Maxim MAX2450CEP Datasheet

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].

General Description

The MAX2450 combines a quadrature modulator and
quadrature demodulator with a supporting oscillator and
divide-by-8 prescaler on a monolithic IC. It operates
from a single +3V supply and draws only 5.9mA. 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 thin­film resistor for matching to an external IF filter. The
baseband outputs are fully differential and have 1.2Vp-p
signal swings. The modulator accepts differential I and
Q baseband signals with amplitudes up to 1.35Vp-p
and bandwidths to 15MHz, and produces a differential
IF signal in the 35MHz to 80MHz range.

Pulling the CMOS-compatible ENABLE pin low shuts
down the MAX2450 and reduces the supply current to
less than 1µA. To minimize spurious feedback, the
MAX2450’s internal oscillator is set at twice the IF via
external tuning components. The oscillator and associ­ated phase shifters produce differential signals exhibit­ing low amplitude and phase imbalance, yielding
modulator sideband rejection of 38dB. The MAX2450
comes in a QSOP package.

Applications

Digital Cordless Phones
GSM and North American Cellular Phones
Wireless LANs
Digital Communications
Two-Way Pagers

____________________________Features

♦ Combines Quadrature Modulator and

Demodulator

♦ Integrated Quadrature Phase Shifters
♦ On-Chip Oscillator (Requires External Tuning

Circuit)

♦ On-Chip Divide-by-8 Prescaler
♦ Modulator Input Bandwidth Up to 15MHz
♦ Demodulator Output Bandwidth Up to 9MHz
♦ 51dB Demodulator Voltage Conversion Gain
♦ CMOS-Compatible Enable
♦ 5.9mA Operating Supply Current

1µA Shutdown Supply Current

MAX2450

3V, Ultra-Low-Power Quadrature

Modulator/Demodulator

________________________________________________________________

Maxim Integrated Products

1

ENABLEGND

400Ω

2

IF_OUT

1

83, 19

IF_OUT

9

PRE_OUT

14

Q_OUT

15

Q_OUT

16

I_OUT

17

I _OUT

20

IF_IN

10

LO_V

CC

11

TANK

12

TANK

4

I_IN

5

I_IN

6

Q_IN

7

Q_IN

18

V

CC

13

LO_GND

BIAS

PRESCALER

MODULATOR

DEMODULATOR

QUADRATURE

PHASE

GENERATOR

LOCAL

OSCILLATOR

÷ 2 ÷ 4

BANDGAP BIAS

MASTER BIAS

÷ 2

Σ

0°

90°

MAX2450

Functional Diagram

20
19
18
17
16
15
14
13

1
2
3
4
5
6
7
8

IF_IN
GND
V

CC

I_OUT
I_OUT
Q_OUT
Q_OUT
LO_GND
TANK
TANK

IF_OUT
IF_OUT

GND

I_IN

I_IN
Q_IN
Q_IN

ENABLE

PRE_OUT

LO_V

CC

TOP VIEW

12
11

9

10

QSOP

MAX2450

Pin Configuration

19-0455; Rev 1; 9/98

PART

MAX2450CEP 0°C to +70°C

TEMP. RANGE PIN-PACKAGE

EVALUATION KIT

AVAILABLE

Ordering Information

20 QSOP

MAX2450

3V, Ultra-Low-Power Quadrature
Modulator/Demodulator

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= LO_VCC= TANK = 2.7V to 3.3V, ENABLE = V

CC

- 0.4, GND = LO_GND = 0V, I_IN = I_IN = Q_IN = Q_IN = IF_IN = TANK =

OPEN, T

A

= 0°C to +70°C, unless otherwise noted.)

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.

VCC, LO_VCCto GND............................................-0.3V to +4.5V

ENABLE, TANK, TANK, I_IN, I_IN

, Q_IN,

Q_IN

to GND..................................................-0.3V to (VCC+ 0.3V)

IF_IN to GND.........................................................-0.3V to +1.5V

Continuous Power Dissipation (T

A

= +70°C)

QSOP (derate 9.1mW/°C above +70°C)......................727mW

Operating Temperature Range...............................0°C to +70°C

Storage Temperature Range.............................-65°C to +165°C

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

ENABLE = 0.4V

ENABLE = V

CC

CONDITIONS

V1.2

V

I_OUT/I_OUT

,

V

Q_OUT/Q_OUT

I_OUT, I_OUT, Q_OUT, Q_OUT
DC Bias Voltage Level

µA220I

CC(OFF)

Shutdown Supply Current

mA5.9 8.2I

CC(ON)

V2.7 3.3VCC, LO_V

CC

Supply Voltage Range
Supply Current

Ω320 400 480Z

IF_IN

Demodulator IF Input Impedance

VVCC- 1.5V

IF_OUT/IF_OUT

IF_OUT, IF_OUT DC Bias Voltage

kΩ35 44

Z

I_IN/I_IN

,

Z

Q_IN/Q_IN

Modulator Differential Input
Impedance

V1.25 1.5 1.75

V

I_IN/I_IN

,

V

Q_IN/Q_IN

I_IN, I_IN, Q_IN, Q_IN
Self-Bias DC Voltage Level

µs10t

ON/OFF

Enable/Disable Time

µA13I

EN

ENABLE Bias Current

VVCC- 0.4V

ENH

ENABLE High Voltage

V0.4V

ENL

ENABLE Low Voltage

UNITSMIN TYP MAXSYMBOLPARAMETER

AC ELECTRICAL CHARACTERISTICS

(MAX2450 EV kit, VCC= LO_VCC= ENABLE = 3.0V, fLO= 140MHz, f

I_IN/I_IN

= f

Q_IN/Q_IN

= 600kHz, V

I_IN/I_IN

= V

Q_IN/Q_IN

= 1.2V

p-p

,

f

IF_IN

= 70.1MHz, V

IF_IN

= 2.82mV

p-p

, TA= +25°C, unless otherwise noted.)

(Note 2)

(Note 2)

CONDITIONS

dB< ±0.45I and Q Amplitude Balance

dBc-60IM5

I/Q

I and Q IM5 Level

dBc-44IM3

I/Q

I and Q IM3 Level

degrees< ±1.3I and Q Phase Accuracy

dB51Voltage Conversion Gain

UNITSMIN TYP MAXSYMBOLPARAMETER

RL= 10kΩ, CL< 6pF, rising edge

(Notes 1, 3)
10kHz offset
RL= 10kΩ, CL< 6pF

MHz9BW

DEMOD

I and Q Signal 3dB Bandwidth

V/µs60SR

PRE_OUT

PRE_OUT Slew Rate

MHz70 160f

LO

Oscillator Frequency Range

dBc/Hz-80LO Phase Noise

V

p-p

0.35V

PRE_OUT

PRE_OUT Output Voltage

(Note 1) V

p-p

1.35Allowable I and Q Voltage Swing

mV±11 ±50

Demodulator I and Q Baseband
DC Offset

dB18NFNoise Figure

DEMODULATOR

MAX2450

3V, Ultra-Low-Power Quadrature

Modulator/Demodulator

_______________________________________________________________________________________

3

7.0

6.8

6.6

6.4

6.2

6.0

5.8

5.6

5.4

5.2

5.0
0

10

20 30 40 50 60 70 80

MAX2450-01

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

SUPPLY CURRENT

vs. TEMPERATURE

V

CC

= 2.7V

V

CC

= 3.3V

V

CC

= 3.0V

0

2

4

6

8

10

12

0

10

20 30 40

50

60 70 80

MAX2450-02

TEMPERATURE (°C)

V

CC

= 2.7V

V

CC

= 3.3V

V

CC

= 3.0V

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

SUPPLY CURRENT (µA)

-30

-34

-38

-42

-46

-50

-54

-26 -22 -18 -14 -10 -6

MAX2450-03

BASEBAND INPUT (dBV

RMS

)

OUTPUT (dBV

RMS

)

MODULATOR IF OUTPUT

vs. BASEBAND INPUT

Vp-p = 2 2 x 10 (V)

dBV

RMS

20

(Note 1)

V

I_IN/I_IN

, = V

Q_IN/Q_IN = 1.2Vp-p,

RL= 200kΩ differential,
CL< 5pF differential

V

I_IN/I_IN

= 1.35Vp-p composite

(Note 4)
V

I_IN/I_IN

= 1.35Vp-p composite

(Note 4)

CONDITIONS

V1.25 1.75Input Common-Mode Voltage Range

V

p-p

1.35

V

I_IN/I_IN

,

V

Q_IN/Q_IN

Allowable Differential Input Voltage

dBc-36

Carrier Suppression at Modulator
Output

dBc38Sideband Rejection

MHz15BW

MOD

I and Q Signal 3dB Bandwidth

mV

p-p

65V

IF_OUT/IF_OUT

IF Differential Output Voltage

dBc-60IM3

IF

IF Output IM3 Level

dBc-60IM5

IF

IF Output IM5 Level

UNITSMIN TYP MAXSYMBOLPARAMETER

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2450 EV kit, VCC= LO_VCC= ENABLE = 3.0V, fLO= 140MHz, f

I_IN/I_IN

= f

Q_IN/Q_IN

= 600kHz, V

I_IN/I_IN

= V

Q_IN/Q_IN

= 1.2V

p-p

,

f

IF_IN

= 70.1MHz, V

IF_IN

= 2.82mV

p-p

, TA= +25°C, unless otherwise noted.)

MODULATOR

Note 1: Guaranteed by design, not tested.
Note 2: f

IF_IN

= 2 tones at 70.10MHz and 70.11MHz. V

IF_IN

= 1.41mVp-p per tone.

Note 3: The frequency range can be extended in either direction, but has not been characterized. At higher frequencies, the

modulator IF output amplitude may decrease and distortions may increase.

Note 4: Q_IN/Q_IN

ports are terminated. f

I_IN/I_IN

= 2 tones at 550kHz and 600kHz.

__________________________________________Typical Operating Characteristics

(MAX2450 EV kit, VCC= LO_VCC= ENABLE = 3.0V, fLO= 140MHz, f

I_IN/I_IN

= f

Q_IN/Q_IN

= 600kHz, V

I_IN/I_IN

= V

Q_IN/Q_IN

= 1.2V

p-p

,

f

IF_IN

= 70.1MHz, V

IF_IN

= 2.82mV

p-p

, TA= +25°C, unless otherwise noted.)