User Manual

General Description
The MAX2700/MAX2701 are highly integrated direct
downconversion (zero-IF) receivers designed for wide-
band wireless local loop (WLL) systems operating in
the 1.8GHz to 2.5GHz band. The MAX2700/MAX2701s’
zero-IF architecture eliminates the need for IF down-
conversion stages and the use of an IF SAW filter. This
reduces the overall receiver cost by reducing the com-
ponent count and required board space.
The MAX2700/MAX2701 have three main blocks: low-
noise amplifier (LNA), quadrature downconverter, and
baseband variable gain amplifiers (VGAs). The LNA is
a single-ended amplifier with selectable gain and shut-
down options. It provides a high input third-order inter-
cept point (IP3), which reduces cross-modulation and
gain compression due to high-level RF interference.
The quadrature downconverter section consists of two
highly linear double-balanced mixers driven by an
external local oscillator (LO) with a selectable LO dou-
bler. The double-balanced mixers are optimized to pro-
vide high input IP3 and minimum added noise. The
mixers’ high input second-order intercept point (IIP2)
helps minimize receiver desensitization due to high-
level AM-modulated interferers.
The two baseband VGAs in each channel provide 80dB
of total maximum gain and greater than 60dB of gain
control. The first AGC amplifier is optimized for low
noise, low power dissipation, and high linearity over the
entire gain range to ensure high gain compression per-
formance. An external lowpass filter between baseband
VGAs provides the required channel selectivity at the
adjacent channel. An integrated gain offset correction
loop circuit provides <0.3dB amplitude mismatch
between the I and Q channels.
The MAX2700/MAX2701 operate from a single +2.7V to
+3.3V power supply, drawing only 165mA of supply
current and 20µA in shutdown mode. Both devices are
available in small 48-pin TQFP packages with exposed
paddle (EP) for optimum high-frequency performance.
________________________Applications
Wireless Local Loop
Wideband Direct-Sequence Spread-Spectrum
Systems
Two-Way MMDS
Wideband 2.4GHz ISM Radios
Digital Microwave Radios
Features
♦ Input Frequency Range
1.8GHz to 2.1GHz (MAX2700)
2.1GHz to 2.5GHz (MAX2701)
♦ Cascaded Performance at 1960 MHz
3.5dB Noise Figure
-7.5dBm Input IP3 at Maximum Gain
♦ LNA with Selectable Gain and Shutdown Option
♦ High Linearity Direct I/Q Downconverter
♦ Wideband LO Quadrature Generator
♦ 3dB Baseband Channel Bandwidth of At Least
56MHz
♦ Variable Gain Baseband Amplifiers with >60dB
Control Range
♦ Baseband Gain Offset Correction Loop
♦ +2.7V to +3.3V Single-Supply Operation
♦ Small 48-pin TQFP-EP Package
MAX2700/MAX2701
1.8GHz to 2.5GHz Direct Downconversion
Receivers
________________________________________________________________ Maxim Integrated Products 1
IIN2-
DCI2+
DCI2-
IOUT2
GND
RFIN-
RFIN+
V
CC
QOUT2
DCQ2-
DCQ2+
QIN2-
CEXT-
CEXT+
V
CC
X2_EN
GND
LNAIN
GND
GND
GAIN_SET
SHDN
AGC
V
CC
1
2
3
4
5
6
7
8
9
10
11
12
13 14 15 16 17 18 19 20 21 22 23 24
48 47 46 45 44 43 42 41 40 39 38 37
36
35
34
33
32
31
30
29
28
27
26
25
GND
LNAOUT
GND
MIX_Q
V
CC
QIN1+
QIN1-
DCQ1+
DCQ1-
QOUT1
MIXTNK
QIN2+
V
CC
LO GND MIX_I GND IIN1+ IIN1- DCI1+ DCI1- IOUT1 V
CC
IIN2+
TQFP-EP
MAX2700
MAX2701
TOP VIEW
Pin Configuration
19-1667; Rev 0; 4/00
For free samples and the latest literature, visit www.maxim-ic.com or phone [phone].
For small orders, phone [phone].
Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
MAX2700ECM -40°C to 85°C 48 TQFP-EP
MAX2701ECM -40°C to 85°C 48 TQFP-EP