19-0492; Rev 0; 10/05
IT
TION K
VALUA
E
BLE
AVAILA
450MHz CDMA/OFDM LNA/Mixer
General Description
The MAX2335 RF front-end receiver IC is designed for
CDMA and OFDM applications in the 450MHz band.
The MAX2335 includes a low-noise amplifier (LNA) with
adjustable IIP3 to minimize desensitization due to cross-
modulation in the presence of a large interfering signal.
The mixer features differential IF outputs and is
designed for high linearity and low noise, which is well
suited for CDMA and OFDM applications.
An on-chip frequency divider is included to allow the
use of a standard 1GHz VCO. Alternatively, the divider
can be bypassed for use with a lower-frequency VCO.
The MAX2335 is available in a 28-pin TQFN package
with exposed paddle and is specified for the -40°C to
+85°C extended temperature range. The device is also
offered in a lead-free package.
♦
1.5dB LNA Noise Figure
♦
16dB LNA Gain
♦
2.1dB Cascaded Noise Figure
♦
Adjustable LNA IIP3
♦
LO Output Buffer for Transmitter
♦
LO Frequency Divider
♦
Small 5mm x 5mm, 28-Pin (Lead-Free) TQFN
Package
Features
MAX2335
Ordering Information
PART
MAX2335ETI
MAX2335ETI+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
28 Thin QFN-EP*
(5mm x 5mm)
28 Thin QFN-EP*
(5mm x 5mm)
PKG
CODE
T2855-3
T2855+3
*EP
= Exposed paddle.
+Denotes
lead-free package.
Applications
IF_CDMA+
IF_CDMA-
R
BIAS
Pin Configuration/
Functional Diagram
TOP VIEW
BUFFEN
N.C.
V
CC
16
V
CC
15
14
N.C.
LO_OUT
I.C.
N.C.
LO_IN
LO/2
N.C.
13
12
11
÷2
EP
N.C. 27
LNAOUT 28
+
1
DEGEN
2
R
LNA
3
GND
4
LNAIN
5
MODEO
6
MODE1
7
MODE2
9
8
10
450MHz-Band, WCDMA, IS-95, IS-2000, OFDM,
Wireless Data Links
21
MIXIN 22
I.C. 23
N.C. 24
N.C. 25
V
CC
26
20
19
18
17
MAX2335
THIN QFN
5mm x 5mm
________________________________________________________________
Maxim Integrated Products
1
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.
450MHz CDMA/OFDM LNA/Mixer
MAX2335
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ...........................................................-0.3V to +4.3V
All Other Pins to GND.................................-0.3V to (V
CC
+ 0.3V)
AC Input Pins (LNAIN, LO_IN, MIXIN) to GND ...............1V Peak
Continuous Power Dissipation (T
A
= +70°C)
28-Pin Thin QFN (derate 34.5mW/°C above +70°C) ...........2.7W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
CAUTION!
ESD SENSITIVE DEVICE
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.9V to +3.3V, R
BIAS
= 18kΩ, R
LNA
= 24kΩ, BUFFEN = LOW, LO/2 = HIGH, T
A
= -40°C to +85°C, unless otherwise noted.
Typical values are at V
CC
= +2.9V, LOW = 0V, HIGH = +3.0V, T
A
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
Operating Supply Current
Shutdown Supply Current
LO Buffer Supply Current
Digital Input-Logic High
Digital Input-Logic Low
Digital Input Current (Logic-High)
Digital Input Current (Logic-Low)
SYMBOL
I
CC
I
CC
I
CC
V
IH
V
IL
I
IH
I
IL
-25
CONDITIONS
HGHL mode (MODE[2:0] = 111)
HGLL mode (MODE[2:0] = 101)
LG mode (MODE[2:0] = 011)
Shutdown mode (MODE[2:0] = 000)
Addition for BUFFEN = HIGH
2
0.6
5
MIN
TYP
32
24
27
0.2
7
MAX
38
29
31
10
13
µA
mA
V
V
µA
µA
mA
UNITS
AC ELECTRICAL CHARACTERISTICS
(MAX2335 EV Kit, V
CC
= +2.9V to +3.3V, f
LNAIN
= f
MIXIN
= 465MHz, f
IF
= 110MHz, f
LO
= 2 x (f
MIXIN
+ f
IF
), 50Ω system impedance,
R
BIAS
= 18kΩ, R
LNA
= 24kΩ, cascaded performance includes 2dB interstage filter loss, T
A
= -40°C to +85°C, unless otherwise
noted. Typical values are at V
CC
= +2.9V, P
LO_IN
= -7dBm, LOW = 0V, HIGH = +3.0V, T
A
= +25°C, unless otherwise noted.)
PARAMETER
OVERALL PERFORMANCE
RF Frequency Range
LO Frequency Range
IF Frequency Range
LO Input Power
LO Buffer Output Power
Return Loss
CASCADED PERFORMANCE
HIGH-GAIN, HIGH-LINEARITY MODE (MODE[2:0] = 111)
Gain
Noise Figure
Input Third-Order Intercept Point
G
NF
IIP3
(Note 1)
Including off-chip matching, T
A
= +25°C (Note 2)
T
A
= +25°C (Notes 1, 3)
-14
23.0
27
2.2
-11.5
31.5
2.6
dB
dB
dBm
f
RF
f
LO
f
IF
(Note 2)
BUFFEN = HIGH
All modes, all active ports, including
2-element matching network, if necessary
-7
-10
After optional LO/2
420 to 470
500 to 660
80 to 190
-3
-6
10
0
MHz
MHz
MHz
dBm
dBm
dB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
450MHz CDMA/OFDM LNA/Mixer
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2335 EV Kit, V
CC
= +2.9V to +3.3V, f
LNAIN
= f
MIXIN
= 465MHz, f
IF
= 110MHz, f
LO
= 2 x (f
MIXIN
+ f
IF
), 50Ω system impedance,
R
BIAS
= 18kΩ, R
LNA
= 24kΩ, cascaded performance includes 2dB interstage filter loss, T
A
= -40°C to +85°C, unless otherwise
noted. Typical values are at V
CC
= +2.9V, P
LO_IN
= -7dBm, LOW = 0V, HIGH = +3.0V, T
A
= +25°C, unless otherwise noted.)
PARAMETER
Gain
Noise Figure
Input Third-Order Intercept Point
LOW-GAIN MODE (MODE[2:0] = 011)
Gain
Noise Figure
Input Third-Order Intercept Point
LNA PERFORMANCE
HIGH-GAIN, HIGH-LINEARITY MODE (MODE[2:0] = 111)
Gain
Noise Figure
Input Third-Order Intercept Point
Gain
Noise Figure
Input Third-Order Intercept Point
Gain
Noise Figure
Input Third-Order Intercept Point
MIXER PERFORMANCE
HIGH-GAIN, HIGH-LINEARITY MODE (MODE[2:0] = 111)
Gain
Noise Figure
Input Third-Order Intercept Point
Gain
Noise Figure
Input Third-Order Intercept Point
Gain
Noise Figure
Input Third-Order Intercept Point
G
MIXER
NF
MIXER
Including off-chip matching
IIP3
MIXER
(Note 3)
G
MIXER
NF
MIXER
Including off-chip matching
IIP3
MIXER
(Note 3)
G
MIXER
NF
MIXER
Including off-chip matching
IIP3
MIXER
(Note 3)
14
7
+2
13.5
6.7
0
14
7
+2
dB
dB
dBm
dB
dB
dBm
dB
dB
dBm
G
LNA
NF
LNA
IIP3
LNA
G
LNA
NF
LNA
IIP3
LNA
G
LNA
NF
LNA
IIP3
LNA
Including off-chip matching
(Note 3)
Including off-chip matching
(Note 3)
Including off-chip matching
(Note 3)
15.5
1.7
+7
14.5
1.5
+5
-2.7
5.5
+14
dB
dB
dBm
dB
dB
dBm
dB
dB
dBm
G
NF
IIP3
(Note 1)
Including off-chip matching, T
A
= +25°C (Note 2)
T
A
= +25°C (Notes 1, 3)
3
5
9
12
7
14
15
dB
dB
dBm
SYMBOL
G
NF
IIP3
(Note 1)
Including off-chip matching, T
A
= +25°C (Note 2)
T
A
= +25°C (Notes 1, 3)
-15
CONDITIONS
MIN
21.0
TYP
26.5
2.1
-12.5
MAX
30.5
2.5
UNITS
dB
dB
dBm
MAX2335
HIGH-GAIN, LOW-LINEARITY MODE (MODE[2:0] = 101)
HIGH-GAIN, LOW-LINEARITY MODE (MODE[2:0] = 101)
LOW-GAIN MODE (MODE[2:0] = 011)
HIGH-GAIN, LOW-LINEARITY MODE (MODE[2:0] = 101)
LOW-GAIN MODE (MODE[2:0] = 011)
Note 1:
Specifications at T
A
= +25°C and +85°C are guaranteed by production test. Specifications at T
A
= -40°C are guaranteed
by design and characterization.
Note 2:
Guaranteed by design and characterization.
Note 3:
Two-tone IIP3 tested at f
RF1
= 465.9MHz and f
RF2
= 466.7MHz at -25dBm/tone.
_______________________________________________________________________________________
3
450MHz CDMA/OFDM LNA/Mixer
MAX2335
Typical Operating Characteristics
(MAX2335 EV Kit, V
CC
= +2.9V, f
LNAIN
= 465MHz, f
IF
= 110MHz, f
LO_IN
= 1150MHz, P
LO_IN
= -7dBm, R
BIAS
= 18kΩ, R
LNA
= 24kΩ,
T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT (HGHL)
vs. TEMPERATURE
MAX2335 toc01
LNA GAIN VS RF FREQUENCY
MAX2335 toc02
LNA NOISE FIGURE vs. RF FREQUENCY
MAX2335 toc03
34
20
16
12
LNA GAIN (dB)
8
4
0
LG
-4
HG
6
SUPPLY CURRENT (mA)
LNA NOISE FIGURE (dB)
32
4
LG
30
2
28
HG
26
-40
-15
10
35
60
85
TEMPERATURE (°C)
-8
400
420
440
460
480
500
RF FREQUENCY (MHz)
0
400
420
440
460
480
500
RF FREQUENCY (MHz)
LNA HGHL IIP3 vs. TEMPERATURE
MAX2335 toc04
MIXER HGHL IIP3 vs. TEMPERATURE
MAX2335 toc05
10
4
3
MIXER HGHL IIP3 (dBm)
2
1
0
-1
-2
R
BIAS
= 18kΩ
9
LNA HGHL IIP3 (dBm)
R
LNA
= 18kΩ
8
R
LNA
= 24kΩ
7
R
BIAS
= 24kΩ
6
5
-40
-15
10
35
60
85
TEMPERATURE (°C)
-40
-15
10
35
60
85
TEMPERATURE (°C)
MIXER HG NOISE FIGURE
vs. RF FREQUENCY
MAX2335 toc06
MIXER IF PORT DIFFERENTIAL
PORT IMPEDANCE
MAX2335 toc07
7.0
20
EQUIVALENT PARALLEL RESISTANCE (kΩ)
2.0
EQUIVALENT PARALLEL CAPACITANCE (pF)
MIXER HG NOISE FIGURE (dB)
15
CAPACITANCE
10
1.5
6.8
1.0
6.6
5
RESISTANCE
0.5
6.4
400
420
440
460
480
500
RF FREQUENCY (MHz)
0
0
100
200
300
400
500
RF FREQUENCY (MHz)
0
4
_______________________________________________________________________________________
450MHz CDMA/OFDM LNA/Mixer
Pin Description
PIN
1
2
3
4
5
6
7
8, 11, 14, 18,
24, 25, 27
9
10
12, 23
13
NAME
DEGEN
R
LNA
GND
LNAIN
MODE0
MODE1
MODE2
N.C.
LO/2
LO_IN
I.C.
LO_OUT
DESCRIPTION
LNA Degeneration. Connect a 1nH to 3nH inductor from DEGEN to ground.
LNA Bias. Connect an 18kΩ to 24kΩ resistor from R
LNA
to ground. Adjust R
LNA
to adjust the linearity
of the input LNA in the HGHL mode.
Ground. Connect to PC board ground plane using low-inductance vias.
RF Input. Requires a DC-blocking capacitor, which can be used as part of the matching network.
Logic Input. See Table 1.
Logic Input. See Table 1.
Logic Input. See Table 1.
No Connection. These pins are internally unconnected. Connect to the PC board ground plane.
Logic Input. Drive low to disable the LO/2. Drive high to enable the LO/2.
LO Input. Internally matched to 50Ω. Requires an external DC-blocking capacitor. The LO input
frequency can be internally divided by two prior to application to the mixer by driving LO/2 high.
Internally Connected. Leave these pins unconnected for proper operation.
LO Buffer Output. Internally matched to 50Ω. Does not require a DC-blocking capacitor. The output
frequency of the buffer is equal to the LO frequency divided by two when LO/2 is high, or the LO
frequency when LO/2 is low.
Power Supply. Bypass pins 16 and 26 to the PC board ground with a capacitor placed as close to the
pin as possible. Do not share capacitor ground vias with other ground connections.
LO Output Buffer Enable. Drive high to enable the LO output buffer. Drive low to disable the LO
output buffer.
Differential IF Output Port. Requires pullup inductors to V
CC
, which can be used as part of the
matching network.
Bias Resistor Connection. Connect an 18kΩ to 24kΩ resistor from R
BIAS
to ground. Adjust R
BIAS
to
adjust the linearity of the input LNA in all modes except HGHL and the mixer in all modes.
Mixer Input. Requires an external matching network
LNA Output. Requires an external pullup inductor to V
CC
and a DC-blocking capacitor, both of which
can be used as part of the matching network.
Exposed-Paddle Ground Connection. Solder the exposed paddle (EP) evenly to the board’s ground
plane for proper operation.
MAX2335
15, 16, 26
17
19, 20
21
22
28
—
V
CC
BUFFEN
IF_CDMA-,
IF_CDMA+
R
BIAS
MIXIN
LNAOUT
EP
_______________________________________________________________________________________
5
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