General Description
The MAX9994 high-linearity downconversion mixer pro-
vides 8.3dB gain, +26.2dBm IIP3, and 9.7dB NF for
1400MHz to 2200MHz UMTS/WCDMA, DCS, and PCS
base-station receiver applications. With a wide LO range
of 1400MHz to 2000MHz, the MAX9994 can be used in
either high-side or low-side LO injection architectures,
depending on the RF band of interest. Higher LO appli-
cations are supported by the MAX9996, which is pin-pin
and functionally compatible with the MAX9994.
In addition to offering excellent linearity and noise per-
formance, the MAX9994 also yields a high level of com-
ponent integration. This device includes a double-
balanced passive mixer core, an IF amplifier, a dual-
input LO selectable switch, and an LO buffer. On-chip
baluns are also integrated to allow for single-ended RF
and LO inputs. The MAX9994 requires a nominal LO
drive of 0dBm, and supply current is guaranteed to be
below 235mA.
The MAX9994/MAX9996 are pin compatible with the
MAX9984/MAX9986 815MHz to 995MHz mixers, mak-
ing this entire family of downconverters ideal for appli-
cations where a common PC board layout is used for
both frequency bands. The MAX9994 is also functional-
ly compatible with the MAX9993.
The MAX9994 is available in a compact, 20-pin, thin
QFN package (5mm x 5mm) with an exposed pad.
Electrical performance is guaranteed over the extended
-40°C to +85°C temperature range.
Applications
UMTS/LTE Base Stations
TD-SCDMA/TD-LTE Base Stations
DCS1800/PCS1900 EDGE Base Stations
cdmaOne™ and cdma2000®Base Stations
PHS/PAS Base Stations
Predistortion Receivers
Fixed Broadband Wireless Access
Wireless Local Loop
Private Mobile Radios
Military Systems
Microwave Links
Digital and Spread-Spectrum Communication
Systems
Features
♦1400MHz to 2200MHz RF Frequency Range
♦1400MHz to 2000MHz LO Frequency Range
(MAX9994)
♦1900MHz to 2400MHz LO Frequency Range
(MAX9996)
♦40MHz to 350MHz IF Frequency Range
♦8.3dB Conversion Gain
♦+26.2dBm Input IP3
♦+12.6dBm Input 1dB Compression Point
♦9.7dB Noise Figure
♦67dBc 2RF - 2LO Spurious Rejection at
PRF = -10dBm
♦Integrated LO Buffer
♦Integrated RF and LO Baluns for Single-Ended
Inputs
♦Low -3dBm to +3dBm LO Drive
♦Built-In SPDT LO Switch with 45dB LO1 to LO2
Isolation and 50ns Switching Time
♦Pin Compatible with the MAX9984/MAX9986
815MHz to 995MHz Mixers
♦Functionally Compatible with the MAX9993
♦External Current-Setting Resistors Provide Option
for Operating Mixer in Reduced Power/Reduced
Performance Mode
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
________________________________________________________________
Maxim Integrated Products
1
Pin Configuration/Functional Diagram and Typical
Application Circuit appear at end of data sheet.
19-3435; Rev 1; 12/10
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.
EVALUATION KIT
AVAILABLE
Ordering Information
**
EP = Exposed pad.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
PART TEMP RANGE PIN-PACKAGE
MAX9994ETP+ -40°C to +85°C
20 Thin QFN-EP**
5mm 5mm
bulk
MAX9994ETP+T -40°C to +85°C
20 Thin QFN-EP**
5mm 5mm
T/R
cdma2000 is a registered trademark of Telecommunications
Industry Association.
cdmaOne is a trademark of CDMA Development Group.
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(
Typical Application Circuit
, VCC = +4.75V to +5.25V, no RF signal applied, IF+ and IF- outputs pulled up to VCC through inductive
chokes, R1= 806Ω, R2= 549Ω, TC= -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +5V, 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.
VCC to GND...........................................................-0.3V to +5.5V
IF+, IF-, LOBIAS, LOSEL, IFBIAS to GND...-0.3V to (VCC + 0.3V)
TAP ........................................................................-0.3V to +1.4V
LO1, LO2, LEXT to GND........................................-0.3V to +0.3V
RF, LO1, LO2 Input Power .............................................+12dBm
RF (RF is DC shorted to GND through a balun) .................50mA
Continuous Power Dissipation (TA= +70°C)
20-Pin Thin QFN-EP (derate 20mW/°C above +70°C)..............1.8W
θJA (Note 1) ...................................................................+38°C/W
θJC (Note 1) .....................................................................+8°C/W
Operating Temperature Range (Note 2).....TC= -40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering 10s) ..................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Note 1: 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 2: TCis the temperature on the exposed pad of the package.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage VCC 4.75 5.00 5.25 V
Supply Current ICC 206 235 mA
LO_SEL Input Logic-Low VIL 0.8 V
LO_SEL Input Logic-High VIH 2V
RECOMMENDED AC OPERATING CONDITIONS
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
RF Frequency Range fRF (Note 3) 1400 2200 MHz
LO Frequency Range fLO (Note 3) 1400 2000 MHz
IF Frequency Range fIF (Note 3) 40 350 MHz
LO Drive Level PLO (Note 3) -3 +3 dBm
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
_______________________________________________________________________________________ 3
AC ELECTRICAL CHARACTERISTICS—fRF = 1700MHz TO 2200MHz, LOW-SIDE LO INJECTION
(
Typical Application Circuit
, VCC = +4.75V to +5.25V, RF and LO ports are driven from 50Ωsources, PLO = -3dBm to +3dBm,
PRF = -5dBm, fRF = 1700MHz to 2200MHz, fLO = 1400MHz to 2000MHz, fIF = 200MHz, fRF > fLO, TC= -40°C to +85°C, unless other-
wise noted. Typical values are at VCC = +5V, PRF = -5dBm, PLO = 0dBm, fRF = 1900MHz, fLO = 1700MHz, fIF = 200MHz,
TC= +25°C, unless otherwise noted.) (Notes 4, 5)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Conversion Gain GC P
RF < +2dBm, TA = +25°C (Note 6) 7.2 8.3 9.2 dB
Gain Variation Over Temperature TC = -40°C to +85°C±0.75 dB
Input Compression Point P1dB (Note 7) 12.6 dBm
Input Third-Order Intercept Point
(Note 6) IIP3
Two tones:
fRF1 = 2000MHz, fRF2 = 2001MHz,
PRF = -5dBm/tone, fLO = 1800MHz,
PLO = 0dBm, TA = +25°C
23.5 26.2 dBm
Input IP3 Variation Over
Temperature T
C = -40°C to +85°C±0.5 dB
Noise Figure NF Single sideband 9.7 dB
Noise Figure Under-Blocking PRF = 5dBm, fRF = 2000MHz,
fLO = 1810MHz, fblock = 2100MHz (Note 8) 19 dB
LO Drive -3 +3 dBm
PRF = -10dBm 67
2 x 2 2RF - 2LO PRF = -5dBm 62
PRF = -10dBm 82
Spurious Response at IF
3 x 3 3RF - 3LO PRF = -5dBm 72
dBc
LO2 selected,
1500MHz < fLO < 1700MHz 40 52
LO1 to LO2 Isolation
(Note 4) LO1 selected,
1500MHz < fLO < 1700MHz 40 45
dB
Maximum LO Leakage at RF
Port P
LO = +3dBm -17 dBm
Maximum LO Leakage at IF Port PLO = +3dBm -30 dBm
Minimum RF-to-IF Isolation 35 dB
LO Switching Time 50% of LOSEL to IF settled to within 2° 50 ns
RF Port Return Loss 21 dB
LO1/2 port selected,
LO2/1 and IF terminated 16
LO Port Return Loss LO1/2 port unselected,
LO2/1 and IF terminated 26
dB
IF Port Return Loss LO driven at 0dBm, RF terminated into
50, differential 200 20 dB
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
4 _______________________________________________________________________________________
Note 3: Operation outside this range is possible, but with degraded performance of some parameters.
Note 4: Guaranteed by design and characterization.
Note 5: All limits include external component losses. Output measurements taken at IF output of the
Typical Application Circuit
.
Note 6: Production tested.
Note 7: Compression point characterized. It is advisable not to operate continuously the mixer RF input above +12dBm.
Note 8: 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 Application Note 2021:
Specifications and
Measurement of Local Oscillator Noise in Integrated Circuit Base Station Mixers
.
AC ELECTRICAL CHARACTERISTICS—fRF = 1455MHz, HIGH-SIDE LO INJECTION
(
Typical Application Circuit
, RF and LO ports are driven from 50Ωsources, fRF < fLO, VCC = +5V, PRF = -5dBm, PLO = 0dBm,
fRF = 1455MHz, fLO = 1625MHz, fIF = 170MHz, TC= +25°C, LO2 is selected, unless otherwise noted.) (Note 5)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Conversion Gain GC 8.8 dB
Input Third-Order Intercept Point IIP3
Two tones:
fRF1 = 1455MHz, fRF2 = 1456MHz,
PRF = -5dBm/tone
25.6 dBm
Input Compression Point
(Note 7) IP1dB 12.7 dBm
PRF = -10dBm 71.4
2LO - 2RF Spurious Response 2 x 2 PRF = -5dBm 66.4 dBc
LO-to-IF Leakage LOSEL = LO2 -30.2 dBm
AC ELECTRICAL CHARACTERISTICS—fRF = 1500MHz, HIGH-SIDE LO INJECTION
(
Typical Application Circuit
, RF and LO ports are driven from 50Ωsources, fRF < fLO, VCC = +5V, PRF = -5dBm, PLO = 0dBm,
fRF = 1500MHz, fLO = 1650MHz, fIF = 150MHz, TC= +25°C, LO1 is selected, unless otherwise noted.) (Note 5)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Conversion Gain GC 8.9 dB
Input Third-Order Intercept Point IIP3
Two tones:
fRF1 = 1500MHz, fRF2 = 1501MHz,
PRF = -5dBm/tone
25.5 dBm
Input Compression Point
(Note 7) IP1dB 12.5 dBm
PRF = -10dBm 70.4
2LO - 2RF Spurious Response 2 x 2 PRF = -5dBm 65.4 dBc
LO-to-IF Leakage -33.2 dBm
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
_______________________________________________________________________________________
5
6
7
9
8
10
11
1500 18001650 1950 2100 2250 2400
CONVERSION GAIN vs. RF FREQUENCY
MAX9994 toc01
RF FREQUENCY (MHz)
CONVERSION GAIN (dB)
TC = +85°CTC = +25°C
TC = -25°C
6
7
9
8
10
11
1500 18001650 1950 2100 2250 2400
CONVERSION GAIN vs. RF FREQUENCY
MAX9994 toc02
RF FREQUENCY (MHz)
CONVERSION GAIN (dB)
PLO = -3dBm, 0dBm, +3dBm
6
7
9
8
10
11
1500 18001650 1950 2100 2250 2400
CONVERSION GAIN vs. RF FREQUENCY
MAX9994 toc03
RF FREQUENCY (MHz)
CONVERSION GAIN (dB)
VCC = 4.75V, 5.0V, 5.25V
21
23
22
25
24
27
26
28
1500 1800 19501650 2100 2250 2400
INPUT IP3 vs. RF FREQUENCY
MAX9994 toc04
RF FREQUENCY (MHz)
INPUT IP3 (dBm)
TC = +25°C
TC = -25°C
TC = +85°C
23
22
25
24
27
26
28
1500 1800 19501650 2100 2250 2400
INPUT IP3 vs. RF FREQUENCY
MAX9994 toc05
RF FREQUENCY (MHz)
INPUT IP3 (dBm)
PLO = +3dBm
PLO = -3dBm, 0dBm
23
22
25
24
27
26
28
1500 1800 19501650 2100 2250 2400
INPUT IP3 vs. RF FREQUENCY
MAX9994 toc06
RF FREQUENCY (MHz)
INPUT IP3 (dBm)
VCC = 4.75V
VCC = 5.0V, 5.25V
7
6
9
8
11
12
10
13
1500 1800 19501650 2100 2250 2400
NOISE FIGURE vs. RF FREQUENCY
MAX9994 toc07
RF FREQUENCY (MHz)
NOISE FIGURE (dB)
TC = +85°C
TC = +25°C
TC = -25°C
7
8
10
11
9
12
1500 1800 19501650 2100 2250 2400
NOISE FIGURE vs. RF FREQUENCY
MAX9994 toc08
RF FREQUENCY (MHz)
NOISE FIGURE (dB)
PLO = +3dBm
PLO = -3dBm
PLO = 0dBm
7
8
10
11
9
12
1500 1800 19501650 2100 2250 2400
NOISE FIGURE vs. RF FREQUENCY
MAX9994 toc09
RF FREQUENCY (MHz)
NOISE FIGURE (dB)
VCC = 5.25V
VCC = 5.0V
VCC = 4.75V
Typical Operating Characteristics
(MAX9994
Typical Application Circuit
, VCC = +5.0V, PLO = 0dBm, PRF = -5dBm, fRF = 1700MHz to 2200MHz, LO is Low-Side
Injected for a 200MHz IF, unless otherwise noted.)
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
6 _______________________________________________________________________________________
45
50
70
80
60
65
75
55
85
1500 1800 19501650 2100 2250 2400
2RF - 2LO RESPONSE vs. RF FREQUENCY
MAX9994 toc10
RF FREQUENCY (MHz)
2RF - 2LO RESPONSE (dBc)
TC = +25°C
TC = -25°C
TC = +85°C
PRF = -5dBm
45
50
70
80
60
65
75
55
85
1500 1800 19501650 2100 2250 2400
2RF - 2LO RESPONSE vs. RF FREQUENCY
MAX9994 toc11
RF FREQUENCY (MHz)
2RF - 2LO RESPONSE (dBc)
PLO = +3dBm
PLO = -3dBm
PLO = 0dBm
PRF = -5dBm
45
50
70
80
60
65
75
55
90
85
1500 1800 19501650 2100 2250 2400
2RF - 2LO RESPONSE vs. RF FREQUENCY
MAX9994 toc12
RF FREQUENCY (MHz)
2RF - 2LO RESPONSE (dBc)
PRF = -5dBm
VCC = 4.75V, 5.0V, 5.25V
70
80
60
65
75
55
95
90
85
1500 1800 19501650 2100 2250 2400
3RF - 3LO RESPONSE vs. RF FREQUENCY
MAX9994 toc13
RF FREQUENCY (MHz)
3RF - 3LO RESPONSE (dBc)
PRF = -5dBm
TC = +25°C
TC = +85°C
TC = -25°C
70
80
60
65
75
55
95
90
85
1500 1800 19501650 2100 2250 2400
3RF - 3LO RESPONSE vs. RF FREQUENCY
MAX9994 toc14
RF FREQUENCY (MHz)
3RF - 3LO RESPONSE (dBc)
PRF = -5dBm
PLO = -3dBm, 0dBm, +3dBm
70
80
60
65
75
55
95
90
85
1500 1800 19501650 2100 2250 2400
3RF - 3LO RESPONSE vs. RF FREQUENCY
MAX9994 toc15
RF FREQUENCY (MHz)
3RF - 3LO RESPONSE (dBc)
PRF = -5dBm
VCC = 5.25V VCC = 5.0V
VCC = 4.75V
13
11
12
14
10
15
1500 1800 19501650 2100 2250 2400
INPUT P1dB vs. RF FREQUENCY
MAX9994 toc16
RF FREQUENCY (MHz)
INPUT P1dB (dBm)
TC = +85°C
TC = -25°CTC = +25°C
13
11
12
14
10
15
1500 1800 19501650 2100 2250 2400
INPUT P1dB vs. RF FREQUENCY
MAX9994 toc17
RF FREQUENCY (MHz)
INPUT P1dB (dBm)
PLO = -3dBm, 0dBm, +3dBm
13
11
12
14
10
15
1500 1800 19501650 2100 2250 2400
INPUT P1dB vs. RF FREQUENCY
MAX9994 toc18
RF FREQUENCY (MHz)
INPUT P1dB (dBm)
VCC = 5.25V
VCC = 5.0V
VCC = 4.75V
Typical Operating Characteristics (continued)
(MAX9994
Typical Application Circuit
, VCC = +5.0V, PLO = 0dBm, PRF = -5dBm, fRF = 1700MHz to 2200MHz, LO is Low-Side
Injected for a 200MHz IF, unless otherwise noted.)
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
_______________________________________________________________________________________
7
50
40
45
35
55
1300 1600 17501450 1900 2050 2200
LO SWITCH ISOLATION
vs. LO FREQUENCY
MAX9994 toc19
LO FREQUENCY (MHz)
LO SWITCH ISOLATION (dB)
TC = -25°C
TC = +25°C
TC = +85°C
50
40
45
35
55
1300 1600 17501450 1900 2050 2200
LO SWITCH ISOLATION
vs. LO FREQUENCY
MAX9994 toc20
LO FREQUENCY (MHz)
LO SWITCH ISOLATION (dB)
PLO = +3dBm
PLO = -3dBm
PLO = 0dBm
50
40
45
35
55
1300 1600 17501450 1900 2050 2200
LO SWITCH ISOLATION
vs. LO FREQUENCY
MAX9994 toc21
LO FREQUENCY (MHz)
LO SWITCH ISOLATION (dB)
VCC = 4.75V, 5.0V, 5.25V
-30
-50
-40
-60
-20
-35
-55
-45
-25
1300 1600 17501450 1900 2050 2200
LO LEAKAGE AT IF PORT
vs. LO FREQUENCY
MAX9994 toc22
LO FREQUENCY (MHz)
LO LEAKAGE (dBm)
TC = -25°C
TC = +85°C
TC = +25°C
-30
-50
-40
-60
-20
-35
-55
-45
-25
1300 1600 17501450 1900 2050 2200
LO LEAKAGE AT IF PORT
vs. LO FREQUENCY
MAX9994 toc23
LO FREQUENCY (MHz)
LO LEAKAGE (dBm)
PLO = -3dBm
PLO = 0dBm
PLO = +3dBm
-30
-50
-40
-20
-35
-55
-45
-25
1300 1600 17501450 1900 2050 2200
LO LEAKAGE AT IF PORT
vs. LO FREQUENCY
MAX9994 toc24
LO FREQUENCY (MHz)
LO LEAKAGE (dBm)
VCC = 5.25V
VCC = 5.0V
VCC = 4.75V
-20
-30
-10
-25
-15
1300 1600 17501450 1900 2050 2200
LO LEAKAGE AT RF PORT
vs. LO FREQUENCY
MAX9994 toc25
LO FREQUENCY (MHz)
LO LEAKAGE AT RF PORT (dBm)
TC = -25°C, +25°C, +85°C
-20
-30
-10
-25
-15
1300 1600 17501450 1900 2050 2200
LO LEAKAGE AT RF PORT
vs. LO FREQUENCY
MAX9994 toc26
LO FREQUENCY (MHz)
LO LEAKAGE AT RF PORT (dBm)
PLO = -3dBm, 0dBm, +3dBm
-20
-30
-10
-25
-15
1300 1600 17501450 1900 2050 2200
LO LEAKAGE AT RF PORT
vs. LO FREQUENCY
MAX9994 toc27
LO FREQUENCY (MHz)
LO LEAKAGE AT RF PORT (dBm)
VCC = 5.25V
VCC = 5.0V
VCC = 4.75V
Typical Operating Characteristics (continued)
(MAX9994
Typical Application Circuit
, VCC = +5.0V, PLO = 0dBm, PRF = -5dBm, fRF = 1700MHz to 2200MHz, LO is Low-Side
Injected for a 200MHz IF, unless otherwise noted.)
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
8 _______________________________________________________________________________________
40
30
60
35
50
45
55
1500 1800 19501650 2100 2250 2400
RF-TO-IF ISOLATION
vs. RF FREQUENCY
MAX9994 toc28
RF FREQUENCY (MHz)
RF-TO-IF ISOLATION (dB)
TC = +85°C
TC = +25°C
TC = -25°C
40
30
60
35
50
45
55
1500 1800 19501650 2100 2250 2400
RF-TO-IF ISOLATION
vs. RF FREQUENCY
MAX9994 toc29
RF FREQUENCY (MHz)
RF-TO-IF ISOLATION (dB)
PLO = +3dBm
PLO = 0dBm
PLO = -3dBm
40
30
60
35
50
45
55
1500 1800 19501650 2100 2250 2400
RF-TO-IF ISOLATION
vs. RF FREQUENCY
MAX9994 toc30
RF FREQUENCY (MHz)
RF-TO-IF ISOLATION (dB)
VCC = 5.25V
VCC = 5.0V
VCC = 4.75V
30
40
0
35
20
25
10
15
5
1500 1800 19501650 2100 2250 2400
RF PORT RETURN LOSS
vs. RF FREQUENCY
MAX9994 toc31
RF FREQUENCY (MHz)
RF PORT RETURN LOSS (dB)
PLO = -3dBm, 0dBm, +3dBm
30
50
0
40
45
35
20
25
10
15
5
50 150 200100 250 300 350
IF PORT RETURN LOSS
vs. IF FREQUENCY
MAX9994 toc32
IF FREQUENCY (MHz)
IF PORT RETURN LOSS (dB)
VCC = 5.25V
VCC = 5.0V
VCC = 4.75V
30
0
40
35
20
25
10
15
5
1300 1500 1700 1900 2100 2300
LO SELECTED RETURN LOSS
vs. LO FREQUENCY
MAX9994 toc33
LO FREQUENCY (MHz)
LO SELECTED RETURN LOSS (dB)
PLO = +3dBm
PLO = -3dBm
PLO = 0dBm
30
0
40
35
20
25
10
15
5
1300 1500 1700 1900 2100 2300
LO UNSELECTED RETURN LOSS
vs. LO FREQUENCY
MAX9994 toc34
LO FREQUENCY (MHz)
LO UNSELECTED RETURN LOSS (dB)
PLO = -3dBm, 0dBm, +3dBm 200
240
180
190
220
230
210
-30 -10 10 30 50 70 90
SUPPLY CURRENT
vs. TEMPERATURE (TC)
MAX9994 toc35
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
VCC = 5.25V
VCC = 5.0V VCC = 4.75V
Typical Operating Characteristics (continued)
(MAX9994
Typical Application Circuit
, VCC = +5.0V, PLO = 0dBm, PRF = -5dBm, fRF = 1700MHz to 2200MHz, LO is Low-Side
Injected for a 200MHz IF, unless otherwise noted.)
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
_______________________________________________________________________________________
9
CONVERSION GAIN vs. FREQUENCY
MAX9994 toc36
RF FREQUENCY (MHz)
CONVERSION GAIN (dB)
146014551450
8
9
10
7
1445 1465
fIF VARIES WITH fRF
INPUT IP3 vs. RF FREQUENCY
MAX9994 toc37
RF FREQUENCY (MHz)
INPUT IP3 (dBm)
146014551450
25
26
27
24
1445 1465
fIF VARIES WITH fRF
PRF = -5dBm/TONE
2LO - 2RF RESPONSE vs. RF FREQUENCY
MAX9994 toc38
RF FREQUENCY (MHz)
2LO - 2RF RESPONSE (dBc)
146014551450
60
70
80
50
1445 1465
fIF FREQ VARIES WITH fRF
PRF = -5dBm
INPUT P1dB vs. FREQUENCY
MAX9994 toc39
RF FREQUENCY (MHz)
P1dB (dBm)
146014551450
12
13
14
11
1445 1465
fIF FREQ VARIES WITH fRF
LO LEAKAGE AT IF PORT
vs. LO FREQUENCY
MAX9994 toc40
LO FREQUENCY (MHz)
LO LEAKAGE AT IF PORT (dBm)
1600 1700
-40
-30
-20
-50
1500 1800
Typical Operating Characteristics (continued)
(MAX9994
Typical Application Circuit
, VCC = +5V, PLO = 0dBm, LO2 selected, PRF = -5dBm, fRF = 1400MHz to 1700MHz, LO is
High-Side Injected for a 170MHz IF, unless otherwise noted.)
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
10 ______________________________________________________________________________________
CONVERSION GAIN vs. FREQUENCY
MAX9994 toc41
RF FREQUENCY (MHz)
CONVERSION GAIN (dB)
1479 1529
8
9
10
7
1429 1579
fIF VARIES WITH fRF
INPUT IP3 vs. RF FREQUENCY
MAX9994 toc42
RF FREQUENCY (MHz)
INPUT IP3 (dBm)
1501 1506
25
26
27
24
1496 1511
fIF VARIES WITH fRF
PRF = -5dBm/TONE
2LO - 2RF RESPONSE vs. RF FREQUENCY
MAX9994 toc43
RF FREQUENCY (MHz)
2LO - 2RF RESPONSE (dBc)
1501 1506
60
70
80
50
1496 1511
fIF VARIES WITH fRF
PRF = -5dBm
INPUT P1dB vs. RF FREQUENCY
MAX9994 toc44
RF FREQUENCY (MHz)
P1dB (dBm)
1501 1506
12
13
14
11
1496 1511
fIF VARIES WITH fRF
LO LEAKAGE AT IF PORT
vs. LO FREQUENCY
MAX9994 toc45
LO FREQUENCY (MHz)
LO LEAKAGE AT IF PORT (dBm)
1600 1700
-40
-30
-20
-50
1500 1800
Typical Operating Characteristics (continued)
(MAX9994
Typical Application Circuit
, VCC = +5V, PLO = 0dBm, LO1 selected, PRF = -5dBm, fRF = 1400MHz to 1700MHz, LO is
High-Side Injected for a 150MHz IF, unless otherwise noted.)
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
______________________________________________________________________________________ 11
Detailed Description
The MAX9994 high-linearity downconversion mixer pro-
vides 8.3dB of conversion gain and 26.2dBm of IIP3,
with a typical 9.7dB noise figure. The integrated baluns
and matching circuitry allow for 50Ωsingle-ended inter-
faces to the RF and the two LO ports. A single-pole,
double-throw (SPDT) switch provides 50ns switching
time between the two LO inputs with 45dB of LO-to-LO
isolation. Furthermore, the integrated LO buffer pro-
vides a high drive level to the mixer core, reducing the
LO drive required at the MAX9994’s inputs to a range
of -3dBm to +3dBm. The IF port incorporates a differ-
ential output, which is ideal for providing enhanced IIP2
performance.
Specifications are guaranteed over broad frequency
ranges to allow for use in WCDMA, TD-SCDMA, LTE,
TD-LTE, cdma2000, and 2G/2.5G/3G DCS1800 and
PCS1900 base stations. The MAX9994 is specified to
operate over a 1400MHz to 2200MHz RF frequency
range, a 1400MHz to 2000MHz LO frequency range,
and a 40MHz to 350MHz IF frequency range. Operation
beyond these ranges is possible; see the
Typical
Operating Characteristics
for additional details.
With a wide LO range of 1400MHz to 2000MHz, the
MAX9994 can be used in either high-side or low-side
LO injection architectures, depending on the RF band
of interest. Higher LO applications are supported by
the MAX9996, which is pin-pin and functionally compat-
ible with the MAX9994.
RF Input and Balun
The MAX9994 RF input is internally matched to 50Ω,
requiring no external matching components. A DC-
blocking capacitor is required because the input is
internally DC shorted to ground through the on-chip
balun. Input return loss is typically 21dB over the entire
1700MHz to 2200MHz RF frequency range.
LO Inputs, Buffer, and Balun
The MAX9994 can be used for either high-side or low-
side injection applications with a 1400MHz to 2000MHz
LO frequency range. For a device with a 1900MHz to
2400MHz LO frequency range, refer to the MAX9996
data sheet. As an added feature, the MAX9994 includes
an internal LO SPDT switch that can be used for fre-
quency-hopping applications. The switch selects one of
the two single-ended LO ports, allowing the external
oscillator to settle on a particular frequency before it is
Pin Description
PIN NAME FUNCTION
1, 6, 8, 14 VCC Power-Supply Connection. Bypass each VCC pin to GND with capacitors as shown in the Typical
Application Circuit.
2RF
Single-Ended 50Ω RF Input. This port is internally matched and DC shorted to GND through a balun.
Requires an external DC-blocking capacitor.
3 TAP Center Tap of the Internal RF Balun. Bypass to GND with capacitors close to the IC, as shown in the
Typical Application Circuit.
4, 5, 10, 12,
13, 17 GND Ground
7 LOBIAS Bias Resistor for Internal LO Buffer. Connect a 549Ω ±1% resistor from LOBIAS to the power supply.
9 LOSEL Local Oscillator Select. Logic control input for selecting LO1 or LO2.
11 LO1 Local Oscillator Input 1. Drive LOSEL low to select LO1.
15 LO2 Local Oscillator Input 2. Drive LOSEL high to select LO2.
16 LEXT External Inductor Connection. Connect a low-ESR, 10nH inductor from LEXT to GND. This inductor
carries approximately 100mA DC current.
18, 19 IF-, IF+ Differential IF Outputs. Each output requires external bias to VCC through an RF choke (see the Typical
Application Circuit).
20 IFBIAS IF Bias Resistor Connection for IF Amplifier. Connect an 806Ω resistor from IFBIAS to GND.
— EP Exposed Pad. Solder the exposed pad to the ground plane using multiple vias.
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
12 ______________________________________________________________________________________
switched in. LO switching time is typically less than
50ns, which is more than adequate for virtually all GSM
applications. If frequency hopping is not employed, set
the switch to either of the LO inputs. The switch is con-
trolled by a digital input (LOSEL): logic-high selects
LO2, logic-low selects LO1. LO1 and LO2 inputs are
internally matched to 50Ω, requiring only a 22pF DC
blocking capacitor.
A two-stage internal LO buffer allows a wide input
power range for the LO drive. All guaranteed specifica-
tions are for an LO signal power from -3dBm to +3dBm.
The on-chip low-loss balun, along with an LO buffer,
drives the double-balanced mixer. All interfacing and
matching components from the LO inputs to the IF out-
puts are integrated on-chip.
High-Linearity Mixer
The core of the MAX9994 is a double-balanced, high-
performance passive mixer. Exceptional linearity is pro-
vided by the large LO swing from the on-chip LO
buffer. When combined with the integrated IF ampli-
fiers, the cascaded IIP3, 2RF - 2LO rejection, and NF
performance is typically 26.2dBm, 67dBc, and 9.7dB,
respectively.
Differential IF Output Amplifier
The MAX9994 mixer has a 40MHz to 350MHz IF fre-
quency range. The differential, open-collector IF output
ports require external pullup inductors to VCC. Note that
these differential outputs are ideal for providing
enhanced 2RF - 2LO rejection performance. Single-
ended IF applications require a 4:1 balun to transform
the 200Ωdifferential output impedance to a 50Ωsingle-
ended output. After the balun, the IF return loss is bet-
ter than 15dB.
Applications Information
Input and Output Matching
The RF and LO inputs are internally matched to 50Ω.
No matching components are required. Return loss at
the RF port is typically 21dB over the 1700MHz to
2200MHz input range, and the return loss at the LO
port is typically better than 14dB (1400MHz to
2000MHz). RF and LO inputs require only DC-blocking
capacitors for interfacing.
The IF output impedance is 200Ω(differential). For
evaluation, an external low-loss 4:1 (impedance ratio)
balun transforms this impedance down to a 50Ωsingle-
ended output (see the
Typical Application Circuit
).
Bias Resistors
Bias currents for the LO buffer and the IF amplifier are
optimized by fine tuning resistors R1 and R2. If
reduced current is required at the expense of perfor-
mance, contact the factory for details. If the ±1% bias
resistor values are not readily available, substitute stan-
dard ±5% values.
LEXT Inductor
Short LEXT to ground using a 0Ωresistor. For applica-
tions requiring improved RF-to-IF and LO-to-IF isolation,
a 10nH inductor (L3) can be used in place of the 0Ω
resistor. However, in order to ensure stable operation,
the mixer IF ports must be presented with a low com-
mon-mode load impedance. Contact the factory for
details. Since approximately 100mA flows through
LEXT, it is important to use a low-DCR wire-wound
inductor.
Layout Considerations
A properly designed PC board is an essential part of
any RF/microwave circuit. Keep RF signal lines as short
as possible to reduce losses, radiation, and induc-
tance. For the best performance, route the ground pin
traces directly to the exposed pad under the package.
The PC board exposed pad MUST be connected to the
ground plane of the PC board. It is suggested that mul-
tiple vias be used to connect this pad to the lower level
ground planes. This method provides a good RF/ther-
mal conduction path for the device. Solder the exposed
pad on the bottom of the device package to the PC
board. The MAX9994 evaluation kit can be used as a
reference for board layout. Gerber files are available
upon request at www.maxim-ic.com.
Power-Supply Bypassing
Proper voltage-supply bypassing is essential for high-
frequency circuit stability. Bypass each VCC pin and
TAP with the capacitors shown in the
Typical
Application Circuit
; see Table 1. Place the TAP bypass
capacitor to ground within 100 mils of the TAP pin.
Exposed Pad RF/Thermal Considerations
The exposed pad (EP) of the MAX9994’s 20-pin thin
QFN-EP package provides a low thermal-resistance
path to the die. It is important that the PCB on which the
MAX9994 is mounted be designed to conduct heat
from the EP. In addition, provide the EP with a low-
inductance path to electrical ground. The EP MUST be
soldered to a ground plane on the PCB, either directly
or through an array of plated via holes.
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
______________________________________________________________________________________ 13
COMPONENT VALUE DESCRIPTION
C1 4pF Microwave capacitor (0603)
C2, C6, C7, C8, C10, C12 22pF Microwave capacitors (0603)
C3, C5, C9, C11 0.01µF Microwave capacitors (0603)
C4 10pF Microwave capacitor (0603)
C13, C14 150pF Microwave capacitors (0603)
C15 150pF Microwave capacitor (0402)
L1, L2 470nH Wire-wound high-Q inductors (0805)
L3 10nH Wire-wound high-Q inductor (0603)
R1 806±1% resistor (0603)
R2 549±1% resistor (0603)
R3 7.15±1% resistor (1206)
T1 4:1 balun IF balun
U1 MAX9994 Maxim IC
Table 1. Component List Referring to the Typical Application Circuit
Pin Configuration/Functional Diagram
MAX9994
1
2
3
4
5
15
14
13
12
11
6
7
8
9
10
20
19
18
17
16
GND
LOSEL
LOBIAS
TAP
RF
VCC
VCC
VCC
VCC
GND
GND
LO2
GND
LEXT
IFBIAS
IF-
IF+
GND
LO1
GND
+
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
14 ______________________________________________________________________________________
Typical Application Circuit
MAX9994
1
2
3
4
5
15
14
13
12
11
6
7
8
9
10
20
19
18
17
16
GND
C4
C11
C6 C7
R2
C3
C14
C13
C15
C5
C1
RF
INPUT
C10
C12
LO1
INPUT
LO2
INPUT
IF
OUTPUT
LOSEL
LOBIAS
C2
C8
C9
TAP
RF
VCC
VCC
VCC
LOSEL
INPUT
VCC
VCC
VCC
VCC
R1
R3
L2
L1
L3
1
3
2
6
4
T1
VCC
VCC
GND
GND
LO2
GND
LEXT
IFBIAS
IF-
IF+
GND
LO1
GND
Chip Information
PROCESS: SiGe BiCMOS
Package Information
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
20 TQFN-EP T2055+3 21-0140 90-0008
MAX9994
SiGe High-Linearity, 1400MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
15
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 10/04 Initial release —
1 12/10
Updated Title, General Description, Ordering Information, Absolute Maximum Ratings,
Electrical Characteristics, Typical Operating Characteristics, Pin Description, General
Description, and Applications Information sections
1–12
