MAXIM MAX2641

19-1384; Rev 2; 8/03
KIT
ATION
EVALU
E
L
B
A
AVAIL
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
These devices are internally biased, eliminating the
need for external bias resistors and chokes. In a typical
application, the only external components needed are a
two-element input match, input and output blocking
capacitors, and a VCC bypass capacitor.
The MAX2640/MAX2641 are designed on a high-frequency, low-noise, advanced silicon-germanium
process and are offered in the space-saving 6-pin
SOT23 package.
Features
♦ Wide Operating Frequency Range
MAX2640: 400MHz to 1500MHz
MAX2641: 1400MHz to 2500MHz
♦ Low Noise Figure
MAX2640: 0.9dB at 900MHz
MAX2641: 1.2dB at 1575MHz
1.3dB at 1900MHz
1.5dB at 2450MHz
♦ High Gain
MAX2640: 15.1dB at 900MHz
MAX2641: 15.7dB at 1575MHz
14.4dB at 1900MHz
13.5dB at 2450MHz
♦ High Reverse Isolation
MAX2640: 40dB at 900MHz
MAX2641: 31dB at 1575MHz
30dB at 1900MHz
24dB at 2450MHz
♦ +2.7V to +5.5V Single-Supply Operation
♦ Low 3.5mA Supply Current
♦ Ultra-Small SOT23-6 Package
Applications
Ordering Information
400MHz/900MHz/2.4GHz ISM Radios
Cellular/PCS Handsets
GPS Receivers
Cordless Phones
Wireless LANs
PART
TEMP
RANGE
PINPACKAGE
SOT
TOP MARK
MAX2640EUT-T
-40°C to +85°C
6 SOT23-6
AAAV
MAX2641EUT-T
-40°C to +85°C
6 SOT23-6
AAAW
Pin Configuration appears at end of data sheet.
Wireless Data
Typical Operating Circuits
VCC
C4
VCC
C3
C2
C3
C4
C1
VALUE VALUE VALUE VALUE
(pF)
(pF)
(pF)
MAX2640 MAX2641 (pF)
FREQUENCY (MHz)
BIAS GENERATOR
RFIN
C1
C2
Z1
RFIN
ZM1
LNA
RF OUT
RF OUT
MAX2640/1
GND
ZM2
900
—
470
3
470
—
—
1575
100
100
470
—
1900
470
100
470
—
2450
470
100
470
Z1*
ZM1
VALUE VALUE
(nH)
(pF)
ZM2
VALUE
9.85
2
—
—
5.6
1
6.8nH
—
2.55
1
1pF
100
1.65
1
1pF
*The series inductor Z1 can be replaced by a transmission line of appropriate impedance
and electrical length.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX2640/MAX2641
General Description
The MAX2640/MAX2641 are low-cost, ultra-low-noise
amplifiers designed for applications in the cellular, PCS,
GPS, and 2.4GHz ISM frequency bands. Operating from
a single +2.7V to +5.5V supply, these devices consume
only 3.5mA of current while providing a low noise figure, high gain, high input IP3, and an operating frequency range that extends from 400MHz to 2500MHz.
The MAX2640 is optimized for 400MHz to 1500MHz
applications, with a typical performance of 15.1dB gain,
input IP3 of -10dBm, and a noise figure of 0.9dB at
900MHz. The MAX2641 is optimized for 1400MHz to
2500MHz applications, with a typical performance of
14.4dB gain, an input IP3 of -4dBm, and a noise figure
of 1.3dB at 1900MHz.
MAX2640/MAX2641
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
ABSOLUTE MAXIMUM RATINGS
VCC to GND .............................................................-0.3V to +6V
RFIN Power (50Ω source) (Note 1) ..................................+5dBm
Continuous Power Dissipation (TA = +70°C)
SOT23-6 (derate 8.7mW/°C above +70°C)..................696mW
Operating Temperature Range ...........................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-65°C to +160°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.
Note 1: Pin must be AC-coupled with a DC blocking capacitor.
CAUTION! ESD SENSITIVE DEVICE
DC ELECTRICAL CHARACTERISTICS
(VCC = +2.7V to +5.5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.0V, TA = +25°C.)
PARAMETER
CONDITIONS
Operating Supply Voltage
Operating Supply Current
MIN
TYP
2.7
TA = +25°C
3.5
TA = -40°C to +85°C
MAX
UNITS
5.5
V
4.7
6.4
mA
RF ELECTRICAL CHARACTERISTICS
(VCC = +3.0V, PRFIN = -34dBm, ZO = 50Ω, TA = +25°C, unless otherwise noted.) (Notes 2 and 3)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
1500
MHz
MAX2640 (fRFIN = 900MHz)
RFIN Frequency Range
400
Gain
12.8
15.1
dB
Gain Variation Over Temperature
TA = TMIN to TMAX
0.6
1.7
dB
Noise Figure
(Note 4)
0.9
1.1
dB
Input Return Loss
-11
dB
Output Return Loss
-14
dB
Reverse Isolation
40
dB
Input 1dB Gain Compression Point
-22
dBm
-10
dBm
Input Third-Order Intercept Point
(Note 5)
MAX2641 (fRFIN = 1900MHz)
RFIN Frequency Range
1400
Gain
12.4
2500
14.4
MHz
dB
Gain Variation Over Temperature
TA = TMIN to TMAX
0.9
2.4
dB
Noise Figure
(Note 4)
1.3
1.5
dB
Input Return Loss
-12
dB
Output Return Loss
-12
dB
Reverse Isolation
30
dB
Input 1dB Gain Compression Point
-21
dBm
-4
dBm
Input Third-Order Intercept Point
2
(Note 6)
_______________________________________________________________________________________
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
(VCC = +3.0V, PRFIN = -34dBm, ZO = 50Ω, TA = +25°C, unless otherwise noted.) (Notes 2 and 3)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
MAX2641 (fRFIN = 1575MHz)
Gain
15.7
dB
1.2
dB
Input Return Loss
-8
dB
Output Return Loss
-15
dB
Reverse Isolation
-31
dB
Input 1dB Gain Compression Point
-21
dBm
+1.4
dBm
13.5
dB
1.5
dB
Input Return Loss
-10
dB
Output Return Loss
-11
dB
Reverse Isolation
-24
dB
-19
dBm
-2.5
dBm
Noise Figure
(Note 4)
Input Third-Order Intercept Point
(Note 7)
MAX2641 (fRFIN = 2450MHz)
Gain
Noise Figure
(Note 4)
Input 1dB Gain Compression Point
Input Third-Order Intercept Point
(Note 8)
Note 2: Guaranteed by design and characterization.
Note 3: Measured using typical operating circuit. Input and output impedance matching networks were optimized for best simultaneous gain and noise-figure performance.
Note 4: External component and circuit losses degrade noise-figure performance. Specification excludes external component and
circuit board losses.
Note 5: Measured with two input tones, f1 = 899MHz, f2 = 901MHz, both at -34dBm per tone.
Note 6: Measured with two input tones, f1 = 1899MHz, f2 = 1901MHz, both at -34dBm per tone.
Note 7: Measured with two input tones, f1 = 1574MHz, f2 = 1576MHz, both at -34dBm per tone.
Note 8: Measured with two input tones, f1 = 2449MHz, f2 = 2451MHz, both at -34dBm per tone.
Typical Operating Characteristics
(VCC = +3V, PRFIN = -34dBm, Typical Operating Circuits, TA = +25°C, unless otherwise noted.)
MAX2640
SUPPLY CURRENT vs. SUPPLY VOLTAGE
TA = -40°C
TA = +85°C
3
TA = -40°C
NOISE FIGURE (dB)
15
TA = +25°C
GAIN (dB)
ICC (mA)
4
TA = +25°C
14
TA = +85°C
2
MAX2640-03
5
3
MAX2640-01
16
MAX2640-01
6
MAX2640 MATCHED AT 900MHz
NOISE FIGURE vs. FREQUENCY
MAX2640 MATCHED AT 900MHz
GAIN vs. FREQUENCY
TA = +85°C
2
TA = +25°C
1
13
TA = -40°C
1
0
0
12
2
3
4
VCC (V)
5
6
800
840
880
920
FREQUENCY (MHz)
960
1000
800
840
880
920
960
1000
FREQUENCY (MHz)
_______________________________________________________________________________________
3
MAX2640/MAX2641
RF ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(VCC = +3V, PRFIN = -34dBm, Typical Operating Circuits, TA = +25°C, unless otherwise noted.)
-10
-9
REVERSE ISOLATION (dB)
-8
INPUT RETURN LOSS
-10
-11
-12
-13
-14
-15
6
5
TA = +85°C
-20
4
TA = +25°C
ICC (mA)
-7
MAX2641
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX2640-05
0
MAX2640-04
-6
MAX2640 MATCHED AT 900MHz
REVERSE ISOLATION vs. FREQUENCY
MAX2640-06
MAX2640 MATCHED AT 900MHz
INPUT RETURN LOSS AND
OUTPUT RETURN LOSS vs. FREQUENCY
RETURN LOSS (dB)
-30
3
-40
2
-50
1
TA = -40°C
OUTPUT RETURN LOSS
-16
0
-60
800
850
900
950
1000
800
840
FREQUENCY (MHz)
880
920
960
1000
2
4
NOISE FIGURE (dB)
14
TA = +25°C
MAX2640-08
3
MAX2640-07
TA = -40°C
15
TA = +85°C
5
VCC (V)
MAX2641 MATCHED AT 1900MHz
NOISE FIGURE vs. FREQUENCY
16
GAIN (dB)
3
FREQUENCY (MHz)
MAX2641 MATCHED AT 1900MHz
GAIN vs. FREQUENCY
TA = +85°C
2
TA = +25°C
1
TA = -40°C
13
0
12
1800
1840
1880
1920
1960
1800
2000
1840
1880
1920
1960
2000
FREQUENCY (MHz)
FREQUENCY (MHz)
MAX2641 MATCHED AT 1900MHz
INPUT RETURN LOSS AND
OUTPUT RETURN LOSS vs. FREQUENCY
MAX2641 MATCHED AT 1900MHz
REVERSE ISOLATION vs. FREQUENCY
-7
-9
-10
INPUT RETURN LOSS
-11
-12
-13
-10
REVERSE ISOLATION (dB)
-8
OUTPUT RETURN LOSS
-14
MAX2640-10
0
MAX2640-09
-6
RETURN LOSS (dB)
MAX2640/MAX2641
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
-20
-30
-40
-50
-15
-60
-16
1800
1850
1900
FREQUENCY (MHz)
4
1950
2000
1800
1840
1880
1920
1960
FREQUENCY (MHz)
_______________________________________________________________________________________
2000
6
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
PIN
NAME
FUNCTION
1
RFIN
Amplifier Input. AC-couple to this pin with a DC blocking capacitor. Use recommended input matching
network (see Typical Operating Circuit).
2, 3, 5
GND
Ground. For optimum performance, provide a low inductance connection to the ground plane.
4
RFOUT
6
VCC
Amplifier Output. Use the recommended series blocking or matching capacitor (see Typical Operating
Circuit).
Supply Voltage. Bypass to ground directly at the supply pin. The value of the bypass capacitor is determined by the lowest operating frequency. Additional bypassing may be necessary for long VCC lines (see
Typical Operating Circuit).
Detailed Description
The MAX2640 and MAX2641 are ultra-low-noise amplifiers that operate with RF input frequency ranges of
400MHz to 1500MHz (MAX2640) or 1400MHz to
2500MHz (MAX2641). These devices are available in
SOT23-6 packages and contain internal bias circuitry to
minimize the number of required external components.
Their small size and low external component count
make them ideal for applications where board space is
limited.
Applications Information
External Matching Components
The MAX2640/MAX2641 are easy to use, generally
requiring only five external components as shown in the
Typical Operating Circuit. To reduce external component count further, replace external inductors with
microstrip transmission lines. The high reverse isolation
allows the tuning of the input matching network without
affecting the output match, and vice versa. Select input
and output matching networks to obtain the desired
combination of gain, noise figure, and return loss performance. The Typical Operating Circuits show the recommended input and output matching networks for
the MAX2640/MAX2641 at 900MHz and 1900MHz,
respectively. These values are optimized for best
simultaneous gain, noise figure, and return loss performance. To aid in the design of matching networks for
other frequencies, Tables 1 and 2 list typical device Sparameters and Tables 3 and 4 list typical device noise
parameters.
_______________________________________________________________________________________
5
MAX2640/MAX2641
Pin Description
MAX2640/MAX2641
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
Table 1. MAX2640 Typical Scattering Parameters at VCC = +3V, TA = +25°C
FREQUENCY
(MHz)
S11
MAG
PHASE
S21
MAG
PHASE
S12
MAG
PHASE
S22
MAG
PHASE
400
0.907
-35.1
4.62
109.1
0.001
13.5
0.302
108.4
500
0.882
-43.1
4.70
90.4
0.001
64.7
0.33
93.6
600
0.858
-50.8
4.76
70.7
0.001
55.2
0.352
81.5
700
0.832
-58.1
4.80
50.6
0.002
39.4
0.365
69.4
800
0.810
-64.9
4.85
29.5
0.004
64.2
0.384
56.8
900
0.788
-71.0
4.77
9.2
0.005
36.3
0.396
44.7
1000
0.771
-76.6
4.74
-12.0
0.007
28.0
0.412
33.5
1100
0.749
-82.3
4.55
-32.4
0.010
12.3
0.436
21.9
1200
0.735
-88.0
4.48
-53.4
0.013
-10.6
0.455
10.7
1300
0.720
-93.4
4.24
-75.9
0.015
-28.2
0.469
-0.2
1400
0.702
-98.8
4.17
-94.9
0.021
-42.9
0.482
-9.9
1500
0.688
-104.9
3.81
-117.5
0.024
-59.8
0.489
-20.2
Table 2. MAX2641 Typical Scattering Parameters at VCC = +3V, TA = +25°C
FREQUENCY
(MHz)
S11
MAG
PHASE
S21
MAG
1500
0.734
-75.5
1600
0.717
-80.3
1700
0.695
1800
1900
6
PHASE
S12
MAG
PHASE
S22
MAG
PHASE
4.397
-90.5
0.013
-80.3
0.535
17.7
4.209
-109.8
0.016
-91.9
0.514
8.6
-85.3
4.193
-131.6
0.018
-116.5
0.513
-0.5
0.678
-90.6
3.876
-150.0
0.021
-128.7
0.510
-10.6
0.661
-96.6
3.801
-173.5
0.023
-150.6
0.493
-21.6
2000
0.646
-102.6
3.456
166.9
0.026
-166.6
0.470
-32.0
2100
0.632
-108.8
3.302
146.4
0.028
171.7
0.431
-43.4
2200
0.620
-114.0
2.981
123.6
0.029
150.7
0.403
-56.1
2300
0.610
-119.4
2.781
105.3
0.033
132.2
0.374
-69.4
2400
0.604
-124.6
2.430
82.9
0.032
111.2
0.338
-86.2
2500
0.603
-128.4
2.118
64.7
0.030
95.7
0.316
-98.3
_______________________________________________________________________________________
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
MAX2640/MAX2641
Table 3. MAX2640 Typical Noise Parameters at VCC = +3V, TA = +25°C
FREQUENCY (MHz)
fMIN (dB)
Γ opt
Γ opt ANGLE
RN (Ω)
400
0.66
0.56
21
12.5
500
0.69
0.54
25
11.9
600
0.72
0.51
30
11.3
700
0.75
0.48
35
10.8
800
0.78
0.46
40
10.2
900
0.82
0.43
45
9.7
1000
0.85
0.40
50
9.3
1100
0.89
0.37
56
8.8
1200
0.93
0.35
62
8.3
1300
0.97
0.32
68
7.9
1400
1.01
0.29
77
7.4
1500
1.06
0.26
84
7.0
Table 4. MAX2641 Typical Noise Parameters at VCC = +3V, TA = +25°C
FREQUENCY (MHz)
fMIN (dB)
Γ opt
Γ opt ANGLE
RN (Ω)
1500
1.02
0.43
44
12.4
1600
1.05
0.40
47
11.8
1700
1.08
0.38
50
11.3
1800
1.10
0.36
54
10.8
1900
1.14
0.32
58
10.3
2000
1.17
0.30
62
9.9
2100
1.20
0.28
66
9.4
2200
1.23
0.25
71
9.0
2300
1.27
0.22
77
8.6
2400
1.30
0.19
82
8.3
2500
1.34
0.17
91
8.0
Layout and Power-Supply Bypassing
A properly designed PC board is essential to any
RF/microwave circuit. Be sure to use controlled impedance lines on all high-frequency inputs and outputs.
The power supply should be bypassed with decoupling
capacitors located close to the device VCC pins. For
long VCC lines, it may be necessary to add additional
decoupling capacitors. These additional capacitors
can be located further away from the device package.
Proper grounding of the GND pins is essential. 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 side, the best technique is to
connect the GND pin to the board with a plated
through-hole close to the package.
_______________________________________________________________________________________
7
Pin Configuration
TOP VIEW
RFIN 1
GND 2
MAX2640
MAX2641
GND 3
6
VCC
5
GND
4
RFOUT
SOT23-6
Package Information
(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.)
6LSOT.EPS
MAX2640/MAX2641
400MHz to 2500MHz SiGe
Ultra-Low-Noise Amplifiers
PACKAGE OUTLINE, SOT-23, 6L
21-0058
F
1
1
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.