC Electrical Characteristics (continued) (Typical Application Circuit, all RF inputs and outputs are referenced to 50Ω, VDD = +3.3V, TA = +25°C, fRFIN = 315MHz, unless otherwise noted.) (Note 1) PARAMETER Noise Figure SYMBOL CONDITIONS MIN NFLNA Power Gain TYP MAX UNITS 2.
PAGE 4
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver Typical Operating Characteristics (VDD = +3.3V, TA = +25°C, unless otherwise noted. Typical Application Circuit.) 5.5 TA = +25°C 5.1 MAX1470 toc02 1.8 1 1.6 1.4 2.9 3.1 3.3 0.1 3.5 1.0 -114 -140 -120 55 -40 -20 0 20 40 60 50 45 80 -40 -20 TEMPERATURE (°C) LNA GAIN vs. RF FREQUENCY 20 15 60 53dB IMAGE REJECTION 20 10 -10 80 LOWER SIDEBAND TEMPERATURE (°C) 10 20 30 IF FREQUENCY (MHz) SUPPLY CURRENT vs.
PAGE 5
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver Typical Operating Characteristics (continued) (VDD = +3.3V, TA = +25°C, unless otherwise noted. Typical Application Circuit.) NORMALIZED IF GAIN vs. IF FREQUENCY IMAGE REJECTION (dB) -5 -10 -15 1 10 100 IF FREQUENCY (MHz) MAX1470 toc11 3dB BANDWIDTH = 11.7MHz 0 -20 60 MAX1470 toc10 NORMALIZED IF GAIN (dB) 5 IMAGE REJECTION vs.
PAGE 6
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver Pin Description PIN NAME FUNCTION 1 XTAL1 1st Crystal Input 2, 7 AVDD Positive Analog Supply Voltage for RF Sections. Decouple to AGND with 0.01µF capacitors. 3 LNAIN Low-Noise Amplifier Input 4 LNASRC 5, 10 AGND 6 LNAOUT 8 MIXIN1 1st Differential Mixer Input. Must be AC-coupled to driving input. 9 MIXIN2 2nd Differential Mixer Input. Must be AC-coupled to driving input. 11, 15, 16, 23, 24 I.C.
PAGE 7
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver ƒ= 1 2π L TOTAL × C TOTAL where: L TOTAL = C TOTAL = L1 + L PARASITICS C9 + C PARASITICS LPARASITICS and CPARASITICS include inductance and capacitance of the PC board traces, package pins, mixer input impedance, LNA output impedance, etc. These parasitics at high frequencies cannot be ignored and can have a dramatic effect on the tank filter center frequency. Lab experimentation should be done to optimize the center frequency of the tank.
PAGE 8
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver When the crystal is loaded as specified, i.e., Cload = Cspec, the frequency pulling equals zero. MAX1470 Data Filter The data filter is implemented as a 2nd-order lowpass Sallen-Key filter. The pole locations are set by the combination of two on-chip resistors and two external capacitors. Adjusting the value of the external capacitors changes the corner frequency to optimize for different data rates.
PAGE 9
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver DATA FILTER MAX1470 MAX1470 DATA FILTER DATA SLICER 25 20 DSN DATA SLICER 19 DSP 25 DATA OUT C4 20 DSN R1 DATA OUT 47nF 25kΩ Figure 2. Generating Data Slicer Threshold Figure 3. Using PDOUT for Faster Startup detector to dynamically follow peak changes of the data filter output voltage. For faster receiver startup, the circuit shown in Figure 3 can be used. Layout Considerations 433.
PAGE 10
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver Typical Application Circuit +3.3V Y1 4.7547MHz C12 0.01µF ANTENNA (RFIN) C7 100pF L2 100nH L3 15nH +3.3V L1 27nH 1 XTAL1 XTAL2 28 2 AVDD PWRDN 27 3 LNAIN PDOUT 26 4 LNASRC 5 AGND I.C. 24 6 LNAOUT I.C. 23 7 AVDD 8 MIXIN1 C2 0.01µF C11 100pF MAX1470 9 C8 100pF DF 22 OPP 21 MIXIN2 C5 470pF DSN 20 10 AGND C1 0.01µF www.maximintegrated.com DATAOUT 25 DATAOUT C9 2.2pF C10 220pF SHUTDOWN DSP 19 11 I.C.
PAGE 11
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver Pin Configuration TOP VIEW XTAL1 1 28 XTAL2 AVDD 2 27 PWRDN LNAIN 3 26 PDOUT LNASRC 4 AGND 5 LNAOUT 6 25 DATAOUT MAX1470 AVDD 7 24 I.C. 23 I.C. 22 DF MIXIN1 8 21 OPP MIXIN2 9 20 DSN AGND 10 19 DSP I.C. 11 18 IFIN2 MIXOUT 12 17 IFIN1 DGND 13 16 I.C. DVDD 14 15 I.C. TSSOP Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages.
PAGE 12
MAX1470 315MHz Low-Power, +3V Superheterodyne Receiver Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 0 8/01 Initial release — 1 9/14 Removed automotive reference from page 1 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.