Rainbow Electronics MAX2644 - Manual (Page 4)

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.
4 V 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 = 50 Ω, V
CC = +3.0V, f RFIN = 2450MHz, R BIAS = 1.2k Ω, 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 = 750 Ω
R BIAS = 1.2k Ω
R BIAS = 3.9k Ω
IIP3 vs. R
BIAS
MAX2644 toc11
-9
-8
-6
-7
-3
-2
-4
-5
-1
IIP3 (dBm)
0.5 1.5 2.0 1.0 2.5 3.0 3.5 4.0
R BIAS (k Ω)
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 2.0 1.0 2.5 3.0 3.5 4.0
R BIAS (k Ω)
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
1.2k Ω
6
5
4
V CC
GND
C3
2.2pF
Length = 400mils
C2
33pF
VCC
GND
RFIN
GND
RFOUT BIAS
GAIN: 17dB
IIP3: -3dBm
Figure 1. High Gain Design