Maxim MAX2451CSE Datasheet
19-0493; Rev 0; 12/95
EVALUATION KIT
AVAILABLE
3V, Ultra-Low-Power
Quadrature Demodulator
_______________General Description
The monolithic MAX2451 is a quadrature demodulator
with a supporting oscillator and divide-by-8 prescaler. It
operates from a single +3V supply and draws only
5.5mA. The demodulator accepts an amplified and filtered IF signal in the 35MHz to 80MHz range, and
demodulates it into I and Q baseband signals with
51dB of voltage conversion gain. The IF input is terminated with a 400Ω thin-film resistor for matching to an
external IF filter. The baseband outputs are fully differential and have 1.2Vp-p signal swings.
Pulling the CMOS-compatible ENABLE pin low shuts
down the MAX2451 and reduces the supply current to
less than 2µA, typical. To minimize spurious feedback,
the MAX2451’s internal oscillator is set at twice the IF
frequency via external tuning components. The
MAX2451 comes in a 16-pin narrow SO package.
________________________Applications
Digital Cordless Phones
GSM and North American Cellular Phones
Wireless LANs
Digital Communications
Pagers
__________________Pin Configuration
TOP VIEW
IF
GND
GND
N.C.
ENABLE
PRE_OUT
LO_V
TANK
1
2
3
MAX2451
4
5
6
7
CC
8
SO
16
15
14
13
12
11
10
9
GND
V
CC
I
I
Q
Q
LO_GND
TANK
____________________________Features
♦ Integrated Quadrature Phase Shifters
♦ On-Chip Oscillator (Requires External Tuning
Circuit)
♦ 51dB Voltage Conversion Gain
♦ On-Chip Divide-by-8 Prescaler
♦ Baseband Output Bandwidth Up to 9MHz
♦ CMOS-Compatible Enable
♦ 5.5mA Operating Supply Current
2µA Shutdown Supply Current
______________Ordering Information
PART
MAX2451CSE 0°C to +70°C
TEMP. RANGE PIN-PACKAGE
16 Narrow SO
________________Functional Diagram
14
I
13
12
11
6
I
Q
Q
PRE_OUT
LO_V
TANK
TANK
LO_GND
V
1
IF
400Ω
7
CC
8
9
10
LOCAL
OSCILLATOR
15
CC
BANDGAP BIAS
DEMODULATOR
0°
÷ 2 ÷ 4
QUADRATURE
PHASE
GENERATOR
÷ 2
MASTER BIAS
PRESCALER
90°
52, 3, 16
ENABLEGND
BIAS
MAX2451
MAX2451
________________________________________________________________
Maxim Integrated Products
Call toll free 1-800-998-8800, or visit our WWW site at http://www.maxim-ic.com
for free samples or the latest literature.
1
3V, Ultra-Low-Power
Quadrature Demodulator
ABSOLUTE MAXIMUM RATINGS
VCC, LO_VCCto GND............................................-0.3V to +4.5V
ENABLE, TANK, TANK
to GND.............................................-0.3V to (VCC+ 0.3V)
Q, Q
IF to GND...............................................................-0.3V to +1.5V
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.
MAX2451
, I, I,
DC ELECTRICAL CHARACTERISTICS
(VCC= LO_VCC= TANK = +2.7V to +3.3V, ENABLE = VCC- 0.4V, GND = LO_GND = 0V, I = I = Q = Q = IF = TANK = OPEN,
= 0°C to +70°C, unless otherwise noted.)
T
A
Supply Voltage Range
Supply Current
Shutdown Supply Current
Enable/Disable Time
ENABLE Bias Current
ENABLE High Voltage
ENABLE Low Voltage
IF Input Impedance
I, I, Q, Q Voltage Level
VCC,
LO_V
CC(ON)
CC(OFF)
ON/OFF
EN
ENH
ENL
IN
V
I/
I
V
Q/Q
CC
Enable = 0.4V
,
Continuous Power Dissipation (T
Narrow SO (derate 8.70mW/°C above +70°C) .............696mW
Operating Temperature Range...............................0°C to +70°C
Storage Temperature Range.............................-65°C to +165°C
Lead Temperature (soldering, 10sec).............................+300°C
CONDITIONS
= +70°C)
A
UNITSMIN TYP MAXSYMBOLPARAMETER
V2.7 3.3
mA5.5 7.4I
µA220I
µs10t
µA13I
VVCC- 0.4V
V0.4V
Ω320 400 480Z
V1.2
mV±11 ±50Baseband I and Q DC Offset
AC ELECTRICAL CHARACTERISTICS
VCC= LO_VCC= ENABLE = 3.0V, fLO= 140MHz, fIF= 70.1MHz, VIF= 2.82mVp-p, TA= +25°C, unless otherwise noted.)
CONDITIONS
Baseband I and Q Amplitude
Balance
Baseband I and Q Phase Accuracy
(Note 1)
I and Q IM3 Level
I and Q IM5 Level
I and Q Signal 3dB Bandwidth
Oscillator Frequency Range
PRE_OUT Output Voltage
PRE_OUT Slew Rate
Note 1: Guaranteed by design, not tested.
Note 2: f
Note 3: Oscillator frequencies up to 1GHz (500MHz IF) by externally overdriving (see
2 _______________________________________________________________________________________
= 2 tones at 70.10MHz and 70.11MHz, VIF= 1.41mVp-p per tone.
IF
LO
PRE_OUT
PRE_OUT
I/Q
I/Q
3dB
(Note 2)
(Note 2)
(Notes 1, 3)
RL= 10kΩ, CL< 6pF Vp-p0.35V
RL= 10kΩ, CL< 6pF, rising edge V/µs60SR
Offset = 10kHz dBc/Hz-80Oscillator Phase Noise
Applications Information
).
UNITSMIN TYP MAXSYMBOLPARAMETER
dB< ±0.45
degrees< ±1.3
dB51Voltage Conversion Gain
dB18NFNoise Figure
Vp-p1.35Allowable I and Q Voltage Swing
dBc-44IM3
dBc-60IM5
MHz9BW
MHz70 160f
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