General Description
The MAX2642/MAX2643 low-cost, high third-order inter-
cept point (IP3), low-noise amplifiers (LNAs) are
designed for applications in cellular, ISM, SMR, and
PMR systems. They feature a programmable bias,
allowing the IP3 and supply current to be optimized for
specific applications. These LNAs provide up to 0dBm
input IP3 while maintaining a low noise figure of 1.3dB.
The gain for these devices is typically 17dB. The
MAX2642 also features a 13dB attenuation step, which
extends the LNA's dynamic range. Both devices feature
a shutdown mode that minimizes power consumption.
On-chip output matching saves board space by reduc-
ing the number of external components.
The MAX2642/MAX2643 are designed on a low-noise,
advanced silicon-germanium (SiGe) process technolo-
gy. They operate from a +2.7V to +5.5V single supply
and are available in the ultra-small 6-pin SC70 package.
________________________Applications
800MHz/900MHz Cellular Phones
900MHz Cordless Phones
868MHz/900MHz ISM-Band Wireless Data
PMR/SMR/LMR
Features
o Wide Frequency Range: 800MHz to 1000MHz
o High Output IP3 and Adjustable
+17dBm at 5.3mA
+7dBm at 2.8mA
o Low Noise Figure: 1.3dB at 900MHz
o 13dB Attenuation Step (MAX2642)
o On-Chip Output Matching
o Low-Power Shutdown Mode
o +2.7V to +5.5V Single-Supply Operation
o Ultra-Small SC70-6 Package
MAX2642/MAX2643
900MHz SiGe, High IP3,
Low-Noise Amplifiers
________________________________________________________________ Maxim Integrated Products
1
GND
V
CC
RFIN
1
6
RFOUT
5
GND
BIAS
MAX2642
MAX2643
SC70-6
TOP VIEW
2
3
4
Pin Configuration
19-1682; Rev 0; 4/00
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
EVALUATION KIT MANUAL
FOLLOWS DATA SHEET
Ordering Information
6 SC70-6
PIN-
PACKAGE
TEMP. RANGE
-40°C to +85°C
MAX2642EXT-T
PART
AAC
TOP
MARK
6 SC70-6
-40°C to +85°C
MAX2643EXT-T
AAD
MAX2642
MAX2643
RF
INPUT
GND
RFIN
RFOUT
( ) ARE FOR MAX2643.
C1
3.3pF
L1
8.7nH
BIAS
V
CC
V
CC
47pF
R
BIAS
510
RF
OUTPUT
33k
(10k)
LOW GAIN
(ENABLE)
HIGH GAIN
(SHUTDOWN)
BIAS
Typical Operating Circuit
MAX2642/MAX2643
900MHz SiGe, High IP3,
Low-Noise Amplifiers
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS--MAX2642
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, no RF signal applied, RFIN and RFOUT are AC-coupled and terminated to 50
, high-
gain mode. Typical values are at V
CC
= 3.0V, T
A
= +25°C, unless otherwise noted.) (Notes 1, 2, 3)
DC ELECTRICAL CHARACTERISTICS--MAX2643
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, no RF signal applied, RFIN and RFOUT are AC-coupled and terminated to 50
. Typical
values are at V
CC
= 3.0V, T
A
= +25°C, unless otherwise noted.) (Notes 1, 8, 9)
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.
V
CC
to GND ..............................................................-0.3V to +6V
RFOUT to GND...........................................-0.3V to (V
CC
+ 0.3V)
RFIN to GND ..................................................................0 to 0.9V
RFIN Power (50
source) ................................................+5dBm
BIAS to GND ................................................................0 to +0.3V
Operating Temperature Range ...........................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Continuous Power Dissipation (T
A
= +70°C)
SC70-6 (derate 3.1mW/°C above +70°C) ...................245mW
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
2.7
5.5
V
High-gain mode, R
BIAS
= 510
, T
A
= +25
°C
5.3
6.7
R
BIAS
= 510
, T
A
= -40
°C to +85°C
7.5
R
BIAS
= 806
3.6
R
BIAS
= 1.1k
2.8
Operating Supply Current
Low-gain mode, R
BIAS
= 510
, T
A
= 25
°C
5.9
mA
Shutdown Supply Current
BIAS = unconnected (see Applications Information)
0.2
mA
High-gain mode (Note 4)
0.6
Gain Control Voltage Input
Low-gain mode (Note 5)
2.0
V
High-gain mode (Note 6)
-10
0
Gain Control Input Current
Low-gain mode (Note 7)
0
50
µA
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
2.7
5.5
V
R
BIAS
= 510
, T
A
= +25
°C
5.1
6.5
R
BIAS
= 510
, T
A
= -40
°C to +85°C
7.3
R
BIAS
= 806
3.4
Operating Supply Current
R
BIAS
= 1.1k
2.6
mA
Shutdown Supply Current
Shutdown mode (see Applications Information)
0.2
10
µA
Normal operation (Note 10)
2.0
Shutdown Control Input Voltage
Shutdown mode (Note 11)
0.6
V
Normal operation (Note 7)
0
10
Shutdown Control Input Current
Shutdown mode (Note 6)
-5
5
µA
MAX2642/MAX2643
900MHz SiGe, High IP3,
Low-Noise Amplifiers
_______________________________________________________________________________________
3
AC ELECTRICAL CHARACTERISTICS
(MAX2642/MAX2643 EV kits, P
RFIN
= -30dBm, f
RFIN
= 900MHz, input and output are terminated to 50
, V
CC
= +3.0V, T
A
= +25°C,
R
BIAS
= 510
, unless otherwise noted.) (Note 12)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Operating Frequency Range
(Note 13)
800
1000
MHz
Gain (Note 14)
T
A
= +25
°C
14.5
16.7
19
dB
Gain Variation Over Temperature
T
A
= -40
°C to +85°C
±0.35
±0.75
dB
Attenuation Step
MAX2642 only
13
dB
R
BIAS
= 510
0
R
BIAS
= 806
-5
Input Third-Order Intercept Point
(Note 15)
R
BIAS
= 1.1k
-10
dBm
-18
Input 1dB Compression Point
MAX2642, low-gain mode
-17
dBm
1.35
1.6
Noise Figure (Note 16)
MAX2642, low-gain mode
4.3
dB
-10
-12
Input Return Loss
MAX2642, low-gain mode
-10
-18
dB
-10
-14
Output Return Loss
MAX2642, low-gain mode
-10
-11
dB
-20
-26
Reverse Isolation
MAX2642, low-gain mode
-10
-17
dB
Gain-Step Response Time
MAX2642
5
10
µs
MAX2643
6
10
Shutdown Response Time
MAX2642, through series switch at BIAS
12
µs
Note 1:
Devices are production tested at T
A
= +25°C. Minimum and maximum values are guaranteed by design and characterization
over temperature and supply voltage.
Note 2:
High-gain mode is set for the MAX2642 by connecting RFOUT to GND through a 33k
resistor.
Note 3:
Low-gain mode is applicable only to the MAX2642 and is set by connecting RFOUT to V
CC
through a 33k
resistor.
Note 4:
Maximum DC voltage through a 33k
resistor that sets the MAX2642 to operate in high-gain mode.
Note 5:
Minimum DC voltage through a 33k
resistor that sets the MAX2642 to operate in low-gain mode.
Note 6:
DC current required when RFOUT is connected to GND through a 33k
resistor (MAX2642) and 10k resistor (MAX2643).
Note 7:
DC current required when RFOUT is connected to V
CC
through a 33k
resistor (MAX2642) and 10k resistor (MAX2643).
Note 8:
Normal operation is set for the MAX2643 by connecting RFOUT to V
CC
through a 10k
resistor.
Note 9:
Shutdown is set for the MAX2643 by connecting RFOUT to GND through a 10k
resistor.
Note 10: Minimum DC voltage through a 10k
resistor that sets the MAX2643 to operate in normal mode.
Note 11: Maximum DC voltage through a 10k
resistor that sets the MAX2643 to operate in shutdown mode.
Note 12: Min/Max limits are guaranteed by design and characterization, except gain is production tested at T
A
= +25°C.
Note 13: The part has been characterized at the specified frequency range. Operation outside this range is possible but not guar-
anteed.
Note 14: Devices are production tested at T
A
= +25°C.
Note 15: Measured with two input tones, f
1
= 895MHz and f
2
= 905MHz, both at -30dBm per tone.
Note 16: Excludes PC board losses (0.25dB typical at the input of the MAX2642/MAX2643 EV kit).
MAX2642/MAX2643
900MHz SiGe, High IP3,
Low-Noise Amplifiers
4
_______________________________________________________________________________________
Typical Operating Characteristics
(MAX2642/MAX2643 EV kits, V
CC
= +3.0V, P
RFIN
= -30dBm, input and output are terminated to 50
, f
RFIN
= 900MHz, R
BIAS
=
510
, high-gain mode (low-gain mode is applicable only to the MAX2642), T
A
= +25°C, unless otherwise noted.)
-15
-11
-13
-7
-9
-3
-5
-1
3
1
5
0
400 600 800
200
1000 1200 1400 1600 1800
INPUT THIRD-ORDER INTERCEPT
vs. R
BIAS
(HIGH GAIN)
MAX2642/43-01
R
BIAS
(
)
INPUT IP3 (dBm)
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
-15
-1
-3
3
1
7
5
9
11
MAX2642
INPUT THIRD-ORDER INTERCEPT
vs. R
BIAS
(LOW GAIN)
MAX2642/43-02
R
BIAS
(
)
INPUT IP3 (dBm)
0
500
1000
1500
2000
-5
-7
-9
-11
-13
T
A
= +85
°C
T
A
= +25
°C
T
A
= -40
°C
0
3
2
1
4
5
6
800
880
860
820 840
900 920 940 960 980 1000
NOISE FIGURE vs. FREQUENCY
MAX2642/43-03
FREQUENCY (MHz)
NOISE FIGURE (dB)
LOW GAIN
HIGH GAIN
MATCHED AT 900MHz
0
1
2
4
3
5
6
-40
-20
0
20
40
60
80
100
NOISE FIGURE vs. TEMPERATURE
MAX2642/43-04
TEMPERATURE (°C)
NOISE FIGURE (dB)
LOW GAIN
HIGH GAIN
-24
-20
-22
-14
-16
-18
-10
-12
-8
0
600 800
200 400
1000 1200 1400 1600 1800
P1dB vs. R
BIAS
MAX2642/43-05
R
BIAS
(
)
P1dB (dBm)
T
A
= -40
°C,
HIGH GAIN
T
A
= +85
°C, HIGH GAIN
T
A
= -40
°C, LOW GAIN
T
A
= +85
°C, LOW GAIN
T
A
= +25
°C, LOW GAIN
T
A
= +25
°C, HIGH GAIN
-28
-20
-24
-12
-16
-4
-8
0
8
4
12
-30
-22
-18
-26
-14
-10
-6
-2
2
OUTPUT POWER vs. INPUT POWER
MAX2642/43-06
P
IN
(dBm)
P
OUT
(dBm)
510
, HIGH GAIN
1.1k
, LOW GAIN
510
, LOW GAIN
806
, LOW GAIN
806
, HIGH GAIN
1.1k
, HIGH GAIN
0
4
2
8
6
12
10
14
18
16
20
0
400 600 800
200
1000 1200 1400 1600 1800
GAIN vs. R
BIAS
MAX2642/43-07
R
BIAS
(
)
GAIN (dB)
-2
-4
T
A
= +85°C, HIGH GAIN
T
A
= -40°C, HIGH GAIN
T
A
= -40°C, LOW GAIN
T
A
= +85°C, LOW GAIN
T
A
= +25°C,
HIGH GAIN
T
A
= +25°C, LOW GAIN
4
10
8
6
12
14
18
16
20
2.4
2.8
3.2
3.6
4.0
4.4
4.8
5.2
5.6
GAIN vs. SUPPLY VOLTAGE
MAX2642/43-08
V
CC
(V)
GAIN (dB)
2
0
-2
-4
T
A
= +85
°C, HIGH GAIN
T
A
= -40
°C, HIGH GAIN
T
A
= -40
°C, LOW GAIN
T
A
= +85
°C, LOW GAIN
T
A
= +25
°C, LOW GAIN
T
A
= +25
°C, HIGH GAIN
0
4
2
8
6
12
10
14
18
16
20
800
840 860 880
820
900 920 940
980
960
1000
GAIN vs. FREQUENCY
MAX2642/43-09
FREQUENCY (MHz)
GAIN (dB)
MATCHED AT 900MHz
LOW-GAIN MODE
HIGH-GAIN MODE
MAX2642/MAX2643
900MHz SiGe, High IP3,
Low-Noise Amplifiers
_______________________________________________________________________________________
5
12.6
13.0
12.8
13.4
13.2
13.8
13.6
14.0
800
880
840
920
960
820
900
860
940
980 1000
MAX2642
ATTENUATION STEP vs. FREQUENCY
MAX2642/43-10
FREQUENCY (MHz)
ATTENUATION STEP (dB)
MATCHED AT 900MHz
-35
-25
-30
-15
-20
-5
-10
0
800
880
840
920
960
820
900
860
940
980 1000
RETURN LOSS vs. FREQUENCY
(HIGH GAIN)
MAX2642/43-11
FREQUENCY (MHz)
ATTENUATION STEP (dB)
MATCHED AT 900MHz
INPUT
OUTPUT
-35
-25
-30
-15
-20
-5
-10
0
800
880
840
920
960
820
900
860
940
980 1000
MAX2642
RETURN LOSS vs. FREQUENCY
(LOW GAIN)
MAX2642/43-12
FREQUENCY (MHz)
RETURN LOSS (dB)
MATCHED AT 900MHz
INPUT
OUTPUT
-35
-25
-30
-15
-20
-5
-10
0
800
880
840
920
960
820
900
860
940
980 1000
REVERSE ISOLATION vs. FREQUENCY
MAX2642/43-13
FREQUENCY (MHz)
RETURN LOSS (dB)
MATCHED AT 900MHz
LOW GAIN
HIGH GAIN
-60
-50
-20
-10
-30
-40
0
MAX2642
HIGH/LOW-GAIN SWITCH
CHARACTERISTICS
MAX2642/43-14
TIME (400ns/div)
OUTPUT POWER (dBm)
V
RFOUT
0V
3V
-90
-70
-80
-50
-60
-40
-30
-10
-20
0
MAX2643
SHUTDOWN CHARACTERISTICS
MAX2642/43-15
TIME (4
µs/div)
OUTPUT POWER (dBm)
V
RFOUT
0V
3V
0
4
2
8
6
10
12
14
16
0
400 600
200
800 1000 1200 1400 1600
SUPPLY CURRENT vs. R
BIAS
MAX2642/43-16
R
BIAS
(
)
SUPPLY CURRENT (mA)
T
A
= +85
°C, HIGH GAIN
T
A
= -40
°C, LOW GAIN
T
A
= +85
°C, LOW GAIN
T
A
= +25
°C, LOW GAIN
T
A
= +25
°C, HIGH GAIN
T
A
= -40
°C, HIGH GAIN
0.0001
0.1
0.01
0.001
10
1
-40
-20
0
20
40
60
80
100
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX2642/43-17
TEMPERATURE (
°C)
SHUTDOWN CURRENT (
µ
A)
V
CC
= 5.5V
V
CC
= 3.0V
4.0
4.8
4.4
5.6
5.2
6.4
6.0
6.8
7.6
7.2
8.0
2.4
3.2
3.6
2.8
4.0
4.4
4.8
5.2
5.6
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX2642/43-18
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (mA)
T
A
= +85
°C, HIGH GAIN
T
A
= -40
°C, LOW GAIN
T
A
= +85
°C, LOW GAIN
T
A
= +25
°C, LOW GAIN
T
A
= +25
°C, HIGH GAIN
T
A
= -40
°C,
HIGH GAIN
Typical Operating Characteristics (continued)
(MAX2642/MAX2643 EV kits, V
CC
= +3.0V, P
RFIN
= -30dBm, input and output are terminated to 50
, f
RFIN
= 900MHz, R
BIAS
=
510
, high-gain mode (low-gain mode is applicable only to the MAX2642), T
A
= +25°C, unless otherwise noted.)
PDF 
ZIP