19-4185; Rev 0; 8/08
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
General Description
The MAX19985A high-linearity, dual-channel, downcon-
version mixer is designed to provide approximately
8.7dB gain, +25.5dBm of IIP3, and 9.0dB of noise fig-
ure for 700MHz to 1000MHz diversity receiver applica-
tions. With an optimized LO frequency range of
900MHz to 1300MHz, this mixer is ideal for high-side
LO injection architectures in the cellular and new
700MHz bands. Low-side LO injection is supported by
the MAX19985, which is pin-pin and functionally com-
patible with the MAX19985A.
In addition to offering excellent linearity and noise per-
formance, the MAX19985A also yields a high level
of component integration. This device includes two
double-balanced passive mixer cores, two LO buffers,
a dual-input LO selectable switch, and a pair of differ-
ential IF output amplifiers. On-chip baluns are also inte-
grated to allow for single-ended RF and LO inputs.
The MAX19985A requires a nominal LO drive of 0dBm
and a typical supply current of 330mA at V
CC
= +5.0V
or 280mA at V
CC
= +3.3V.
The MAX19985/MAX19985A are pin compatible with
the MAX19995/MAX19995A series of 1700MHz to
2200MHz mixers and pin similar with the MAX19997A/
MAX19999 series of 1850MHz to 3800MHz mixers,
making this entire family of downconverters ideal for
applications where a common PCB layout is used
across multiple frequency bands.
The MAX19985A is available in a 6mm x 6mm, 36-pin
thin QFN package with an exposed pad. Electrical per-
formance is guaranteed over the extended temperature
range of T
C
= -40°C to +85°C.
Features
o
700MHz to 1000MHz RF Frequency Range
o
900MHz to 1300MHz LO Frequency Range
o
50MHz to 500MHz IF Frequency Range
o
8.7dB Typical Conversion Gain
o
9.0dB Typical Noise Figure
o
+25.5dBm Typical Input IP3
o
+12.6dBm Typical Input 1dB Compression Point
o
76dBc Typical 2LO-2RF Spurious Rejection at
P
RF
= -10dBm
o
Dual Channels Ideal for Diversity Receiver
Applications
o
48dB Typical Channel-to-Channel Isolation
o
Low -3dBm to +3dBm LO Drive
o
Integrated LO Buffer
o
Internal RF and LO Baluns for Single-Ended
Inputs
o
Built-In SPDT LO Switch with 46dB LO1-to-LO2
Isolation and 50ns Switching Time
o
Pin Compatible with the MAX19995/MAX19995A
Series of 1700MHz to 2200MHz Mixers
o
Pin Similar to the MAX19997A/MAX19999 Series
of 1850MHz to 3800MHz Mixers
o
Single +5.0V or +3.3V Supply
o
External Current-Setting Resistors Provide Option
for Operating Device in Reduced-Power/Reduced-
Performance Mode
MAX19985A
Applications
850MHz WCDMA and cdma2000
®
Base Stations
700MHz LTE/WiMAX™ Base Stations
GSM850/900 2G and 2.5G EDGE Base Stations
iDEN
®
Base Stations
Fixed Broadband Wireless Access
Wireless Local Loop
Private Mobile Radios
Military Systems
Ordering Information
PART
MAX19985AETX+
MAX19985AETX+T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
36 Thin QFN-EP*
36 Thin QFN-EP*
+Denotes
a lead-free/RoHS-compliant package.
*EP
= Exposed pad.
T = Tape and reel.
cdma2000 is a registered trademark of Telecommunications
Industry Association.
WiMAX is a trademark of WiMAX Forum.
iDEN is a registered trademark of Motorola, Inc.
Typical Application Circuit and Pin Configuration appear at
end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
MAX19985A
ABSOLUTE MAXIMUM RATINGS
V
CC
to 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 ..........................+15dBm
RFMAIN, RFDIV Current (RF is DC shorted
to GND through balun)....................................................50mA
Continuous Power Dissipation (Note 1) ..............................8.8W
θ
JA
(Notes 2, 3)..............................................................+38°C/W
θ
JC
(Note 3).....................................................................7.4°C/W
Operating Temperature Range (Note 4) .....T
C
= -40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
Based on junction temperature T
J
= T
C
+ (θ
JC
x V
CC
x I
CC
). This formula can be used when the temperature of the exposed
pad is known while the device is soldered down to a PCB. See the
Applications Information
section for details. The junction
temperature must not exceed +150°C.
Note 2:
Junction temperature T
J
= T
A
+ (θ
JA
x V
CC
x I
CC
). This formula can be used when the ambient temperature of the PCB is
known. The junction temperature must not exceed +150°C.
Note 3:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
Note 4:
T
C
is the temperature on the exposed pad of the package. T
A
is the ambient temperature of the device and PCB.
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.
+5.0V SUPPLY DC ELECTRICAL CHARACTERISTICS
(Typical
Application Circuit,
V
CC
= 4.75V to 5.25V, T
C
= -40°C to +85°C. Typical values are at V
CC
= 5.0V, T
C
= +25°C, all parame-
ters are production tested, unless otherwise noted.)
PARAMETER
Supply Voltage
Supply Current
LOSEL Input High Voltage
LOSEL Input Low Voltage
LOSEL Input Current
SYMBOL
V
CC
I
CC
V
IH
V
IL
I
IH
, I
IL
-10
2
0.8
+10
CONDITIONS
MIN
4.75
TYP
5
330
MAX
5.25
380
UNITS
V
mA
V
V
µA
+3.3V SUPPLY DC ELECTRICAL CHARACTERISTICS
(Typical
Application Circuit,
V
CC
= 3.0V to 3.6V, T
C
= -40°C to +85°C. Typical values are at V
CC
= 3.3V, T
C
= +25°C, all parameters
are guaranteed by design and not production tested, unless otherwise noted.)
PARAMETER
Supply Voltage
Supply Current
LOSEL Input High Voltage
LOSEL Input Low Voltage
SYMBOL
V
CC
I
CC
V
IH
V
IL
CONDITIONS
R2 = R5 = 600Ω
Total supply current, V
CC
= 3.3V
MIN
3.0
TYP
3.3
280
2
0.8
MAX
3.6
UNITS
V
mA
V
V
2
_______________________________________________________________________________________
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
RECOMMENDED AC OPERATING CONDITIONS
PARAMETER
RF Frequency
LO Frequency
SYMBOL
f
RF
f
LO
(Note 5)
(Note 5)
Using Mini-Circuits TC4-1W-17 4:1 transformer
as defined in the
Typical Application Circuit,
IF matching components affect the IF
frequency range (Note 5)
Using alternative Mini-Circuits TC4-1W-7A
4:1 transformer, IF matching components
affect the IF frequency range (Note 5)
LO Drive Level
P
LO
(Note 5)
CONDITIONS
MIN
700
900
TYP
MAX
1000
1300
UNITS
MHz
MHz
MAX19985A
100
500
MHz
IF Frequency
f
IF
50
-3
250
+3
dBm
+5.0V SUPPLY AC ELECTRICAL CHARACTERISTICS
(Typical
Application Circuit,
V
CC
= +4.75V to +5.25V, RF and LO ports are driven from 50Ω sources, P
LO
= -3dBm to +3dBm,
P
RF
= -5dBm, f
RF
= 700MHz to 1000MHz, f
LO
= 900MHz to 1200MHz, f
IF
= 200MHz, f
RF
< f
LO
, T
C
= -40°C to +85°C. Typical values
are at V
CC
= +5.0V, P
RF
= -5dBm, P
LO
= 0dBm, f
RF
=900MHz, f
LO
= 1100MHz, f
IF
= 200MHz, T
C
=+25°C, all parameters are guaran-
teed by design and characterization, unless otherwise noted.) (Note 6)
PARAMETER
SYMBOL
CONDITIONS
f
IF
= 200MHz, f
RF
= 824MHz to 915MHz,
T
C
= -40°C to +85°C
f
IF
= 200MHz, f
RF
= 824MHz to 915MHz,
T
C
= +25°C (Note 9)
Flatness over any one of three frequency
bands:
f
RF
= 824MHz to 849MHz,
f
RF
= 869MHz to 894MHz,
f
RF
= 880MHz to 915MHz (Note 9)
T
C
= -40°C to +85°C
T
C
= -40°C to +85°C
Noise Figure
Noise Figure Temperature
Coefficient
Noise Figure Under Blocking
Condition
NF
f
RF
= 850MHz, f
IF
= 200MHz,
P
LO
= 0dBm, T
C
= +25°C, V
CC
= +5.0V
T
C
= -40°C to +85°C
+8dBm blocker tone applied to RF port,
f
RF
= 900MHz, f
LO
= 1090MHz,
P
LO
= -3dBm, f
BLOCKER
= 800MHz,
V
CC
= +5.0V (Note 7)
T
C
= -40°C to +85°C
T
C
= +25°C (Note 9)
f
RF
= 824MHz to 915MHz,
f
RF1
- f
RF2
= 1MHz, f
IF
= 200MHz,
P
RF
= -5dBm/tone, T
C
= -40°C to +85°C
f
RF
= 824MHz to 915MHz,
f
RF1
- f
RF2
= 1MHz, f
IF
= 200MHz,
P
RF
= -5dBm/tone, T
C
= +25°C (Note 9)
10.0
11.0
22.5
MIN
7.0
7.7
TYP
8.7
8.7
MAX
10.2
dB
9.7
UNITS
Conversion Power Gain
G
C
Conversion Power Gain Variation
vs. Frequency
ΔG
C
0.15
0.3
dB
Gain Variation Over Temperature
TC
G
-0.012
9.2
9.0
0.018
11.5
10.3
dB/°C
dB
TC
NF
dB/°C
N
FB
18.8
22
dB
Input 1dB Compression Point
IP
1dB
12.6
12.6
25.5
dBm
Third-Order Input Intercept Point
IIP3
dBm
23.5
25.5
_______________________________________________________________________________________
3
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
MAX19985A
+5.0V SUPPLY AC ELECTRICAL CHARACTERISTICS (continued)
(Typical
Application Circuit,
V
CC
= +4.75V to +5.25V, RF and LO ports are driven from 50Ω sources, P
LO
= -3dBm to +3dBm,
P
RF
= -5dBm, f
RF
= 700MHz to 1000MHz, f
LO
= 900MHz to 1200MHz, f
IF
= 200MHz, f
RF
< f
LO
, T
C
= -40°C to +85°C. Typical values
are at V
CC
= +5.0V, P
RF
= -5dBm, P
LO
= 0dBm, f
RF
=900MHz, f
LO
= 1100MHz, f
IF
= 200MHz, T
C
=+25°C, all parameters are guaran-
teed by design and characterization, unless otherwise noted.) (Note 6)
PARAMETER
2LO-2RF Spur Rejection
SYMBOL
2x2
CONDITIONS
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 900MHz
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 933.3MHz
P
RF
= -10dBm
P
RF
= -5dBm
(Note 9)
P
RF
= -10dBm
P
RF
= -5dBm
(Note 9)
MIN
-63
-58
-65
-60
TYP
-76
-71
-78
-73
-40
-38
-35
-50
-25
-35
30
40
38
46
-20
-25
dBm
-22
-28
-15
-23
dBm
dBm
dBm
dB
dB
dBc
dBc
MAX
UNITS
3LO-3RF Spur Rejection
3x3
LO Leakage at RF Port
f
LO
= 900MHz to 1300MHz, P
LO
= +3dBm
(Note 10)
f
LO
= 900MHz to 1200MHz, P
LO
= +3dBm
(Note 10)
dBm
2LO Leakage at RF Port
f
LO
= 1200MHz to 1300MHz, P
LO
= +3dBm
(Note 10)
f
LO
= 900MHz to 1300MHz, P
LO
= +3dBm
(Note 10)
f
LO
= 900MHz to 1300MHz, P
LO
= +3dBm
(Note 9)
f
LO
= 900MHz to 1300MHz, P
LO
= +3dBm
(Note 10)
f
RF
= 824MHz to 915MHz (Note 10)
P
LO1
= +3dBm, P
LO2
= +3dBm,
f
LO1
= 900MHz, f
LO2
= 901MHz,
P
RF
= -5dBm (Notes 8, 10)
RFMAIN (RFDIV) converted power measured
at IFDIV (IFMAIN), relative to IFMAIN (IFDIV),
all unused ports terminated to 50Ω (Note 9)
50% of LOSEL to IF settled within 2 degrees
Z
RF
LO on and IF terminated into matched
impedance
Z
LO
RF and IF terminated into matched
impedance, LO port selected
3LO Leakage at RF Port
4LO Leakage at RF Port
LO Leakage at IF Port
RF-to-IF Isolation
LO-to-LO Isolation
Channel-to-Channel Isolation
LO Switching Time
RF Input Impedance
RF Input Return Loss
LO Input Impedance
40
48
50
50
20
50
20
1000
dB
ns
Ω
dB
Ω
LO Input Return Loss
RF and IF terminated into matched
impedance, LO port unselected
Z
IF
Nominal differential impedance at the IC’s
IF output
RF terminated in 50Ω; transformed to 50Ω
using external components shown in the
Typical Application Circuit
dB
20
200
Ω
IF Terminal Output Impedance
IF Return Loss
18
dB
4
_______________________________________________________________________________________
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
+3.3V SUPPLY AC ELECTRICAL CHARACTERISTICS
(Typical
Application Circuit,
RF and LO ports are driven from 50Ω sources. Typical values are at V
CC
= +3.3V, P
RF
= -5dBm,
P
LO
= 0dBm, f
RF
= 900MHz, f
LO
= 1100MHz, f
IF
= 200MHz, T
C
=+25°C, unless otherwise noted.) (Note 6)
PARAMETER
Conversion Power Gain
SYMBOL
G
C
Flatness over any one of three frequency
bands:
f
RF
= 824MHz to 849MHz,
f
RF
= 869MHz to 894MHz,
f
RF
= 880MHz to 915MHz
T
C
= -40°C to +85°C
CONDITIONS
MIN
TYP
8.7
MAX
UNITS
dB
MAX19985A
Conversion Power Gain Variation
vs. Frequency
ΔG
C
0.15
dB
Gain Variation Over Temperature
Noise Figure
Noise Figure Temperature
Coefficient
Input 1dB Compression Point
Third-Order Input Intercept Point
TC
G
NF
TC
NF
IP
1dB
IIP3
-0.012
9.0
dB/°C
dB
dB/°C
dBm
dBm
T
C
= -40°C to +85°C
0.018
10.6
f
RF1
= 900MHz, f
RF2
= 901MHz,
f
IF
= 200MHz, P
RF
= -5dBm/tone
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 900MHz
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 933.333MHz
P
RF
= -10dBm
P
RF
= -5dBm
P
RF
= -10dBm
P
RF
= -5dBm
24.7
-74.9
2LO-2RF Spur Rejection
2x2
dBc
-69.9
-78
dBc
-73
-40
-42
-34
38
45
dBm
dBm
dBm
dB
dB
3LO-3RF Spur Rejection
Maximum LO Leakage at RF Port
Maximum 2LO Leakage at RF Port
Maximum LO Leakage at IF Port
Minimum RF-to-IF Isolation
LO-to-LO Isolation
3x3
f
LO
= 900MHz to 1300MHz, P
LO
= +3dBm
f
LO
= 900MHz to 1300MHz, P
LO
= +3dBm
f
LO
= 900MHz to 1300MHz, P
LO
= +3dBm
f
RF
= 824MHz to 915MHz
P
LO1
= +3dBm, P
LO2
= +3dBm,
f
LO1
= 900MHz, f
LO2
= 901MHz (Note 8)
RFMAIN (RFDIV) converted power measured
at IFDIV (IFMAIN), relative to IFMAIN (IFDIV),
all unused ports terminated to 50Ω
50% of LOSEL to IF settled within 2 degrees
Z
RF
LO on and IF terminated into matched
impedance
Z
LO
RF and IF terminated into matched
impedance, LO port selected
Channel-to-Channel Isolation
LO Switching Time
RF Input Impedance
RF Input Return Loss
LO Input Impedance
48
50
50
21
50
31
dB
ns
Ω
dB
Ω
LO Input Return Loss
RF and IF terminated into matched
impedance, LO port unselected
dB
24
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5
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