19-1759; Rev 0; 7/00
ANUAL
N KIT M EET
ATIO
SH
EVALU
S DATA
OLLOW
F
3.4GHz to 3.8GHz SiGe
Low-Noise Amplifier/PA Predriver
Features
o
3.4GHz to 3.8GHz Frequency Range
o
LNA Performance (High/Low-Gain Modes)
Gain: +14.4dB/-9.7dB
NF: 2.3dB/15.5dB
Input IP3: +4dBm/+13dBm
Supply Current: 9.2mA/2.7mA
o
Highly Versatile Application
Receive Path 1st and 2nd Stage LNA
Transmit PA Predriver
LO Buffer
o
Adjustable IP3 and Supply Current
o
0.1碌A Supply Current in Shutdown Mode
o
+3.0V to +5.5V Single-Supply Operation
o
10-Pin 碌MAX-EP Package (5.0mm x 3.0mm)
General Description
The MAX2645 is a versatile, high-linearity, low-noise
amplifier designed for 3.4GHz to 3.8GHz wireless local
loop (WLL), wireless broadband access, and digital
microwave radio applications. The device features an
externally adjustable bias control, set with a single resis-
tor, that allows the user to meet minimum linearity require-
ments while minimizing current consumption. The
amplifier鈥檚 high-gain, low-noise performance and
adjustable input third-order intercept (IP3) allow it to be
used as a low-noise amplifier (LNA) in the receive path, a
PA predriver in the transmit path, or as an LO buffer.
The MAX2645 features a logic-level gain control that pro-
vides a 25dB step reduction in gain, which improves IP3
performance for operation during high input signal level
conditions. Supply current is reduced from 9mA in high-
gain mode to 3mA in low-gain mode. The device also
includes a logic-controlled shutdown mode, which
reduces supply current to 0.1碌A. The MAX2645 operates
from a +3V to +5.5V supply and is offered in the miniature
10-pin 碌MAX package (5mm
鉁?/div>
3mm) with an exposed
paddle. Its performance has been optimized for use with
the MAX2683/MAX2684 3.5GHz SiGe mixers to provide a
complete high-performance, front-end solution for 3.5GHz
applications.
MAX2645
Ordering Information
PART
MAX2645EUB
TEMP. RANGE
-40掳C to +85掳C
PIN-PACKAGE
10
碌MAX-EP*
Applications
Wireless Local Loop
Wireless Broadband Access
Digital Microwave Radios
*Exposed paddle
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
RADIAL STUB
V
CC
APPLICATION
CIRCUIT
LNA, LOW NF
LNA, HIGH IP3
PA PREDRIVER
GAIN
(dB)
14.4/-9.7
14.9/-10.7
15.2/-9.7
NF
(dB)
2.3/15.5
2.6/16
2.6/16
IIP3
(dBm)
+4/+13
+10/+15.5
+11.8/+16.2
LOGIC
INPUTS
GAIN STEP
SHUTDOWN
R
BIAS
BIAS AND POWER
MANAGEMENT
T
LINE
MAX2645
RF
INPUT
3.5GHz
Z1
C1
RFIN
HIGH
GAIN
LOW
GAIN
RF
OUTPUT
GND
________________________________________________________________
Maxim Integrated Products
1
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.
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