Maxim MAX1470EUI Datasheet
General Description
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 automotive and 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
MAX1470
315MHz Low-Power, +3V Superheterodyne
Receiver
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-2135; Rev 1; 8/02
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.
Functional Diagram
Typical Application Circuit appears at end of data sheet.
Pin Configuration appears at end of data sheet.
*See Note 2, AC Electrical Characteristics.
PART TEMP RANGE PIN-PACKAGE
MAX1470EUI -40°C to +85°C 28 TSSOP
LNAOUT6MIXIN1 MIXIN2
89
3
LNAIN
LNASRC
DV
AV
DGND
AGND
DD
DD
LNA
DATA
SLICER
Q
I
MAX1470
4
DIVIDE
14
BY 64
2,7
PHASE
DETECTOR
13
CRYSTAL
5,10
DRIVER
VCO
LOOP
FILTER
SHUTDOWN
0°
90°
PEAK
DETECTOR
IFIN1MIXOUT IFIN2
RSSI
R
DF2
100kΩ
181712
DATA
FILTER
IF
LIMITING
AMPS
R
DF1
100kΩ
22212619202527281
DFOPPPDOUTDSPDSNDATAOUTPWRDNXTAL1 XTAL2
MAX1470
315MHz Low-Power, +3V Superheterodyne
Receiver
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(Typical Application Circuit, VDD= +3.0V to +3.6V, no RF signal applied, TA= -40°C to +85°C. Typical values are at VDD= +3.3V, T
A
= +25°C, unless otherwise noted.) (Note 1)
AC ELECTRICAL CHARACTERISTICS
(Typical Application Circuit, all RF inputs and outputs are referenced to 50Ω, VDD= +3.3V, TA= +25°C, f
RFIN
= 315MHz, unless oth-
erwise 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.
AVDDto AGND ......................................................-0.3V to +4.0V
DV
DD
to DGND......................................................-0.3V to +4.0V
All Other Pins Referenced to AGND...........-0.3V to (V
DD
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
28-Pin TSSOP (derate 13mW/°C above +70°C) .........1039mW
Operating Temperature Range
MAX1470EUI ...................................................-40°C to +85°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage V
Supply Current I
Shutdown Supply Current I
PWRDN Voltage Input Low V
PWRDN Voltage Input High V
DATAOUT Voltage Output Low V
DATAOUT Voltage Output High V
DD
DD
SHUTDOWN
IL
IH
OL
OH
PWRDN = V
PWRDN = GND 1.25 µA
I
DATAOUT
I
DATAOUT
= 100µA 0.4 V
= -100µA
3.0 3.6 V
DD
VDD -
0.4
V
DD
0.4
5.5 mA
0.4 V
-
V
V
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
GENERAL CHARACTERISTICS
Maximum Startup Time T
Maximum Receiver Input Level RFIN
Minimum Receiver Input Level,
315MHz
Minimum Receiver Input Level,
433.92MHz
Receivers f
LOW-NOISE AMPLIFIER (LNA)
Input Impedance S11
1dB Compression Point P1dB
Input-Referred 3rd-Order
Intercept
LO Signal Feedthrough to
Antenna
Output Impedance S22
RFIN
RFIN
IIP3
Time from PWRDN deasserting to valid data
ON
out
Modulation depth ≥ 60dB 0 dBm
MAX
Average carrier power level (Note 2) -115
MIN
Peak power level (Note 2) -109
Average carrier power level (Note 2) -110
Peak power level (Note 2) -104
Normalized to 50Ω (Note 3) 1 - j4
LNA
LNA
LNA
Normalized to 50Ω
LNA
250 µs
dBm
dBm
250 to 500 MHz
-22 dBm
-18 dBm
-95 dBm
0.12 j4.4
MAX1470
315MHz Low-Power, +3V Superheterodyne
Receiver
_______________________________________________________________________________________ 3
AC ELECTRICAL CHARACTERISTICS (continued)
(Typical Application Circuit, all RF inputs and outputs are referenced to 50Ω, VDD= +3.3V, TA= +25°C, f
RFIN
= 315MHz, unless oth-
erwise noted.) (Note 1)
Note 1: Parts are production tested at T
A
= +25°C; Min and Max values are guaranteed by design and characterization.
Note 2: BER = 2E-3, Manchester encoded, data rate = 4kbps, IF bandwidth = 350kHz.
Note 3: Input impedance is measured at the LNAIN pin. Note that the impedance includes the 15nH inductive degeneration con-
nected from the LNASRC.
Note 4: Guaranteed by production test.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Noise Figure NF
Power Gain 16 dB
MIXER
Input Impedance S11
Input-Referred 3rd-Order
Intercept
Output Impedance Z
Image Rejection
Noise Figure NF
Conversion Gain 330Ω IF filter load 13 dB
INTERMEDIATE-FREQUENCY DEMODULATOR BLOCK
Input Impedance ZIN_
Operating Frequency f
RSSI Linearity ±1dB
RSSI Dynamic Range 65 dB
RSSI Level
DATA FILTER
Maximum Bandwidth BW
DATA SLICER
Comparator Bandwidth BW
Maximum Load Capacitance C
CRYSTAL OSCILLATOR
Reference Frequency f
LNA
MIX
IIP3
MIX
OUT_MIX
MIX
IF
IF
DF
CMP
LOAD
REF
Normalized to 50Ω
f
= 315M H z, fRF_
RFIN
= 433.92M H z, fRF_
f
RFIN
P
< -120dBm 1.2
RFIN
> -50dBm 2.0
P
RFIN
= 293.6M H z ( N ote 4) 40 53
IM AGE
= 412.52M H z39
IM AGE
2.0 dB
0.25 j2.4
-18 dBm
330 Ω
16 dB
330 Ω
10.7 MHz
100 kHz
100 kHz
10 pF
4.7547 MHz
dB
V
MAX1470
315MHz Low-Power, +3V Superheterodyne
Receiver
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VDD= +3.3V, TA= +25°C, unless otherwise noted. Typical Application Circuit.)
4.7
5.1
4.9
5.5
5.3
5.9
5.7
6.1
2.7 3.12.9 3.3 3.5
SUPPLY CURRENT vs.
SUPPLY VOLTAGE
MAX1470 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
TA = +85°C
TA = +25°C
TA = -40°C
10
0.1
-120 -116 -114
1
AVERAGE RF INPUT POWER (dBm)
BIT-ERROR RATE (%)
-118
BIT-ERROR RATE vs. AVERAGE
RF INPUT POWER
MAX1470 toc02
1.0
1.4
1.2
1.8
1.6
2.0
2.2
-140 -80 -60-120 -100 -40 -20
RSSI vs. AVERAGE RF INPUT POWER
MAX1470 toc03
AVERAGE RF INPUT POWER (dBm)
RSSI (V)
IF BANDWIDTH = 350kHz
-116.0
-116.5
-117.0
-117.5
-118.0
-40 20-20 0 40 60 80
RECEIVER SENSITIVITY
vs. TEMPERATURE
MAX1470 toc04
TEMPERATURE (°C)
RECEIVER SENSITIVITY (dBm)
AVERAGE RF INPUT POWER
1% BER
IF BANDWIDTH = 350kHz
45
50
55
60
IMAGE REJECTION vs. TEMPERATURE
MAX1470 toc05
TEMPERATURE (°C)
IMAGE REJECTION (dB)
-40 20 40-20 0 60 80
-10
10
0
30
20
50
40
60
SYSTEM GAIN vs. IF FREQUENCY
MAX1470 toc06
IF FREQUENCY (MHz)
SYSTEM GAIN (dB)
0 10203040
FROM RFIN TO MIXOUT
f
LO
= 304.3MHz
UPPER SIDEBAND
LOWER SIDEBAND
53dB IMAGE
REJECTION
30
25
20
15
10
250 325275 300 350 375
LNA GAIN vs. RF FREQUENCY
MAX1470 toc07
RF FREQUENCY (MHz)
LNA GAIN (dB)
LC TANK
FILTER TUNED
TO 315MHz
4.2
5.2
4.7
6.2
5.7
6.7
7.2
150 300 350200 250 400 450 500
SUPPLY CURRENT
vs. LO FREQUENCY
MAX1470 toc08
LO FREQUENCY (MHz)
SUPPLY CURRENT (mA)
0
20
10
40
30
60
50
70
1 10 100
INPUT IMPEDANCE vs.
INDUCTIVE DEGENERATION
MAX1470 toc09
INDUCTIVE DEGENERATION (nH)
REAL IMPEDANCE (Ω)
-350
-250
-300
-150
-200
-50
-100
0
IMAGINARY IMPEDANCE (Ω)
REAL IMPEDANCE
IMAGINARY IMPEDANCE
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