19-1667; Rev 0; 4/00
1.8GHz to 2.5GHz Direct Downconversion
Receivers
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.
o
Input Frequency Range
1.8GHz to 2.1GHz (MAX2700)
2.1GHz to 2.5GHz (MAX2701)
o
Cascaded Performance at 1960 MHz
3.5dB Noise Figure
-7.5dBm Input IP3 at Maximum Gain
o
LNA with Selectable Gain and Shutdown Option
o
High Linearity Direct I/Q Downconverter
o
Wideband LO Quadrature Generator
o
3dB Baseband Channel Bandwidth of At Least
56MHz
o
Variable Gain Baseband Amplifiers with >60dB
Control Range
o
Baseband Gain Offset Correction Loop
o
+2.7V to +3.3V Single-Supply Operation
o
Small 48-pin TQFP-EP Package
Features
MAX2700/MAX2701
Ordering Information
PART
MAX2700ECM
MAX2701ECM
TEMP. RANGE
-40°C to 85°C
-40°C to 85°C
PIN-PACKAGE
48 TQFP-EP
48 TQFP-EP
Pin Configuration
TOP VIEW
IIN1+
IIN1-
DCI1+
DCI1-
IOUT1
43
42
41
40
39
V
CC
LO
GND
MIX_I
GND
48
47
46
45
44
38
37
IIN2+
V
CC
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
36
35
34
33
32
31
30
29
28
27
26
25
________________________Applications
Wireless Local Loop
Wideband Direct-Sequence Spread-Spectrum
Systems
Two-Way MMDS
Wideband 2.4GHz ISM Radios
Digital Microwave Radios
MAX2700
MAX2701
IIN2-
DCI2+
DCI2-
IOUT2
GND
RFIN-
RFIN+
V
CC
QOUT2
DCQ2-
DCQ2+
QIN2-
________________________________________________________________
Maxim Integrated Products
GND
LNAOUT
GND
MIX_Q
V
CC
QIN1+
QIN1-
DCQ1+
DCQ1-
QOUT1
MIXTNK
QIN2+
TQFP-EP
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.
1.8GHz to 2.5GHz Direct Downconversion
Receivers
MAX2700/MAX2701
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ..............................................................-0.3V to +6V
RF Signals
P
RFIN
, P
LNAIN
, P
LO
.....................................................+15dBm
Baseband Signals
IIN1+ to IIN1-, IIN2+ to IIN2-,
QIN1+ to QIN1-, QIN2+ to QIN2- ......................................±2V
Input Voltages
AGC, GAIN_SET,
SHDN, X2_EN,
CEXT_, RFIN_, LO, LNAIN, IIN_ _,
QIN_ _ , DCI_ _ , DCQ_ _ to GND ..........-0.3V to (V
CC
+ 0.3V)
Input Current
AGC……………………………………………………..±50mA
All Digital Inputs………………………………………..±10mA
Continuous Power Dissipation (T
A
= +70°C)
48-Pin TQFP-EP (derate 27mW/°C above +70°C) .....2000mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
DC ELECTRICAL CHARACTERISTICS
(MAX2700/MAX2701 EV kit (Figure 3), V
CC
= +2.7V to +3.3V,
SHDN
= GAIN_SET = V
CC
,
X2_EN
= GND, V
AGC
= 1.25V, CEXT+ con-
nected to CEXT-; no RF input signals applied; RFIN, LNAIN, LO inputs are terminated with 50Ω, LNAOUT connected to V
CC
through a
10nH inductor; MIX_I, MIX_Q, QIN1+, QIN1-, QOUT1, IIN1+, IIN1-, IOUT1, QIN2+, QIN2-, QOUT2, IIN2+, IIN2-, IOUT2 pins are
unconnected; T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
CC
= +3.0V, T
A
= +25°C.)
PARAMETERS
SUPPLY
Supply Voltage
LNA
enabled
T
A
= +25°C
Operating Supply Current
LNA
enabled
T
A
= -40°C to +85°C
LNA
disabled
LNA
disabled
MAX2700
MAX2701
MAX2700
MAX2701
MAX2700
MAX2701
MAX2700
MAX2701
20
2
0.6
SHDN, X2_EN,
GAIN_SET
Input Bias Current
AGC, +0.5 < V
AGC
< +2.0V
AGC, V
AGC
= 0.5V,
SHDN
= GND
MIX_I, MIX_Q
DC Output Voltage
IOUT1, QOUT1
IOUT2, QOUT2
-1
-22
-2
1.2
1.1
1.25
V
0.5
12
2
µA
2.7
165
167
155
156
3.3
215
220
200
205
230
235
210
215
100
µA
V
V
mA
V
CONDITIONS
MIN
TYP
MAX
UNITS
Shutdown Supply Current
CONTROL INPUTS/OUTPUTS
Input Logic Voltage High
Input Logic Voltage Low
SHDN
= GND, V
AGC
= 0.5V
2
_______________________________________________________________________________________
1.8GHz to 2.5GHz Direct Downconversion
Receivers
AC ELECTRICAL CHARACTERISTICS
(MAX2700/MAX2701 EV kit (Figure 3), V
CC
= +3.0V, T
A
= +25°C,
SHDN
= GAIN_SET = V
CC
,
X2_EN
= GND, CEXT+ connected to
CEXT-, P
LO
= -13dBm, F
LO
= 980MHz (MAX2700) and 1200MHz (MAX2701), P
LNAIN
= -30dBm, P
RFIN
= -25dBm, LNAIN and RFIN
(single-ended input to balun) driven from 50Ω source, LNAOUT terminated into load; MIX_I, MIX_Q AC-coupled to 2kΩ load; IIN1+,
QIN1+, IIN2+, QIN2+ driven from 1.1kΩ AC-coupled source; IOUT1, QOUT1 AC-coupled to 2kΩ; IOUT2, QOUT2 AC-coupled to
100Ω; input to VGAs, 20mVp-p at 1MHz tone, set V
AGC
= 1.25V, unless otherwise noted.)
PARAMETERS
LNA STAGE
Operating Frequency Range
(Note 1)
MAX2700
MAX2701
MAX2700,
f
LNAIN
= 1960MHz
T
A
= -40°C to 85°C
Power Gain (Note 2)
MAX2701,
f
LNAIN
= 2400MHz
T
A
= -40°C to 85°C
MAX2700,
f
LNAIN
= 1960MHz
MAX2701,
f
LNAIN
= 2400MHz
Input Third-Order Intercept
(Note 3)
Reverse Isolation
Isolation
MAX2700,
f
LNAIN
= 1960MHz
MAX2701,
f
LNAIN
= 2400MHz
GAIN_SET = V
CC
GAIN_SET = GND
GAIN_SET = V
CC
GAIN_SET = GND
GAIN_SET = V
CC
GAIN_SET = GND
GAIN_SET = V
CC
GAIN_SET = GND
GAIN_SET = V
CC
GAIN_SET = GND
GAIN_SET = V
CC
GAIN_SET = GND
GAIN_SET = V
CC
GAIN_SET = GND
GAIN_SET = V
CC
GAIN_SET = GND
1800
2100
13.5
-7.5
13
-8
13
-6
12.5
-6.5
2.0
15.8
2.3
16.7
+2.7
+5.1
+3.8
+4.3
28
30
44
1.1
1.8
1.3
2.1
1.7
1.6
1.2
1.4
1800
2100
16
14.5
19.3
18.1
11.0
12.8
2100
2500
21.5
20
−
dB
dB
dBm
dB
16.5
-1.8
17.1
-1.9
2100
2500
19.5
2
20
2.5
18.5
0.5
19
1.0
dB
MHz
CONDITIONS
MIN
TYP
MAX
UNITS
MAX2700/MAX2701
Noise Figure
1800MHz to 2500MHz, GAIN_SET = V
CC
or GND
LNAIN to LO, f
LNAIN
= 1800MHz to 2500MHz
LNAOUT to RFIN, f
LNAIN
= 1800 MHz to 2500 MHz
MAX2700 GAIN_SET = V
CC
At LNA input, with external
matching circuit at LNAIN
GAIN_SET = GND
MAX2701 GAIN_SET = V
CC
GAIN_SET = GND
MAX2700 GAIN_SET = V
CC
At LNA output, with external
matching circuit at LNAOUT
GAIN_SET = GND
MAX2701 GAIN_SET = V
CC
GAIN_SET = GND
VSWR
MIXER STAGE
(Differential RF input to mixer I/Q outputs with external balun and matching circuit to 50Ω)
Frequency Range
(Notes 1, 2)
Voltage Gain
DSB Noise Figure
MAX2700
MAX2701
MAX2700, f
RFIN
= 1960 MHz
MAX2701, f
RFIN
= 2400 MHz
MAX2700, f
RFIN
= 1960MHz
MAX2701, f
RFIN
= 2400MHz
MHz
dB
dB
_______________________________________________________________________________________
3
1.8GHz to 2.5GHz Direct Downconversion
Receivers
MAX2700/MAX2701
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2700/MAX2701 EV kit (Figure 3), V
CC
= +3.0V, T
A
= +25°C,
SHDN
= GAIN_SET = V
CC
,
X2_EN
= GND, CEXT+ connected to
CEXT-, P
LO
= -13dBm, F
LO
= 980MHz (MAX2700) and 1200MHz (MAX2701), P
LNAIN
= -30dBm, P
RFIN
= -25dBm, LNAIN and RFIN
(single-ended input to balun) driven from 50Ω source, LNAOUT terminated into load; MIX_I, MIX_Q AC-coupled to 2kΩ load; IIN1+,
QIN1+, IIN2+, QIN2+ driven from 1.1kΩ AC-coupled source; IOUT1, QOUT1 AC-coupled to 2kΩ; IOUT2, QOUT2 AC-coupled to
100Ω; input to VGAs, 20mVp-p at 1MHz tone, set V
AGC
= 1.25V, unless otherwise noted.)
PARAMETERS
Input Third-Order Intercept
(Note 4)
Input Second-Order Intercept
(Note 5)
VSWR
CONDITIONS
MAX2700, f
LO
= 980MHz
MAX2701, f
LO
= 1200MHz
MAX2700
MAX2701
With 50Ω external
matching at RFIN+/ RFIN-
MAX2700
Isolation (RFIN to MIX_I/Q)
MAX2701
MAX2700
MAX2701
f
RFIN
= 1800MHz to
2100MHz
f
RFIN
≤20MHz
f
RFIN
= 2100MHz to
2500MHz
f
RFIN
≤20MHz
Isolation (RFIN to LO)
MAX2700, f
RFIN
= 1800MHz to 2100MHz
MAX2701, f
RFIN
= 2100MHz to 2500MHz
f
LO
= 900MHz to
1050MHz,
X2_EN
= GND
MAX2700
f
LO
= 900MHz to
1050MHz,
X2_EN
= GND,
isolation at 2 x F
LO
f
LO
= 1800MHz to
2100MHz,
X2_EN
= V
CC
f
LO
= 1050MHz to 1250MHz,
X2_EN
= GND
MAX2701
f
LO
= 1050MHz to 1250MHz,
X2_EN
= GND, isolation at
2 x F
LO
f
LO
= 2100MHz to
2500MHz,
X2_EN
= V
CC
Mixer Spurious Suppression
Baseband Bandwidth
2 x LO - RF (Note 6)
MIX_I/Q
-1dB bandwidth (Note 2)
-3dB bandwidth
Baseband frequency =
125kHz
Up to -1dB baseband
width (Note 2)
37
MIN
TYP
+6.3
+6.5
+28.3
+38
1.5
1.2
35
28
22
12
38
45
49
dB
dB
MAX
UNITS
dBm
dBm
–
43
dB
33
60
Isolation (LO to RFIN)
44
70
60
69
170
0.1
0
0.7
dB
0.7
dBc
MHz
Gain Mismatch
∆G
V
(I-Q) (between mixer
I and Q channels)
4
_______________________________________________________________________________________
1.8GHz to 2.5GHz Direct Downconversion
Receivers
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2700/MAX2701 EV kit (Figure 3), V
CC
= +3.0V, T
A
= +25°C,
SHDN
= GAIN_SET = V
CC
,
X2_EN
= GND, CEXT+ connected to
CEXT-, P
LO
= -13dBm, F
LO
= 980MHz (MAX2700) and 1200MHz (MAX2701), P
LNAIN
= -30dBm, P
RFIN
= -25dBm, LNAIN and RFIN
(single-ended input to balun) driven from 50Ω source, LNAOUT terminated into load; MIX_I, MIX_Q AC-coupled to 2kΩ load; IIN1+,
QIN1+, IIN2+, QIN2+ driven from 1.1kΩ AC-coupled source; IOUT1, QOUT1 AC-coupled to 2kΩ; IOUT2, QOUT2 AC-coupled to
100Ω; input to VGAs, 20mVp-p at 1MHz tone, set V
AGC
= 1.25V, unless otherwise noted.)
PARAMETERS
Group Delay
Differential Group Delay
(Note 2)
Output Impedance
Mixer Output Level
(Note 2)
CONDITIONS
t
gd
, RFIN to MIX_I/Q, frequency up to
-1dB baseband width
∆t
gd
(between mixer I and Q channels)
Z
out
, MIX_I, MIX_Q, frequency up to -1dB baseband
width
MIX_I, MIX_Q, baseband output at -1dB compression
point
1.4
1.4
2.1
MIN
TYP
1.8
1
MAX
UNITS
ns
ns
Ω
Vp-p
MAX2700/MAX2701
LO DOUBLER, LO BUFFER, QUADRATURE GENERATOR
X2_EN
= GND
LO Frequency Range
(Notes 1, 2)
LO Input Power (Note 7)
X2_EN
= V
CC
X2_EN
= V
CC
or GND
f
LO
= 900MHz to
1050MHz,
X2_EN
= GND
MAX2700
LO VSWR
MAX2701
f
LO
= 2100MHz to
2500MHz,
X2_EN
= V
CC
Quadrature Error
∆φ ,
MIX_I to MIX_Q
-1dB bandwidth (Note 2)
-3dB bandwidth
IIN1+, IIN1-, QIN1+, QIN1-, single-ended
Between IIN1+ and QIN1+
V
AGC
= 0.5V
V
AGC
= 2.0V
Mismatch between IIN1 to IOUT1 and QIN1 to QOUT1,
0.5V < V
AGC
< 2 V
Guaranteed Monotonic over 0.5V <V
AGC
< 2V,
V
AGC
= 1.25V
Z
S
= 1.1kΩ (Note 8)
For 10dB of gain (with AGC)
V
AGC
= 2.0V
V
AGC
= 0.5V
-1.5
37
14
BASEBAND STAGE 1 (IIN1 TO IOUT1, QIN1 TO QOUT1)
Channel Bandwidth
Input Impedance
Input Impedance Mismatch
Voltage Gain (G
V
)
Voltage Gain Mismatch
VGA1 Gain Slope
Noise Figure
Phase Shift (Note 2)
26
56
1.9
4
2.2
40
0.2
34
7.5
34
0.5
0.9
6
42
MHz
kΩ
Ω
dB
dB
dB/V
dB
degrees
2.0
1.5
4.5
degrees
f
LO
= 1800MHz to
2100MHz,
X2_EN
= V
CC
f
LO
= 1050MHz to
1250MHz,
X2_EN
= GND
1.8
−
1.7
MAX2700
MAX2701
MAX2700
MAX2701
900
1050
1800
2100
-16
-13
2.0
1050
1250
2100
2500
-10
dBm
MHz
_______________________________________________________________________________________
5
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