19-1135; Rev 1; 8/03
IT
TION K
VALUA
E
BLE
AVAILA
DC-to-Microwave,
+5V Low-Noise Amplifier
____________________________Features
o
Internally Biased
o
High Gain: 18.3dB at 900MHz
o
3.9dB Noise Figure
o
Single +4.5V to +5.5V Operation
o
-1dBm Output 1dB Compression Power
o
Low-Cost Silicon Bipolar Design
o
Ultra-Small SOT143 Package
_______________General Description
The MAX2650 is a low-noise amplifier for use from DC
to microwave frequencies. Operating from a single +5V
supply, it has a flat gain response to 900MHz. The
MAX2650’s low noise figure and high drive capability
make it ideal for a variety of transmit, receive, and
buffer applications.
The device is internally biased, eliminating the need for
external bias resistors or inductors. In a typical applica-
tion, the only external components needed are input
and output blocking capacitors and a V
CC
bypass
capacitor.
The MAX2650 comes in a 4-pin SOT143 package,
requiring minimal board space.
MAX2650
________________________Applications
Wireless Local Loop
Global Positioning Systems (GPS)
ISM Radios
Special Mobile Radios
Wireless Local-Area Networks
Cellular Base Stations
Set-Top Boxes
PART
MAX2650EUS-T
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
4 SOT143-4
______________Ordering Information
__________Typical Operating Circuit
__________________Pin Configuration
TOP VIEW
OUT
C
BLOCK
OUT
V
CC
C
BYP
V
CC
OUT
3
4
V
CC
MAX2650
GND
IN
IN
C
BLOCK
GND
2
1
IN
MAX2650
SOT143
________________________________________________________________
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.
DC-to-Microwave, +5V Low-Noise Amplifier
MAX2650
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ..............................................................-0.3V to +8V
Input Power ....................................................................+13dBm
Continuous Power Dissipation (T
A
= +70°C)
SOT143-4 (derate 4mW/°C above +70°C)...................320mW
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
ELECTRICAL CHARACTERISTICS
(V
CC
= +5.0V, Z
0
= 50Ω, f
IN
= 900MHz, T
A
= +25°C, unless otherwise noted.)
PARAMETER
Operating Temperature Range
Power Gain
Output 1dB Compression Point
Output IP3
Noise Figure
Maximum Input Voltage Standing-Wave Ratio
Maximum Output Voltage Standing-Wave Ratio
Group Delay
Supply Voltage
Supply Current
T
A
= T
MIN
to T
MAX
V
CC
= 4.5V to 5.5V
4.5
15.5
13.0
11.0
17.7
17.7
17.7
f
IN
= 100MHz to 1000MHz
f
IN
= 800MHz to 1000MHz
(Note 1)
CONDITIONS
MIN
-40
16.5
18.3
-1
10
3.9
1.5:1
1.3:1
300
5.5
20.0
22.0
24.0
mA
ps
V
TYP
MAX
85
21
UNITS
°C
dB
dBm
dBm
dB
Note 1:
Parts are designed to operate over specified temperature range. Specifications are production tested and guaranteed
at +25°C.
2
_______________________________________________________________________________________
DC-to-Microwave, +5V Low-Noise Amplifier
__________________________________________Typical Operating Characteristics
(V
CC
= 5.0V, Z
0
= 50Ω, f
IN
= 900MHz, T
A
= +25°C, unless otherwise noted.)
MAX2650
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX2650-01
OUTPUT 1dB COMPRESSION
POINT vs. FREQUENCY
MAX2650-02
OUTPUT 1dB COMPRESSION
POINT vs. FREQUENCY
MAX2650-03
40
5
+5
3
30
I
CC
(mA)
+85°C
P
-1
(dBm)
1
+85°C
-1
-40°C
+25°C
0
4.0
4.5
5.0
V
CC
(V)
5.5
6.0
-5
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
FREQUENCY (GHz)
P
-1
(dBm)
+3
5.5V
+1
5.0V
4.5V
20
-40°C
10
+25°C
-1
-3
-3
-5
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
FREQUENCY (GHz)
GAIN vs. FREQUENCY
MAX2650-04
GAIN vs. FREQUENCY
5.5V
20
GAIN (dB)
MAX2650-05
25
+85°C
25
20
GAIN (dB)
15
+25°C
-40°C
15
4.5V
10
5.0V
10
5
5
0
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
FREQUENCY (GHz)
0
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
FREQUENCY (GHz)
NOISE FIGURE vs. FREQUENCY
MAX2650-07
VOLTAGE STANDING-WAVE RATIO
vs. FREQUENCY
MAX2650-06
5
3.5:1
4
NOISE FIGURE (dB)
+85°C
+25°C
-40°C
VSWR
3.0:1
3
2.5:1
2
2.0:1
OUT
1
1.5:1
IN
0
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
FREQUENCY (GHz)
1.0:1
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
FREQUENCY (GHz)
_______________________________________________________________________________________
3
DC-to-Microwave, +5V Low-Noise Amplifier
MAX2650
______________________________________________________________Pin Description
PIN
NAME
IN
FUNCTION
Amplifier Input. Use a series blocking capacitor with less than 3Ω reactance at your lowest operating
frequency.
Ground Connection. For optimum performance, provide a low-inductance connection to the ground
plane.
Amplifier Output. Use a series blocking capacitor with less than 3Ω reactance at your lowest operat-
ing frequency.
Supply Connection. Bypass directly at the package pin. The value of the bypass capacitor is deter-
mined by the lowest operating frequency and is typically the same as the blocking capacitor value.
For long V
CC
lines, additional bypassing may be necessary.
1
2
GND
3
OUT
4
V
CC
Table 1. Typical Scattering Parameters
(V
CC
= +5V, Z
0
= 50Ω, T
A
= +25°C.)
FREQUENCY
(GHz)
S11
(mag)
S11
(ang)
S21
(dB)
S21
(mag)
S21
(ang)
S12
(dB)
S12
(mag)
S12
(ang)
S22
(mag)
S22
(ang)
K
0.05
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
1.20
1.40
1.60
1.80
2.00
2.20
2.40
2.50
4
0.17
0.17
0.16
0.14
0.16
0.16
0.17
0.18
0.18
0.20
0.20
0.19
0.16
0.15
0.22
0.33
0.41
0.44
0.44
-3
-6
9
8
0
-7
-17
-26
-39
-54
-66
-86
-86
-66
-40
-36
-38
-37
-37
19.8
19.8
19.7
19.7
19.6
19.5
19.3
19.0
18.6
18.0
17.4
15.7
13.4
10.6
7.4
4.6
3.1
2.5
2.3
9.76
9.72
9.69
9.70
9.52
9.43
9.21
8.93
8.46
7.92
7.40
6.10
4.69
3.40
2.35
1.70
1.43
1.34
1.30
177
172
161
151
140
129
119
107
95
84
73
51
31
14
5
4
6
6
4
-37.8
-36.7
-35.8
-35.0
-33.8
-33.2
-32.3
-31.7
-31.1
-29.5
-28.7
-26.9
-25.5
-24.4
-24.4
-25.3
-26.5
-28.6
-29.5
0.013
0.015
0.016
0.018
0.020
0.022
0.024
0.026
0.028
0.033
0.037
0.045
0.053
0.060
0.060
0.055
0.047
0.037
0.034
8
14
23
28
32
34
37
41
44
48
50
52
51
44
32
22
21
22
22
0.42
0.39
0.37
0.35
0.32
0.28
0.25
0.21
0.17
0.13
0.10
0.05
0.12
0.24
0.35
0.43
0.46
0.49
0.49
-5
-6
-13
-19
-26
-34
-43
-53
-62
-71
-76
-49
-12
-17
-27
-33
-33
-29
-25
3.18
2.92
2.70
2.54
2.31
2.24
2.12
2.09
2.10
1.91
1.88
1.88
2.03
2.32
3.01
3.97
4.85
6.26
7.05
_______________________________________________________________________________________
DC-to-Microwave, +5V Low-Noise Amplifier
_______________Detailed Description
The MAX2650 is a broadband amplifier with flat gain
and 50Ω input and output ports. Its small size and inter-
nal bias circuitry make it ideal for applications where
board space is limited.
PC Board Layout Example
An example PC board layout is given in Figure 1. It
uses FR-4 with 31mil layer thickness between the RF
lines and the ground plane. The board satisfies all the
above requirements.
MAX2650
__________Applications Information
External Components
As shown in the
Typical Operating Circuit,
the
MAX2650 is easy to use. Input and output series
capacitors may be necessary to block DC bias volt-
ages (generated by the MAX2650) from interacting with
adjacent circuitry. These capacitors must be large
enough to contribute negligible reactance in a 50Ω sys-
tem at the minimum operating frequency. Use the fol-
lowing equation to calculate their minimum value:
C
BLOCK
=
53,000
f
MAX2650
RF IN
RF OUT
(pF)
where f (in MHz) is the minimum operating frequency.
The V
CC
pin must be RF bypassed for correct opera-
tion. To accomplish this, connect a capacitor between
the V
CC
pin and ground, as close to the package as is
practical. Use the same equation given above (for DC
blocking capacitor values) to calculate the minimum
capacitor value. If there are long V
CC
lines on the PC
board, additional bypassing may be necessary. This
may be done further away from the package, at your
discretion.
Proper grounding of the GND pin is essential. If the PC
board uses a topside RF ground, the GND pin should
connect directly to it. For a board where the ground
plane is not on the component side, the best technique
is to connect the GND pin to it through multiple plated
through-holes.
V
CC
EXPANDED VIEW
Figure 1. Example PC Board Layout
_______________________________________________________________________________________
5
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