Datasheet

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.
4V
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
= 50Ω, V
CC
= +3.0V, f
RFIN
= 2450MHz, R
BIAS
= 1.2kΩ, T
A
= +25°C, 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
= 750Ω
R
BIAS
= 1.2kΩ
R
BIAS
= 3.9kΩ
IIP3 vs. R
BIAS
MAX2644 toc11
-9
-8
-6
-7
-3
-2
-4
-5
-1
IIP3 (dBm)
0.5 1.5 2.01.0
2.5
3.0 3.5 4.0
R
BIAS
(kΩ)
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 2.01.0
2.5
3.0 3.5 4.0
R
BIAS
(kΩ)
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
1.2kΩ
6
5
4
V
CC
GND
C3
2.2pF
Length = 400mils
C2
33pF
VCC
GND
RFIN
GND
RFOUTBIAS
GAIN: 17dB
IIP3: -3dBm
Figure 1. High Gain Design