MAXIM MAX9985 Technical data

General Description

The MAX9985 high-linearity, dual-channel downconver­sion mixer is designed to provide approximately 6dB
gain, +28.5dBm of IIP3, and 10.5dB of noise figure (NF)
ideal for diversity receiver applications. With a 700MHz
to 1000MHz RF frequency range and a 570MHz to
865MHz LO frequency range, this mixer is ideal for low­side LO injection architectures. In addition, the broad
frequency range makes the MAX9985 ideal for GSM
850/950, 2G/2.5G EDGE, WCDMA, cdma2000

®

, and

iDEN®base-station applications.

The MAX9985 dual-channel downconverter achieves a
high level of component integration. The MAX9985 inte­grates two double-balanced active mixer cores, two LO
buffers, a dual-input LO selectable switch, and a pair of
differential IF output amplifiers. In addition, integrated
on-chip baluns at the RF and LO ports allow for single­ended RF and single-ended LO inputs. The MAX9985
requires a typical 0dBm LO drive. Supply current is
adjustable up to 400mA.

The MAX9985 is available in a 36-pin thin QFN pack­age (6mm x 6mm) with an exposed paddle. Electrical
performance is guaranteed over the extended tempera­ture range, from TC= -40°C to +85°C.

Applications

850MHz WCDMA Base Stations

GSM 850/GSM 950, 2G/2.5G EDGE Base
Stations

cdmaOne™ and cdma2000 Base Stations

iDEN Base Stations

Fixed Broadband Wireless Access

Wireless Local Loop

Private Mobile Radios

Military Systems

Digital and Spread-Spectrum Communication
Systems

Microwave Links

Features

 700MHz to 1000MHz RF Frequency Range

 570MHz to 865MHz LO Frequency Range

 50MHz to 250MHz IF Frequency Range

 6dB Typical Conversion Gain

 10.5dB Typical Noise Figure

 +28.5dBm Typical Input IP3

 +16.2dBm Typical Input 1dB Compression Point

 77dBc Typical 2RF-2LO Spurious Rejection at

P

RF

= -10dBm

 Dual Channels Ideal for Diversity Receiver

Applications

 47dB Typical Channel-to-Channel Isolation

 -3dBm to +3dBm LO Drive

 Integrated LO Buffer

 Internal RF and LO Baluns for Single-Ended

Inputs

 Built-In SPDT LO Switch with 43dB LO1-to-LO2

Isolation and 50ns Switching Time

 Pin-Compatible with MAX9995/MAX9995A

1700MHz to 2200MHz Mixers

 Lead-Free Package Available

MAX9985

Dual, SiGe, High-Linearity, 700MHz to 1000MHz

Downconversion Mixer with LO Buffer/Switch

________________________________________________________________

Maxim Integrated Products

1

Ordering Information

19-0705 Rev 0; 1/07

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.

*

EP = Exposed paddle.

T = Tape-and-reel package.

+

Denotes lead-free and RoHS compliant.

cdma2000 is a registered trademark of Telecommunications
Industry Association.

iDEN is a registered trademark of Motorola, Inc.

cdmaOne is a trademark of CDMA Development Group.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX9985ETX -40°C to +85°C

MAX9985ETX-T -40°C to +85°C

MAX9985ETX+ -40°C to +85°C

MAX9985ETX+T -40°C to +85°C

36 Thi n QFN- E P *

(6mm x 6mm)

36 Thi n QFN- E P *

(6mm x 6mm),

T/R

36 Thi n QFN- E P *

(6mm x 6mm),
lead free, bulk

36 Thi n QFN- E P *

(6mm x 6mm),

lead free, T/R

PKG

CODE

T3666-2

T3666-2

T3666-2

T3666-2

MAX9985

Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(Using the

Typical Application Circuit

, no input RF or LO signals applied, VCC= 4.75V to 5.25V, TC= -40°C to +85°C. Typical values

are at V

CC

= 5.0V, TC= +25°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.

VCCto GND...........................................................-0.3V to +5.5V

LO1, LO2 to GND ...............................................................±0.3V

Any Other Pins to GND...............................-0.3V to (V

CC

+ 0.3V)

RFMAIN, RFDIV, and LO_ Input Power ..........................+20dBm

RFMAIN, RFDIV Current (RF is DC shorted to GND through

balun) ...............................................................................50mA

Continuous Power Dissipation (T

C

= +70°C) (Note A)

36-Pin Thin QFN (derate 26mW/°C above +70°C) .........10.8W

Operating Temperature Range ...........................-40°C to +85°C

Maximum Junction Temperature Range..........................+150°C

θ

JA

.................................................................................+38°C/W

θ

JC

...................................................................................7.4°C/W

Storage Temperature Range .............................-65°C to +150°C

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

AC ELECTRICAL CHARACTERISTICS

(Using the

Typical Application Circuit

, VCC= 4.75V to 5.25V, RF and LO ports are driven from 50Ω sources, PLO= -3dBm to +3dBm,

P

RF

= -5dBm, fRF= 820MHz to 920MHz, fLO= 670MHz to 865MHz, fIF= 100MHz, fRF> fLO, TC= -40°C to +85°C. Typical values are at

V

CC

= 5.0V, PRF= -5dBm, PLO= 0dBm, fRF= 870MHz, fLO= 770MHz, fIF= 100MHz, TC= +25°C, unless otherwise noted.) (Note 1)

Note A: TCis the temperature on the exposed paddle of the package.

Supply Voltage V

Supply Current I

LOSEL Input High Voltage V

LOSEL Input Low Voltage V

LOSEL Input Current IIH and I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC

Total supply current (see Table 1 for lower
current settings)

CC

VCC (pin 16) 80

VCC (pin 30) 80

IFM+/IFM- (total of both) 105

IFD+/IFD- (total of both) 105

IH

IL

IL

4.75 5 5.25 V

400 440

2V

0.8 V

-10 +10 µA

mA

RF Frequency f

LO Frequency f

IF Frequency f

LO Drive P

Conversion Gain G

Gain Variation over Temperature -0.012 dB/°C

Conversion Gain Flatness

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RF

LO

(Note 2) 700 1000 MHz

(Note 2) 570 865 MHz

IF matching components affect the IF

IF

frequency range (Note 2)

(Note 3) -3 +3 dBm

LO

(Note 6) 4.5 6 7.5 dB

C

Fl atness over any one of thr ee fr equency b and s:

= 824MHz to 849MHz

f

RF

f

= 869MHz to 894MHz

RF

= 880MHz to 915MHz

f

RF

50 250 MHz

±0.1 dB

MAX9985

Dual, SiGe, High-Linearity, 700MHz to 1000MHz

Downconversion Mixer with LO Buffer/Switch

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS (continued)

(Using the

Typical Application Circuit

, VCC= 4.75V to 5.25V, RF and LO ports are driven from 50Ω sources, PLO= -3dBm to +3dBm,

P

RF

= -5dBm, fRF= 820MHz to 920MHz, fLO= 670MHz to 865MHz, fIF= 100MHz, fRF> fLO, TC= -40°C to +85°C. Typical values are at

V

CC

= 5.0V, PRF= -5dBm, PLO= 0dBm, fRF= 870MHz, fLO= 770MHz, fIF= 100MHz, TC= +25°C, unless otherwise noted.) (Note 1)

Noise Figure, Single Sideband NF fIF = 190MHz, no blockers present (Note 3) 10.5 13 dB

Noise Figure under Blocking
Condition

Input Compression Point P

Output Compression Point OP

Small-Signal Compression under
Blocking Conditions

Third-Order Input Intercept Point IIP3

Third-Order Input Intercept Point
Variation over Temperature

Third-Order Output Intercept
Point

2RF-2LO Spur 2 x 2

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

+11dBm blocker tone applied to RF port at

1dB

1dB

OIP3

961MHz, f
f

IFDESIRED

f

BLOCKER

P

= -5dBm, fRF =

RF

870MHz, f
= 871MHz

f

RF1-fRF2

= -5dBm/tone

P

RF

P

= -5dBm/tone, fIF = 100MHz,

RF

f

RF1-fRF2

= 870MHz, f

f

RF

= 770MHz, f
820MHz (Note 3)

= 860MHz, fLO = 670MHz,

RF

= 190MHz,

= 291MHz (Notes 3, 4)

P

BLOCKER

BLOCKER

= 1MHz, fIF = 100MHz,

= 1MHz (Note 3)

SPUR

P

BLOCKER

PRF = -10dBm 63 77

LO

=

= -5dBm 58 72

P

RF

21 26 dB

16.2 dBm

18.5 21.2 dBm

= +8dBm 0.1

= +11dBm 0.25

28.5 dBm

-0.01 dB/°C

32.0 34.5 dBm

dB

dBc

= 870MHz, f

f

3RF-3LO Spur 3 x 3

LO1-to-LO2 Port Isolation

Maximum LO Leakage at RF Port -40 -30 dBm

M axi m um 2LO Leakag e at RF P or t -45 -20 dBm

Maximum LO Leakage at IF Port -30 -20 dBm

Minimum RF-to-IF Isolation 30 45 dB

Minimum Channel-to-Channel
Isolation

RF

= 770MHz, f

803.3MHz (Note 3)

P

LO1

f

LO1-fLO2

= 100MHz (Notes 3, 5)

f

IF

= -10dBm, RFMAIN (RFDIV) power

P

RF

measured at IFDIV (IFMAIN), relative to
IFMAIN (IFDIV), all unused ports terminated
to 50Ω

SPUR

= +3dBm, P

= 1MHz, PRF = -5dBm,

PRF = -10dBm 70 85

LO

=

= -5dBm 60 75

P

RF

= +3dBm,

LO2

dBc

39 43 dB

40 47 dB

MAX9985

Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS (continued)

(Using the

Typical Application Circuit

, VCC= 4.75V to 5.25V, RF and LO ports are driven from 50Ω sources, PLO= -3dBm to +3dBm,

P

RF

= -5dBm, fRF= 820MHz to 920MHz, fLO= 670MHz to 865MHz, fIF= 100MHz, fRF> fLO, TC= -40°C to +85°C. Typical values are at

V

CC

= 5.0V, PRF= -5dBm, PLO= 0dBm, fRF= 870MHz, fLO= 770MHz, fIF= 100MHz, TC= +25°C, unless otherwise noted.) (Note 1)

Note 1: All limits reflect losses of external components. Output measurements taken at IF outputs of the

Typical Application Circuit

.

Note 2: Performance is guaranteed for f

RF

= 820MHz to 920MHz, fLO= 670MHz to 865MHz, and fIF= 100MHz. Operation outside

this range is possible, but with degraded performance of some parameters. See the

Typical Operating Characteristics

.

Note 3: Guaranteed by design and characterization.
Note 4: Measured with external LO source noise filtered so the noise floor is -174dBm/Hz. This specification reflects the effects of all

SNR degradations in the mixer including the LO noise, as defined in Maxim Application Note 2021.

Note 5: Measured at IF port at IF frequency. LOSEL may be in any logic state.
Note 6: Performance at T

C

= -40°C is guaranteed by design.

LO Switching Time

RF Input Impedance 50 Ω

LO Input Impedance 50 Ω

IF Output Impedance Differential 200 Ω

RF Input Return Loss LO on and IF terminated 24 dB

LO Input Return Loss

IF Return Loss RF terminated in 50Ω 20 dB

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

50% of LOSEL to IF settled within 2 degrees
(Note 3)

LO port selected 35

LO port unselected 36

0.05 1 µs

dB

MAX9985

Dual, SiGe, High-Linearity, 700MHz to 1000MHz

Downconversion Mixer with LO Buffer/Switch

_______________________________________________________________________________________

5

Typical Operating Characteristics

(Using the

Typical Application Circuit

, VCC= 5.0V, PLO= 0dBm, PRF= -5dBm, fRF> fLO, fIF= 100MHz, TC= +25°C, unless other-

wise noted.)

7

6

5

4

8

700 800 900 1000

CONVERSION GAIN vs. RF FREQUENCY

MAX9985 toc01

RF FREQUENCY (MHz)

CONVERSION GAIN (dB)

TC = +85°C

TC = +25°C

TC = -30°C

7

6

5

4

8

700 800 900 1000

CONVERSION GAIN vs. RF FREQUENCY

MAX9985 toc02

RF FREQUENCY (MHz)

CONVERSION GAIN (dB)

PLO = -3dBm, 0dBm, +3dBm

7

6

5

4

8

700 800 900 1000

CONVERSION GAIN vs. RF FREQUENCY

MAX9985 toc03

RF FREQUENCY (MHz)

CONVERSION GAIN (dB)

VCC = 4.75V, 5.0V, 5.25V

24

26

25

28

27

29

30

700 800 900 1000

INPUT IP3 vs. RF FREQUENCY

MAX9985 toc04

RF FREQUENCY (MHz)

INPUT IP3 (dBm)

TC = -30°C

TC = +25°C

TC = +85°C

24

26

25

28

27

29

30

700 800 900 1000

INPUT IP3 vs. RF FREQUENCY

MAX9985 toc05

RF FREQUENCY (MHz)

INPUT IP3 (dBm)

PLO = -3dBm, 0dBm, +3dBm

24

26

25

28

27

29

30

700 800 900 1000

INPUT IP3 vs. RF FREQUENCY

MAX9985 toc06

RF FREQUENCY (MHz)

INPUT IP3 (dBm)

VCC = 5.0V

VCC = 4.75V

VCC = 5.25V

7

9

8

11

10

13

12

14

700 800 900 1000

MAX9985 toc07

RF FREQUENCY (MHz)

NOISE FIGURE (dB)

NOISE FIGURE vs. RF FREQUENCY

TC = -30°C

TC = +25°C

TC = +85°C

7

9

8

11

10

13

12

14

700 800 900 1000

MAX9985 toc08

RF FREQUENCY (MHz)

NOISE FIGURE (dB)

NOISE FIGURE vs. RF FREQUENCY

PLO = -3dBm, 0dBm, +3dBm

7

9

8

11

10

13

12

14

700 800 900 1000

MAX9985 toc09

RF FREQUENCY (MHz)

NOISE FIGURE (dB)

NOISE FIGURE vs. RF FREQUENCY

VCC = 4.75V

VCC = 5.0V

VCC = 5.25V