19-1094; Rev 2; 4/05
KIT
ATION
EVALU
BLE
AVAILA
DC-to-Microwave, Low-Noise Amplifier
____________________________Features
♦
Single +5V Supply Operation
♦
3dB Bandwidth: DC to 1100MHz
♦
High Gain: 18dB at 500MHz
♦
Low Noise Figure: 3.5dB at 500MHz
♦
High Drive Capability: +3dBm at 16mA I
D
♦
Ultra-Small SOT143 Package
_______________General Description
The MAX2611 is a low-voltage, low-noise amplifier for
use from DC to microwave frequencies. Operating from
a single +5V supply, it has a 3dB bandwidth of
1100MHz. The MAX2611’s low noise figure and high
drive capability make it ideal for a variety of transmit,
receive, and buffer applications.
In a typical application, the only external components
needed are input and output blocking capacitors and
a V
CC
series resistor. To improve gain and output
power, an RF choke can be added in series to the bias
resistor.
The MAX2611 comes in a 4-pin SOT143 package,
requiring minimal board space.
MAX2611
________________________Applications
Satellite Receivers
TV Tuners
Wireless Local Loops
ISM Radios
Global Positioning Systems
Wireless Local-Area Networks
Land Mobile Radios
Set-Top Boxes
________________Ordering Information
PART
MAX2611EUS-T
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
4 SOT143-4
__________Typical Operating Circuit
V
CC
__________________Pin Configuration
TOP VIEW
C
BYP
(OPTIONAL)
R
BIAS
L
CHOKE
(OPTIONAL)
OUT
GND
1
4
GND
OUT
C
BLOCK
OUT
MAX2611
GND
GND
IN
2
3
IN
IN
C
BLOCK
SOT143
MAX2611
________________________________________________________________
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, Low-Noise Amplifier
MAX2611
ABSOLUTE MAXIMUM RATINGS
I
D
.........................................................................................40mA
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
(I
D
= 16mA, Z
0
= 50Ω, f
IN
= 500MHz, T
A
= +25°C, unless otherwise noted.)
PARAMETER
Operating Temperature Range
Power Gain
Gain Flatness
3dB Bandwidth
Input Voltage Standing-Wave
Maximum Ratio
Output Voltage Standing-Wave
Maximum Ratio
Output 1dB Compression Point
Noise Figure
Output IP3
Group Delay
Device Voltage
Device Voltage
Temperature Coefficient
3.5
T
A
= T
MIN
to T
MAX
(Note 2)
3.25
f
IN
= 100MHz to 1500MHz
f
IN
= 100MHz to 1500MHz
(Note 1)
f
IN
= 100MHz
f
IN
= 500MHz
f
IN
= 100MHz to 500MHz
CONDITIONS
MIN
-40
17.3
19.0
18.3
±0.3
1100
1.9:1
1.6:1
2.9
3.5
13
210
3.8
3.8
-6.1
4.0
4.26
dBm
dB
dBm
ps
V
mV/°C
TYP
MAX
85
UNITS
°C
dB
dB
MHz
Note 1:
Parts are designed to operate over specified temperature range. Specifications are production tested and guaranteed
at +25°C.
Note 2:
Guaranteed by design, not tested.
2
_______________________________________________________________________________________
DC-to-Microwave, Low-Noise Amplifier
__________________________________________Typical Operating Characteristics
(I
D
= 16mA, Z
0
= 50Ω, f
IN
= 500MHz, T
A
= +25°C, unless otherwise noted.)
MAX2611
GAIN vs. FREQUENCY
MAX2611-01
VOLTAGE STANDING-WAVE RATIO
vs. FREQUENCY
MAX2611-02
OUTPUT 1dB COMPRESSION
POINT vs. FREQUENCY
T
A
= +85°C
4
T
A
= +25°C
MAX2611-03
25
5:1
5
20
T
A
= -40°C
GAIN (dB)
VSWR
15
T
A
= +85°C
4:1
P
-1
(dBm)
3
T
A
= -40°C
3:1
10
2:1
5
IN
1:1
0.05 0.10
0.30 0.50
1.00
3.00 6.00
0.05 0.10
0.30 0.50
1.00
FREQUENCY (GHz)
FREQUENCY (GHz)
OUT
3.00 6.00
2
1
0
0
0.1
0.2
0.3 0.4 0.5
FREQUENCY (GHz)
1.0
2.0
NOISE FIGURE vs. FREQUENCY
MAX2611-04
GAIN vs. CURRENT
0.16GHz
20
0.5GHz
15
1.0GHz
MAX2611-05
7
25
6
NOISE FIGURE (dB)
5
T
A
= +85°C
4
T
A
= +25°C
T
A
= -40°C
GAIN (dB)
10
2.0GHz
3
5
2
0.1
0.2
0.3 0.4 0.5
FREQUENCY (GHz)
1.0
2.0
0
10
15
20
25
30
35
I
D
(mA)
_______________________________________________________________________________________
3
DC-to-Microwave, Low-Noise Amplifier
MAX2611
______________________________________________________________Pin Description
PIN
1
NAME
OUT
FUNCTION
Amplifier Output. Use a series blocking capacitor with less than 3Ω reactance at your lowest operat-
ing frequency. Bias with an external resistor and an optional RF choke.
Ground Connection. For optimum performance, provide a low-inductance connection to the ground
plane.
Amplifier Input. Use a series blocking capacitor with less than 3Ω reactance at your lowest operating
frequency.
2, 4
GND
3
IN
Table 1. Typical Scattering Parameters
(I
D
= 16mA, Z
0
= 50Ω, T
A
= +25°C)
FREQUENCY
(GHz)
0.1
0.2
0.3
0.4
0.5
0.6
0.8
1.0
1.5
2.0
2.5
3.0
3.5
4.0
S11
(mag)
0.12
0.11
0.13
0.14
0.15
0.15
0.13
0.12
0.32
0.31
0.32
0.20
0.24
0.31
S11
(ang)
-11
-44
-58
-78
-89
77
50
16
-60
-72
-76
-70
-64
-68
S21
(dB)
19.0
18.8
18.6
18.5
18.3
18.1
17.4
16.6
14.1
10.3
7.9
5.9
3.0
-0.7
S21
(mag)
8.90
8.73
8.53
8.43
8.26
7.99
7.45
6.79
5.07
3.27
2.48
1.98
1.41
0.92
S21
(ang)
173
166
158
151
144
137
123
109
79
59
47
32
13
17
S12
(dB)
-22.6
-21.9
-21.6
-21.6
-21.6
-21.6
-21.6
-20.9
-21.8
-22.2
-22.6
-22.3
-21.4
-23.0
S12
(mag)
0.074
0.081
0.083
0.083
0.083
0.083
0.083
0.090
0.081
0.078
0.074
0.077
0.086
0.070
S12
(ang)
2
4
5
6
7
9
10
10
11
18
25
37
30
35
S22
(mag)
0.05
0.03
0.04
0.06
0.08
0.09
0.10
0.10
0.21
0.22
0.26
0.24
0.19
0.24
S22
(ang)
53
12
45
32
34
26
23
35
-86
-72
-53
-29
47
82
K
1.08
1.06
1.05
1.06
1.06
1.07
1.10
1.11
1.29
1.87
2.44
3.10
3.83
6.66
4
_______________________________________________________________________________________
DC-to-Microwave, Low-Noise Amplifier
_______________Detailed Description
The MAX2611 is a broadband amplifier with flat gain
and 50Ω input and output ports. Its small size and sim-
ple bias circuitry make it ideal for applications where
board space is limited.
Grounding
Proper grounding of the GND pins is essential. If the
PC board uses a topside RF ground, the GND pins
should be connected directly to it. For a board where
the ground plane is not on the component side, the
best technique is to connect the GND pins to it through
multiple plated through-holes.
MAX2611
__________Applications Information
External Components
As shown in the
Typical Operating Circuit,
the
MAX2611 is easy to use. Input and output series
capacitors may be necessary to block DC bias volt-
ages (generated by the MAX2611) from interacting with
adjacent circuitry. These capacitors must be large
enough to contribute negligible reactance in a 50Ω
system at the minimum operating frequency. Use the
following equation to calculate their minimum value:
C
BLOCK
=
53,000
f
(pF)
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. This board satisfies all the
above requirements.
where f (in MHz) is the minimum operating frequency.
Bias current is supplied to the MAX2611 through an
external resistor and optional RF choke connected
between V
CC
and the OUT pin. A bypass capacitor
from V
CC
to GND may be necessary to isolate the V
CC
line from other circuitry. The resistor value determines
the bias current from the following equation:
I
D
=
V
CC
- V
D
R
BIAS
where V
D
is the device voltage, nominally 3.8V.
An optional RF choke can be added to improve the
MAX2611’s gain and output power. The choke should
be large enough to reduce the loading effect that the
bias resistor has on the amplifier output. This is a func-
tion of R
BIAS
, frequency of operation, and output
impedance.
EXPANDED VIEW
Figure 1. Example PC Board Layout
_______________________________________________________________________________________
5