EVALUATION KIT
AVAILABLE
MAX2644
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
________________________________________________________________ Maxim Integrated Products
1
19-1786; Rev 1; 11/03
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.
GND
V
CC
RFIN
1
6
RFOUT
5
GND
BIAS
MAX2644
SC70-6
TOP VIEW
2
3
4
Pin Configuration
MAX2644
GND
BIAS
R
BIAS
1.2k
RF OUTPUT
RF INPUT
V
CC
V
CC
RFOUT
RFIN
C1
33pF
L1
3.3nH
BIAS
Typical Operating Circuit
General Description
The MAX2644 low-cost, high third-order intercept point
(IP3) low-noise amplifier (LNA) is designed for applica-
tions in 2.4GHz WLAN, ISM, and Bluetooth radio sys-
tems. It features a programmable bias, allowing the
input IP3 and supply current to be optimized for specif-
ic applications. The LNA provides up to +1dBm input
IP3 while maintaining a low noise figure of 2.0dB and a
typical gain of 16dB.
The MAX2644 is designed on a low-noise, advanced
silicon-germanium (SiGe) technology. It operates with a
+2.7V to +5.5V single supply and is available in an
ultra-small 6-pin SC70 package.
________________________Applications
Bluetooth
802.11 WLAN
Home RF
Satellite CD Radio
2.4GHz ISM Band Radios
2.4GHz Cordless Phones
Wireless Local Loop (WLL)
Features
o Low Noise Figure (2.0dB at 2450MHz)
o High Gain: 16dB
o Adjustable IP3 and Bias Current
o Low-Power Standby Mode
o On-Chip Output Matching
o +2.7V to +5.5V Single-Supply Operation
o Ultra-Small 6-Pin SC70 Package
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
TOP
MARK
MAX2644EXT-T
-40
C to +85C
6 SC70
AAG
MAX2644
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, R
BIAS
= 1.2k
, no RF signal applied, R
FIN
and R
FOUT
are AC-coupled and terminated to 50
, T
A
= -40C to
+85C. Typical values are at V
CC
= +3.0V, T
A
= +25 C, unless otherwise noted.) (Note 1)
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: Devices are production tested at T
A
= +25C. Minimum and maximum values are guaranteed by design and characterization
over temperature and supply voltages.
Note 2: Min/Max limits are guaranteed by design and characterization.
Note 3: The part has been characterized at the specified frequency range. Operation outside this range is possible but not guaranteed.
Note 4: Excluding PC board losses (0.3dB at the input and 0.3dB at the output of the MAX2644 EV kit).
Note 5: Measured with two input tones (f
1
= 2445MHz, f
2
= 2455MHz) both at -30dBm per tone. Input IP3 can be improved to
+1dBm with circuit shown in Figure 2.
Note 6: Excluding PC board losses (0.3dB typical at the input of the MAX2644 EV kit).
V
CC
to GND ..............................................................-0.3V to +6V
RFIN, RFOUT to GND.........................................................0.3V
RFIN Power (50
source) ................................................+5dBm
BIAS to GND ................................................................0 to +0.3V
Operating Temperature Range ...........................-40C to +85C
Maximum Junction Temperature .....................................+150C
Continuous Power Dissipation (T
A
= +70C)
6-Pin SC70 (derate 3.1mW/C above +70C) ..............245mW
Storage Temperature.........................................-65C to +150C
Lead Temperature (soldering, 10s) .................................+300C
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
2.7
5.5
V
R
BIAS
= 3.9k
2.7
R
BIAS
= 1.2k
, T
A
= +25C
7.0
9.7
R
BIAS
= 1.2k
, T
A
= -40C to +85C
11.0
Operating Supply Current
R
BIAS
= 750
10.2
mA
Standby Supply Current
R
BIAS
is unconnected, T
A
= +25C, V
CC
= 3.3V
100
A
AC ELECTRICAL CHARACTERISTICS
(MAX2644 EV kit, V
CC
= +3.0V, f
RFIN
= 2450MHz, P
RFIN
= -30dBm, input and output are terminated to 50
, R
BIAS
= 1.2k
,
T
A
= +25C, unless otherwise noted.) (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Operating Frequency
(Note 3)
2400
2500
MHz
Gain (Note 4)
15
17
dB
Gain Variation Over Temperature
T
A
= -40
C to +85C
0.7
1.0
dB
R
BIAS
= 750
-4
R
BIAS
= 1.2k
-3
Input Third-Order Intercept Point
(Note 5)
R
BIAS
= 3.9k
-8
dBm
Input 1dB Compression Point
-13
dBm
Noise Figure
(Note 6)
2.0
2.5
dB
Input Return Loss
-15
dB
Output Return Loss
-10
dB
Reverse Isolation
-30
dB
MAX2644
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
_______________________________________________________________________________________
3
Typical Operating Characteristics
(P
RFIN
= -30dBm, Z
S
= Z
L
= 50
, V
CC
= +3.0V, f
RFIN
= 2450MHz, R
BIAS
= 1.2k
, T
A
= +25C, unless otherwise noted.)
0
4
2
8
6
12
10
14
2.5
3.5
4.0
3.0
4.5
5.0
5.5
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX2644 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
T
A
= +25
C
T
A
= -40
C
T
A
= +85
C
R
BIAS
= 1.2k
13
15
14
17
16
18
19
0.5
2.0
2.5
1.0
1.5
3.0
3.5
4.0
GAIN vs. R
BIAS
MAX2644 toc05
R
BIAS
(k
)
GAIN (dB)
T
A
= -40
C
T
A
= +85
C
T
A
= +25
C
-20
-14
-16
-18
-12
-10
-8
-6
-4
-2
0
2200
2400
2300
2500
2600
2700
INPUT AND OUTPUT RETURN LOSS
vs. FREQUENCY
MAX2644 toc06
FREQUENCY (MHz)
REVERSE ISOLATION (dB)
OUTPUT RETURN LOSS
R
BIAS
= 1.2k
INPUT RETURN LOSS
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
2350
2400
2450
2500
2550
NOISE FIGURE vs. FREQUENCY
MAX2644 toc08
FREQUENCY (MHz)
NOSIE FIGURE (dB)
R
BIAS
= 1.2k
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
-40
-15
10
35
60
85
NOISE FIGURE vs. TEMPERATURE
MAX2644 toc09
TEMPERATURE (
C)
NOSIE FIGURE (dB)
R
BIAS
= 1.2k
10
13
12
11
14
15
16
17
18
19
20
2200
2400
2300
2500
2600
2700
GAIN vs. FREQUENCY
MAX2644 toc04
FREQUENCY (MHz)
GAIN (dB)
T
A
= -40
C
T
A
= +85
C
T
A
= +25
C
R
BIAS
= 1.2k
-50
-40
-45
-30
-35
-25
-20
2200
2400
2300
2500
2600
2700
REVERSE ISOLATION vs. FREQUENCY
MAX2644 toc07
FREQUENCY (MHz)
REVERSE ISOLATION (dB)
T
A
= +25
C
T
A
= +85
C
R
BIAS
= 1.2k
T
A
= -40
C
1
5
3
9
7
11
13
0.5
2.0
2.5
1.0
1.5
3.0
3.5
4.0
SUPPLY CURRENT vs. R
BIAS
MAX2644 toc02
R
BIAS
(k
)
SUPPLY CURRENT (mA)
T
A
= +25
C
T
A
= +85
C
T
A
= -40
C
12
15
14
13
16
17
18
19
20
21
22
2.5
3.5
3.0
4.0
4.5
5.0
5.5
GAIN vs. SUPPLY VOLTAGE
MAX2644 toc03
SUPPLY VOLTAGE (V)
GAIN (dB)
T
A
= +25
C
R
BIAS
= 1.2k
T
A
= +85
C
T
A
= -40
C
MAX2644
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
4
_______________________________________________________________________________________
Pin Description
PIN
NAME
DESCRIPTION
1
BIAS
Resistor Bias Control. Connect a resistor, R
BIAS
,
from BIAS to ground. R
BIAS
sets IP3 and supply
current. The current through this pin is approximately 60mV divided by R
BIAS
(see Applications
Information).
2, 5
GND
Ground. For optimum performance, provide a low-inductance connection to the ground plane.
3
RFIN
Amplifier Input. AC-couple to this pin with a DC blocking capacitor. External matching network is
required for optimum performance.
4
V
CC
Supply Voltage. Bypass with a capacitor directly to ground at the supply pin. Refer to V
CC
Line
Bypassing section for more information.
6
RFOUT
Amplifier Output. AC-coupled internally.
Typical Operating Characteristics (continued)
(P
RFIN
= -30dBm, Z
S
= Z
L
= 50
, V
CC
= +3.0V, f
RFIN
= 2450MHz, R
BIAS
= 1.2k
, T
A
= +25C, unless otherwise noted.)
-20
-10
-15
0
-5
5
10
-30
-20
-15
-25
-10
-5
0
OUTPUT POWER vs. INPUT POWER
MAX2644 toc10
INPUT POWER (dBm)
OUTPUT POWER (dBm)
R
BIAS
= 750
R
BIAS
= 1.2k
R
BIAS
= 3.9k
IIP3 vs. R
BIAS
MAX2644 toc11
-9
-8
-6
-7
-3
-2
-4
-5
-1
IIP3 (dBm)
0.5
1.5
2.0
1.0
2.5
3.0
3.5
4.0
R
BIAS
(k
)
T
A
= +85
C
T
A
= +25
C
T
A
= -40
C
INPUT P
1dB
vs. R
BIAS
MAX2644 toc12
-19
-18
-16
-17
-13
-12
-14
-15
-11
INPUT P
1dB
(dBm)
0.5
1.5
2.0
1.0
2.5
3.0
3.5
4.0
R
BIAS
(k
)
T
A
= +85
C
T
A
= -40
C
T
A
= +25
C
U1
MAX2644
SMA
RFIN
SMA
RFOUT
C1
33pF
L1
3.3nH
3
2
1
R1
1.2k
6
5
4
V
CC
GND
C3
2.2pF
Length = 400mils
C2
33pF
VCC
GND
RFIN
GND
RFOUT
BIAS
GAIN: 17dB
IIP3: -3dBm
Figure 1. High Gain Design
MAX2644
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
_______________________________________________________________________________________
5
Applications Information
Input Matching
Input matching is required for optimum performance.
The MAX2644 requires a simple LC matching network,
as shown in the Typical Operating Circuit. To further
reduce cost and external component count, replace the
external inductor with a microstrip transmission line.
The Typical Operating Circuit shows the recommended
input matching network for the MAX2644 at 2450MHz.
These values are optimized for best simultaneous gain,
noise figure, and return loss performance.
V
CC
Line Bypassing
Bypassing the V
CC
line is necessary for optimum
gain/linearity performance. A transmission line and two
capacitors are required, as shown in the schematics in
Figures 1 and 2. The optimum dimensions and posi-
tions of the components are as follows: the output
transmission line dimension is 0.532in (length)
0.012in
(width); the distance from C2 to the IC is 0.352in; and
the distance from C3 to the IC is 0.041in. Please refer
to Figures 1 and 2 for component values.
U1
MAX2644
SMA
RFIN
SMA
RFOUT
C1
33pF
L1
3.3nH
3
2
1
6
5
4
V
CC
GND
C3
15pF
Length = 400mils
C2
33pF
V
CC
GND
RFIN
GND
RFOUT
BIAS
GAIN: 16dB
IIP3: +1dBm
L2
3.9nH
R1
1.2k
Figure 2. High Linearity Design
MAX2644
MAX2644
BIAS
BIAS
(a)
(b)
Figure 3. Recommended MAX2644 Standby Configurations
MAX2644
Standby
Standby mode is achieved by disconnecting BIAS as
shown in Figure 1. Avoid capacitance at the BIAS pin
by connecting the bias resistor from BIAS to the switch.
Layout Issues
A properly designed PC board is essential to any
RF/microwave circuit. Use controlled impedance lines
on all high-frequency inputs and outputs. Bypass with
decoupling capacitors located close to the device V
CC
pin. For long V
CC
lines, it may be necessary to add
additional decoupling capacitors. These additional
capacitors can be located farther away from the device
package. Proper grounding of the GND pins is essen-
tial. If the PC board uses a topside RF ground, connect
it directly to all GND pins. For a board where the
ground plane is not on the component layer, the best
technique is to connect the GND pins to the board with
a plated through-hole located close to the package.
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
6
_______________________________________________________________________________________
Table 1. MAX2644 Typical Scattering Parameters
(R
BIAS
= 750
, V
CC
= +3.0V, T
A
= +25C.)
FREQ.
(MHz)
S11
MAG
S11 PHASE
(DEGREES)
S21
MAG
S21 PHASE
(DEGREES)
S12
MAG
S12 PHASE
(DEGREES)
S22
MAG
S22 PHASE
(DEGREES)
2200
0.3372
-79.36
5.1940
170.97
0.0414
157.19
0.2818
-73.71
2250
0.3098
-70.09
5.3156
166.79
0.0445
146.70
0.2204
-67.13
2300
0.3283
-57.20
5.4281
159.22
0.0469
130.62
0.1566
-50.26
2350
0.4005
-50.46
5.4175
150.70
0.0441
108.72
0.1480
-3.96
2400
0.4839
-50.28
5.3346
143.93
0.0349
85.67
0.2795
15.12
2450
0.5443
-56.33
5.0687
136.45
0.0233
58.80
0.4179
11.12
2500
0.5758
-60.09
4.9556
132.16
0.0113
27.74
0.5135
3.28
2550
0.5784
-63.61
4.5952
127.68
0.0041
-38.98
0.5622
-2.66
2600
0.5698
-66.56
4.2364
126.58
0.0063
-110.49
0.5986
-7.45
2650
0.5600
-68.51
4.1376
126.51
0.0103
-128.93
0.6208
-10.43
2700
0.5533
-69.86
4.0729
120.60
0.0133
-140.21
0.6425
-12.93
FREQ.
(MHz)
S11
MAG
S11 PHASE
(DEGREES)
S21
MAG
S21 PHASE
(DEGREES)
S12
MAG
S12 PHASE
(DEGREES)
S22
MAG
S22 PHASE
(DEGREES)
2200
0.3482
-67.06
5.2390
-177.33
0.0402
161.53
0.2873
-76.58
2250
0.3121
-58.60
5.3790
178.72
0.0435
151.97
0.2305
-69.42
2300
0.3051
-43.64
5.5982
173.43
0.0452
136.90
0.1735
-54.22
2350
0.3693
-30.34
5.8137
166.48
0.0427
116.57
0.1582
-16.42
2400
0.4769
-29.48
5.8063
158.29
0.0341
95.13
0.2687
6.52
2450
0.5619
-35.54
5.6624
150.06
0.0236
68.36
0.4043
5.00
2500
0.5948
-42.64
5.3015
142.37
0.0117
41.34
0.5030
-2.19
2550
0.5939
-47.58
4.7813
136.67
0.0034
-13.74
0.5602
-8.04
2600
0.5825
-50.94
4.3271
134.58
0.0056
-104.09
0.5952
-12.76
2650
0.5708
-53.14
4.1961
133.48
0.0096
-124.80
0.6215
-15.97
2700
0.5604
-54.35
4.1068
128.01
0.0125
-134.75
0.6434
-18.83
Table 2. MAX2644 Typical Scattering Parameters
(R
BIAS
= 1.2k
, V
CC
= +3.0V, T
A
= +25C.)
MAX2644
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
_______________________________________________________________________________________
7
Table 3. MAX2644 Typical Scattering Parameters
(R
BIAS
= 3.9k
, V
CC
= +3.0V, T
A
= +25C.)
FREQ.
(MHz)
S11
MAG
S11 PHASE
(DEGREES)
S21
MAG
S21 PHASE
(DEGREES)
S12
MAG
S12 PHASE
(DEGREES)
S22
MAG
S22 PHASE
(DEGREES)
2200
0.4894
-75.32
3.7368
-173.73
0.0348
156.35
0.2729
-62.97
2250
0.4566
-72.73
3.7718
-177.51
0.0363
147.30
0.2459
-53.68
2300
0.4335
-68.17
3.8855
177.43
0.0369
132.32
0.2211
-41.12
2350
0.4343
-61.46
3.9783
171.34
0.0344
116.21
0.2177
-21.15
2400
0.4695
-57.00
4.0230
165.15
0.0272
95.31
0.2823
-2.41
2450
0.5156
-57.52
4.0087
157.68
0.0179
70.07
0.3924
1.25
2500
0.5403
-61.04
3.8380
149.58
0.0079
42.40
0.4849
-2.71
2550
0.5423
-63.93
3.5140
143.30
0.0018
-46.47
0.5476
-7.30
2600
0.5361
-66.30
3.2048
140.25
0.0055
-112.91
0.5881
-11.35
2650
0.5280
-68.08
3.1204
138.55
0.0100
-132.25
0.6170
-14.57
2700
0.5217
-69.29
3.0860
132.16
0.0121
-133.97
0.6418
-17.44
Table 4. MAX2644 Typical Noise
Parameters at V
CC
= +3.0V, T
A
= +25C,
R
BIAS
= 750
FREQUENCY
(MHz)
F
MIN
(dB)
opt
opt
ANGLE
R
N
(
)
2400
1.725
0.361
66.13
24.38
2450
1.747
0.360
66.93
24.76
2500
1.769
0.358
67.72
25.14
Table 5. MAX2644 Typical Noise
Parameters at V
CC
= +3.0V, T
A
= +25C,
R
BIAS
= 1.2k
FREQUENCY
(MHz)
F
MIN
(dB)
opt
opt
ANGLE
R
N
(
)
2400
1.570
0.409
69.84
21.77
2450
1.589
0.408
70.63
21.94
2500
1.609
0.406
71.63
22.42
Table 6. MAX2644 Typical Noise
Parameters at V
CC
= +3.0V, T
A
= +25C,
R
BIAS
= 3.9k
FREQUENCY
(MHz)
F
MIN
(dB)
opt
opt
ANGLE
R
N
(
)
2400
1.497
0.510
86.55
20.58
2450
1.517
0.507
86.50
20.90
2500
1.538
0.504
88.18
21.25
Chip Information
TRANSISTOR COUNT: 87
MAX2644
2.4GHz SiGe,
High IP3 Low-Noise Amplifier
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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to
www.maxim-ic.com/packages
.)
SC70, 6L.EPS
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