MAXIM MAX19985A Technical data
General Description
The MAX19985A high-linearity, dual-channel, downconversion mixer is designed to provide approximately
8.7dB gain, +25.5dBm of IIP3, and 9.0dB of noise figure for 700MHz to 1000MHz diversity receiver applications. 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 compatible with the MAX19985A.
In addition to offering excellent linearity and noise performance, 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 differential IF output amplifiers. On-chip baluns are also integrated 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 VCC= +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 performance is guaranteed over the extended temperature
range of TC= -40°C to +85°C.
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
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/ReducedPerformance Mode
MAX19985A
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
________________________________________________________________
Maxim Integrated Products
1
19-4185; Rev 0; 8/08
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.
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.
+
Denotes a lead-free/RoHS-compliant package.
*
EP = Exposed pad.
T = Tape and reel.
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX19985AETX+
36 Thin QFN-EP*
MAX19985AETX+T
36 Thin QFN-EP*
-40°C to +85°C
-40°C to +85°C
MAX19985A
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
+3.3V SUPPLY DC ELECTRICAL CHARACTERISTICS
(
Typical Application Circuit
, VCC= 3.0V to 3.6V, TC= -40°C to +85°C. Typical values are at VCC= 3.3V, TC= +25°C, all parameters
are guaranteed by design and not production tested, 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.
Note 1: Based on junction temperature TJ= TC+ (θJCx VCCx ICC). 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
= TA+ (θJAx VCCx ICC). 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. TAis the ambient temperature of the device and PCB.
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
PARAMETER
CONDITIONS
UNITS
Supply Voltage V
CC
R2 = R5 = 600Ω 3.0 3.3 3.6 V
Supply Current I
CC
Total supply current, VCC = 3.3V
mA
LOSEL Input High Voltage V
IH
2V
LOSEL Input Low Voltage V
IL
0.8 V
+5.0V SUPPLY DC ELECTRICAL CHARACTERISTICS
(
Typical Application Circuit
, VCC= 4.75V to 5.25V, TC= -40°C to +85°C. Typical values are at VCC= 5.0V, TC= +25°C, all parame-
ters are production tested, unless otherwise noted.)
PARAMETER
CONDITIONS
UNITS
Supply Voltage V
CC
5
V
Supply Current I
CC
380 mA
LOSEL Input High Voltage V
IH
2V
LOSEL Input Low Voltage V
IL
0.8 V
LOSEL Input Current IIH, I
IL
-10
µA
SYMBOL
MIN TYP MAX
4.75
330
5.25
SYMBOL
+10
MIN TYP MAX
280
MAX19985A
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
_______________________________________________________________________________________ 3
RECOMMENDED AC OPERATING CONDITIONS
PARAMETER
CONDITIONS
UNITS
RF Frequency f
RF
(Note 5)
MHz
LO Frequency f
LO
(Note 5)
MHz
U si ng M i ni - C i r cui ts TC 4- 1W- 17 4:1 tr ansfor m er
as defined in the Typical Application Circuit,
IF matching components affect the IF
frequency range (Note 5)
500
IF Frequency f
IF
Using alternative Mini-Circuits TC4-1W-7A
4:1 transformer, IF matching components
affect the IF frequency range (Note 5)
50 250
MHz
LO Drive Level P
LO
(Note 5) -3 +3
dBm
+5.0V SUPPLY AC ELECTRICAL CHARACTERISTICS
(
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= 700MHz to 1000MHz, fLO= 900MHz to 1200MHz, fIF= 200MHz, fRF< fLO, TC= -40°C to +85°C. Typical values
are at V
CC
= +5.0V, PRF= -5dBm, P
LO
= 0dBm, fRF=900MHz, fLO= 1100MHz, f
IF
= 200MHz, TC=+25°C, all parameters are guaran-
teed by design and characterization, unless otherwise noted.) (Note 6)
PARAMETER
CONDITIONS
UNITS
fIF = 200MHz, fRF = 824MHz to 915MHz,
T
C
= -40°C to +85°C
7.0 8.7
Conversion Power Gain G
C
fIF = 200MHz, fRF = 824MHz to 915MHz,
T
C
= +25°C (Note 9)
7.7 8.7 9.7
dB
Conversion Power Gain Variation
vs. Frequency
ΔG
C
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)
0.3 dB
G ai n V ar i ati on Over Tem p er atur eTCGTC = -40°C to +85°C
dB/°C
TC = -40°C to +85°C 9.2
Noise Figure NF
f
RF
= 850MHz, fIF = 200MHz,
P
LO
= 0d Bm , TC = + 25°C , V
C C
= + 5.0V
9.0
dB
Noise Figure Temperature
Coefficient
TC
NF
TC = -40°C to +85°C
dB/°C
Noise Figure Under Blocking
Condition
N
FB
+8dBm blocker tone applied to RF port,
f
RF
= 900MHz, fLO = 1090MHz,
P
LO
= -3dBm, f
BLOCKER
= 800MHz,
V
CC
= +5.0V (Note 7)
22 dB
TC = -40°C to +85°C
Input 1dB Compression Point IP
1dB
TC = +25°C (Note 9)
dBm
fRF = 824MHz to 915MHz,
f
RF1
- f
RF2
= 1MHz, fIF = 200MHz,
P
RF
= -5dBm/tone, TC = -40°C to +85°C
Third-Order Input Intercept Point
IIP3
f
RF
= 824MHz to 915MHz,
f
RF1
- f
RF2
= 1MHz, fIF = 200MHz,
P
RF
= -5dBm/tone, TC = +25°C (Note 9)
dBm
SYMBOL
MIN TYP MAX
700 1000
900 1300
100
SYMBOL
MIN TYP MAX
10.2
10.0 12.6
11.0 12.6
22.5 25.5
23.5 25.5
0.15
-0.012
0.018
18.8
11.5
10.3
MAX19985A
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
4 _______________________________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
PRF = -10dBm -63 -76
2LO-2RF Spur Rejection 2 x 2
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 900MHz
P
RF
= -5dBm
(Note 9)
-58 -71
dBc
PRF = -10dBm -65 -78
3LO-3RF Spur Rejection 3 x 3
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 933.3MHz
P
RF
= -5dBm
(Note 9)
-60 -73
dBc
LO Leakage at RF Port
f
LO
= 900MHz to 1300MHz, PLO = +3dBm
(Note 10)
-40 -20
fLO = 900MHz to 1200MHz, PLO = +3dBm
(Note 10)
-38 -25
2LO Leakage at RF Port
f
L O
= 1200M H z to 1300M H z, P
L O
= + 3d Bm
(Note 10)
-35 -22
3LO Leakage at RF Port
f
LO
= 900MHz to 1300MHz, PLO = +3dBm
(Note 10)
-50 -28
4LO Leakage at RF Port
f
LO
= 900MHz to 1300MHz, PLO = +3dBm
(Note 9)
-25 -15
LO Leakage at IF Port
f
LO
= 900MHz to 1300MHz, PLO = +3dBm
(Note 10)
-35 -23
RF-to-IF Isolation fRF = 824MHz to 915MHz (Note 10) 30 38 dB
LO-to-LO Isolation
P
LO1
= +3dBm, P
LO2
= +3dBm,
f
LO1
= 900MHz, f
LO2
= 901MHz,
P
RF
= -5dBm (Notes 8, 10)
40 46 dB
Channel-to-Channel Isolation
RFM AIN ( RFD IV ) conver ted p ow er m easur ed
at IFD IV ( IFM AIN ) , r el ati ve to IFM AIN ( IFD IV ) ,
al l unused p or ts ter m i nated to 50Ω ( N ote 9)
40 48 dB
LO Switching Time 50% of LOS E L to IF settl ed w i thi n 2 d eg r ees 50
ns
RF Input Impedance Z
RF
50 Ω
RF Input Return Loss
LO on and IF terminated into matched
impedance
20 dB
LO Input Impedance Z
LO
50 Ω
RF and IF terminated into matched
impedance, LO port selected
20
LO Input Return Loss
RF and IF terminated into matched
impedance, LO port unselected
20
dB
IF Terminal Output Impedance Z
IF
Nominal differential impedance at the IC’s
IF output
Ω
IF Return Loss
RF terminated in 50Ω; transformed to 50Ω
using external components shown in the
Typical Application Circuit
18 dB
+5.0V SUPPLY AC ELECTRICAL CHARACTERISTICS (continued)
(
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= 700MHz to 1000MHz, fLO= 900MHz to 1200MHz, fIF= 200MHz, fRF< fLO, TC= -40°C to +85°C. Typical values
are at V
CC
= +5.0V, PRF= -5dBm, P
LO
= 0dBm, fRF=900MHz, fLO= 1100MHz, f
IF
= 200MHz, TC=+25°C, all parameters are guaran-
teed by design and characterization, unless otherwise noted.) (Note 6)
200
dBm
dBm
dBm
dBm
dBm
1000
MAX19985A
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
_______________________________________________________________________________________ 5
+3.3V SUPPLY AC ELECTRICAL CHARACTERISTICS
(
Typical Application Circuit
, RF and LO ports are driven from 50Ω sources. Typical values are at VCC= +3.3V, PRF= -5dBm,
P
LO
= 0dBm, fRF= 900MHz, fLO= 1100MHz, fIF= 200MHz, TC=+25°C, unless otherwise noted.) (Note 6)
PARAMETER
CONDITIONS
UNITS
Conversion Power Gain G
C
8.7 dB
Conversion Power Gain Variation
vs. Frequency
ΔG
C
Flatness over any one of three frequency
bands:
f
RF
= 824MHz to 849MHz,
f
RF
= 869MHz to 894MHz,
f
RF
= 880MHz to 915MHz
dB
G ai n V ar i ati on Over Tem p er atur eTCGTC = -40°C to +85°C
dB/°C
Noise Figure NF 9.0 dB
Noise Figure Temperature
Coefficient
TC
NF
TC = -40°C to +85°C
dB/°C
Input 1dB Compression Point IP
1dB
dBm
Third-Order Input Intercept Point
IIP3
f
RF1
= 900MHz, f
RF2
= 901MHz,
f
IF
= 200MHz, PRF = -5dBm/tone
dBm
PRF = -10dBm
2LO-2RF Spur Rejection 2 x 2
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 900MHz
P
RF
= -5dBm
dBc
P
RF
= -10dBm -78
3LO-3RF Spur Rejection 3 x 3
f
RF
= 800MHz,
f
LO
= 1000MHz,
f
SPUR
= 933.333MHz
P
RF
= -5dBm -73
dBc
Maximum LO Leakage at RF Port
fLO = 900MHz to 1300MHz, PLO = +3dBm -40
dBm
M axi m um 2LO Leakag e at RF P or t
fLO = 900MHz to 1300MHz, PLO = +3dBm -42
dBm
Maximum LO Leakage at IF Port
fLO = 900MHz to 1300MHz, PLO = +3dBm -34
dBm
Minimum RF-to-IF Isolation fRF = 824MHz to 915MHz 38 dB
LO-to-LO Isolation
P
LO1
= +3dBm, P
LO2
= +3dBm,
f
LO1
= 900MHz, f
LO2
= 901MHz (Note 8)
45 dB
Channel-to-Channel Isolation
RFM AIN ( RFD IV ) conver ted p ow er m easur ed
at IFD IV ( IFM AIN ) , r el ati ve to IFM AIN ( IFD IV ) ,
al l unused p or ts ter m i nated to 50Ω
48 dB
LO Switching Time 50% of LOS E L to IF settl ed w i thi n 2 d eg r ees 50 ns
RF Input Impedance Z
RF
50 Ω
RF Input Return Loss
LO on and IF terminated into matched
impedance
21 dB
LO Input Impedance Z
LO
50 Ω
RF and IF terminated into matched
impedance, LO port selected
31
LO Input Return Loss
RF and IF terminated into matched
impedance, LO port unselected
24
dB
SYMBOL
MIN TYP MAX
0.15
-0.012
0.018
10.6
24.7
-74.9
-69.9
MAX19985A
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
6 _______________________________________________________________________________________
Note 5: Not production tested. Operation outside this range is possible, but with degraded performance of some parameters. See
the
Typical Operating Characteristics
. Performance is optimized for RF frequencies of 824MHz to 915MHz.
Note 6: All limits reflect losses of external components. Output measurements taken at IF outputs of
Typical Application Circuit
.
Note 7: 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 the Application Note 2021:
Specifications and
Measurement of Local Oscillator Noise in Integrated Circuit Base Station Mixers
.
Note 8: Measured at IF port at IF frequency. LOSEL may be in any logic state.
Note 9: Limited production testing.
Note 10: Guaranteed by production testing.
+3.3V SUPPLY AC ELECTRICAL CHARACTERISTICS (continued)
(
Typical Application Circuit
, RF and LO ports are driven from 50Ω sources. Typical values are at VCC= +3.3V, PRF= -5dBm,
P
LO
= 0dBm, fRF= 900MHz, fLO= 1100MHz, fIF= 200MHz, TC=+25°C, unless otherwise noted.) (Note 6)
PARAMETER
CONDITIONS
IF Terminal Output Impedance Z
IF
Nominal differential impedance at the IC’s
IF output
Ω
IF Output Return Loss
RF terminated in 50Ω; transformed to 50Ω
using external components shown in the
Typical Application Circuit
17 dB
SYMBOL
MIN TYP MAX UNITS
200
MAX19985A
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
_______________________________________________________________________________________ 7
Typical Operating Characteristics
(
Typical Application Circuit
, VCC= +5.0V, PLO= 0dBm, PRF= -5dBm, LO is high-side injected for a 200MHz IF, TC=+25°C, unless
otherwise noted.)
CONVERSION GAIN vs. RF FREQUENCY
11
TC = -30°C
10
9
8
CONVERSION GAIN (dB)
TC = +85°C
7
6
700 1000
TC = +25°C
RF FREQUENCY (MHz)
INPUT IP3 vs. RF FREQUENCY
27
26
TC = +85°C
CONVERSION GAIN vs. RF FREQUENCY
11
10
9
8
CONVERSION GAIN (dB)
7
6
700 1000
VCC = 4.75V, 5.0V, 5.25V
900800
RF FREQUENCY (MHz)
INPUT IP3 vs. RF FREQUENCY
27
PRF = -5dBm/TONE
26
VCC = 5.25V
900800
PRF = -5dBm/TONE
11
10
MAX19985A toc01
9
8
CONVERSION GAIN (dB)
7
6
27
26
MAX19985A toc04
CONVERSION GAIN vs. RF FREQUENCY
PLO = -3dBm, 0dBm, +3dBm
700 1000
RF FREQUENCY (MHz)
900800
INPUT IP3 vs. RF FREQUENCY
PRF = -5dBm/TONE
MAX19985A toc02
MAX19985A toc05
MAX19985A toc03
MAX19985A toc06
25
24
INPUT IP3 (dBm)
TC = -30°C
23
22
700 1000
TC = +25°C
900800
RF FREQUENCY (MHz)
NOISE FIGURE vs. RF FREQUENCY
12
11
10
9
8
NOISE FIGURE (dB)
7
TC = -30°C
6
5
700 1000
TC = +85°C
TC = +25°C
900800
RF FREQUENCY (MHz)
INPUT IP3 (dBm)
MAX19985A toc07
NOISE FIGURE (dB)
25
24
PLO = +3dBm, 0dBm
23
22
700 1000
RF FREQUENCY (MHz)
PLO = -3dBm
900800
NOISE FIGURE vs. RF FREQUENCY
12
11
10
9
8
7
6
5
PLO = -3dBm, 0dBm, +3dBm
700 1000
RF FREQUENCY (MHz)
900800
INPUT IP3 (dBm)
MAX19985A toc08
NOISE FIGURE (dB)
25
24
VCC = 4.75V
23
22
700 1000
RF FREQUENCY (MHz)
VCC = 5.0V
900800
NOISE FIGURE vs. RF FREQUENCY
12
11
10
9
8
7
6
5
700 1000
VCC = 4.75V, 5.0V, 5.25V
900800
RF FREQUENCY (MHz)
MAX19985A toc09
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