MAXIM MAX2102

19-1256; Rev 2; 10/98
NUAL
KIT MA
ATION
U
EET
L
H
A
S
V
E
S DATA
W
O
L
L
FO
Direct-Conversion Tuner ICs for
Digital DBS Applications
The MAX2102 features an AGC range of 50dB, allowing
input power levels as low as -69dBm. The MAX2105
has a reduced AGC range of 41dB and accepts input
power levels down to -60dBm. The reduced AGC range
of the MAX2105 allows the use of a high-gain external
LNA to achieve a lower system noise figure (NF).
____________________________Features
♦ Low-Cost Bipolar Design, Lowest Cost
Architecture
♦ Operate from a Single +5V Supply
♦ 950MHz to 2150MHz Input Frequency Range*
♦ On-Chip Quadrature Generator, Dual-Modulus
Prescaler (/64, /65)
♦ Input Levels
-69dBm to -19dBm per Carrier (MAX2102)
-60dBm to -19dBm per Carrier (MAX2105)
♦ Over 50dB AGC Control Range (MAX2102)
♦ Noise Figure = 13.2dB (MAX2102);
IP3 = 6.5dBm (at 1450MHz)
♦ Automatic Baseband Offset Correction
♦ Easy Interface to MAX1002/MAX1003 Dual ADC
and Popular Baseband ICs
Ordering Information
________________________Applications
DBS Tuners
Wireless Local Loop
DVB-Compliant DBS Tuners
Broadband Systems
Cellular Base Stations
LMDS
TEMP. RANGE
PART
PIN-PACKAGE
MAX2102CWI
0°C to +70°C
28 SO
MAX2105CWI
0°C to +70°C
28 SO
Functional Diagram
VCC
QOUT
14
13
GND
12
GND
11
AGC
10
GND
RFIN
RFIN
VCC
GND
VCC
GND
IOUT
VCC
9
8
7
6
5
4
3
2
1
Q
I
90°
MAX2102
MAX2105
/64, /65
0°
OFFSET CORRECTION
15
QDC
16
QDC
17
IDC
18
IDC
19
GND
20
VCC
21
LO
22
LO
23
VCC
24
GND
25
26
27
PSGND
PSOUT
MOD
28
VCC
†Patents pending
*Contact factory for MAX2102/MAX2105 versions with expanded frequency range.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX2102/MAX2105
General Description
The MAX2102/MAX2105† are low-cost direct-conversion tuner ICs designed for use in digital direct-broadcast satellite (DBS) television set-top box units. The
direct-conversion architecture reduces system cost
compared to devices with IF-based architectures.
The MAX2102/MAX2105 directly tune L-band signals to
baseband using a broadband I/Q downconverter.
Operating frequency range spans from at least 950MHz
to 2150MHz.
The ICs include a low-noise amplifier (LNA) with automatic gain control (AGC), two downconverter mixers,
an oscillator buffer with 90° quadrature generator and
prescaler, and baseband amplifiers.
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
ABSOLUTE MAXIMUM RATINGS
VCC to GND ..............................................................-0.5V to +7V
RFIN to RFIN ..........................................................................±2V
LO to LO ................................................................................±2V
AGC, MOD, RFIN, RFIN, LO, LO to GND.....-0.5V to (VCC + 0.5V)
AGC Current. ....................................................................±30mA
IDC to IDC, QDC to QDC.......................................................±2V
IOUT or QOUT to GND Short-Circuit Duration ...................10sec
PSOUT to GND Short-Circuit Duration.................................None
IDC, IDC, QDC, QDC to GND ....................-0.5V to (VCC + 0.5V)
Continuous Power Dissipation (TA = +70°C)
SO (derate 12.5mW/°C above +70°C) ..........................1.025W
Operating Temperature Range...............................0°C to +70°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+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
(VCC = +4.75V to +5.25V; GND = 0V; PSGND = GND; AGC = 1.3V; MOD = 0.8V; PRFIN = OFF, fLO = 1450.125MHz; PLO = -15dBm;
IOUT, QOUT = open; TA = 0°C to +70°C; unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
5.25
V
195
mA
0.8
V
-80
10
µA
SUPPLY
Operating Supply Voltage Range
4.75
Quiescent Supply Current
150
CONTROL INPUTS, PRESCALER
MOD Input Low Level
MOD Input High Level
2.0
V
MOD Input Bias Current
0V ≤ VMOD ≤ VCC
AGC Input Bias Current
AGC Input Bias Current
MAX2102
0.5V ≤ VAGC ≤ 4V
-250
180
MAX2105
1V ≤ VAGC ≤ 4V
-180
180
2.2
2.6
IOUT, QOUT Common-Mode Voltage
µA
V
AC ELECTRICAL CHARACTERISTICS
(MAX2102 EV kit circuit (Figure 1); V CC = +5V; PSGND = open; MOD = GND; f RFIN = 2150MHz; P RFIN = -19dBm; f LO =
2150.125MHz; PLO = -15dBm driven single-ended into LO; AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p; IOUT, QOUT drive
AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; TA = +25°C; unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
2150
MHz
RF FRONT END
RFIN Carrier Frequency Range
(Note 1)
950
RFIN Maximum Single-Carrier
Input Power
Refers to single-carrier power generating
VIOUT = VQOUT = 0.5Vp-p,
950MHz < fRFIN < 2150MHz,
950MHz < fLO < 2150MHz (Note 2)
-19
RFIN Minimum Single-Carrier
Input Power
Refers to single-carrier power generating
VIOUT = VQOUT = 0.5Vp-p,
950MHz < fRFIN < 2150MHz,
950MHz < fLO < 2150MHz (Note 2)
MAX2102
-69
MAX2105
-60
0.5V ≤ VAGC ≤ 4V
MAX2102
50
1V ≤ VAGC ≤ 4V
MAX2105
41
AGC Range
2
dBm
dBm
_______________________________________________________________________________________
dB
Direct-Conversion Tuner ICs for
Digital DBS Applications
(MAX2102 EV kit circuit (Figure 1); V CC = +5V; PSGND = open; MOD = GND; f RFIN = 2150MHz; P RFIN = -19dBm; f LO =
2150.125MHz; PLO = -15dBm driven single-ended into LO; AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p; IOUT, QOUT drive
AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; TA = +25°C; unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
RFIN Input Third-Order Intercept
PRFIN = -19dBm per tone, AGC set via servo loop for
VIOUT = VQOUT = 0.5Vp-p per tone,
f1RFIN = 1448.1MHz, f2RFIN = 1449MHz,
fLO = 1451MHz
6.5
dBm
RFIN Input Second-Order Intercept
PRFIN = -19dBm per tone, AGC set via servo loop for
VIOUT = VQOUT = 0.5Vp-p per tone,
f1RFIN = 1200MHz, f2RFIN = 2150MHz,
fLO = 951MHz
15.1
dBm
fRFIN = 1441MHz,
fLO = 1451MHz
Noise Figure
fRFIN = 2141MHz,
fLO = 2151MHz
PRFIN = -69dBm
MAX2102
13.2
PRFIN = -60dBm
MAX2105
15.7
PRFIN = -69dBm
MAX2102
12.9
PRFIN = -60dBm
MAX2105
15.5
AGC = 4V,
MAX2102
PRFIN set via servo
loop for VIOUT =
MAX2105
VQOUT = 0.5Vp-p
Defined as ∆NF/∆Gain; for AGC range,
Maximum Noise-Figure Variation with defined as single-carrier power range
AGC Gain Setting
of -69dBm to -59dBm (MAX2102) or
-60dBm to -50dBm (MAX2105)
11.2
11.5
MAX2102
-0.5
MAX2105
-0.7
dB/dB
RFIN Worst-Case VSWR across
Band
fRFIN = 950MHz to 2150MHz, 50Ω source
2.3:1
Maximum Power of Spurious
Downconversion Products
950MHz < fRFIN < 2150MHz, 950MHz < fLO <
2150MHz. Dominated by LO second-harmonic power
causing downconversion of unwanted channel. Test
conditions: fLO = 1075.5MHz, fRFIN = 2150MHz,
PRFIN = -69dBm (MAX2102) or -60dBm (MAX2105)
-32.3
LO Leakage at RFIN
dB
dBc
PLO = -15dBm, 950MHz < fLO < 2150MHz (Note 3)
-49
PLO = -15dBm, P LO = -15dBm (differentially driven),
950MHz < fLO < 2150MHz (Note 3)
-54
dBm
_______________________________________________________________________________________
3
MAX2102/MAX2105
AC ELECTRICAL CHARACTERISTICS
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2102 EV kit circuit (Figure 1); V CC = +5V; PSGND = open; MOD = GND; f RFIN = 2150MHz; P RFIN = -19dBm; f LO =
2150.125MHz; PLO = -15dBm driven single-ended into LO; AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p; IOUT, QOUT drive
AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; TA = +25°C; unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
2150
MHz
OSCILLATOR BUFFER, QUADRATURE GENERATOR, PRESCALER
LO Input Frequency Range
(Note 1)
950
LO Input Worst-Case VSWR over
Band
fLO = 950MHz to 2150MHz, 50Ω source into
MAX2102 EV kit match circuit
1.75:1
(Note 4)
-15
Refers to power level driven into LO,
LO (differentially driven) (Notes 2, 4)
-15
RFIN to LO Input Isolation
(Notes 2, 5)
28
IOUT, QOUT Phase Imbalance
950MHz < fRFIN < 2150MHz;
950MHz < fLO < 2150MHz; PRFIN = -40dBm;
fIOUT, fQOUT = 125kHz (Note 2)
LO Input Power Level
Worst-Case Additional Phase
Imbalance Over Temperature
-5
dBm
dB
3
TA = +25°C to +70°C (Notes 2 and 6)
-0.1
0.6
TA = +25°C to +0°C (Note 2)
-0.07
1
IOUT, QOUT Amplitude Imbalance
950MHz < fRFIN < 2150MHz;
950MHz < fLO < 2150MHz; PRFIN = -40dBm;
fIOUT, fQOUT = 125kHz (Note 2)
Prescaler Divide Ratio
TA = 0°C to +70°C
(Note 2)
Prescaler Output Swing at PSOUT
2kΩ || 10pF load
0.8
Prescaler Duty Cycle at PSOUT
PSOUT load = 2kΩ || 5pF (Note 3)
35
0.5
MOD = low
64
64
MOD = high
65
65
degrees
degrees
dB
Vp-p
65
%
BASEBAND AC CHARACTERISTICS
IOUT, QOUT Clipping Level
PRFIN = -50dBm; AGC = 4V, VCC = 5.0V
2.7
Vp-p
Baseband Bandwidth
(at IOUT, QOUT)
At -3dB attenuation
94
MHz
Baseband Gain Ripple
(at IOUT, QOUT)
1kHz < (fIOUT, fQOUT) < 25MHz, 950MHz < fRFIN <
2150MHz, 950MHz < fLO < 2150MHz (Notes 3, 7, 8)
0.45
Baseband Group Delay Ripple
(at IOUT, QOUT)
1kHz < (fIOUT, fQOUT) < 25MHz, 950MHz < fRFIN <
2150MHz, 950MHz < fLO < 2150MHz (Notes 3, 7, 8)
0.45
4
_______________________________________________________________________________________
0.85
dB
ns
Direct-Conversion Tuner ICs for
Digital DBS Applications
(MAX2102 EV kit circuit (Figure 1); V CC = +5V; PSGND = open; MOD = GND; f RFIN = 2150MHz; P RFIN = -19dBm; f LO =
2150.125MHz; PLO = -15dBm driven single-ended into LO; AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p; IOUT, QOUT drive
AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; TA = +25°C; unless otherwise noted.)
TYP
MAX
UNITS
IOUT, QOUT Output Impedance
PARAMETER
(Note 3)
CONDITIONS
MIN
4.7
10
Ω
Maximum IOUT to QOUT Output
Impedance Difference
(Note 3)
±1
Ω
Power-Supply Ripple Rejection
(measured at IOUT, QOUT)
VCC = 5V + 50mVp-p at 300kHz. Amplitude of
300kHz relative to 500mVp-p measured at IOUT,
QOUT. Measured using MAX2102 EV kit.
32
dB
Note 1: All specifications with guaranteed min/max limits are met within this frequency range. Contact factory for
MAX2102/MAX2105 versions with expanded frequency range.
Note 2: Guaranteed by production test and/or design and characterization.
Note 3: Guaranteed by design and characterization.
Note 4: IOUT, QOUT Phase and Amplitude Imbalance specifications are met within this LO power range.
Note 5: Tested under two conditions: 1) Normal test: PRFIN = -20dBm, and 2) Overdrive test: PRFIN = -5dBm but AGC set via servo
loop for VIOUT = VQOUT = 0.5Vp-p for PRFIN = -30dBm.
Note 6: Negative numbers (-0.1°) indicate improvement in quadrature accuracy with increasing temperature.
Note 7: Includes contribution from front-end gain tilt and delay variations produced by varying fRFIN by ±30MHz.
Note 8: 1kHz minimum frequency determined by 0.22µF offset-correction capacitors. Different value capacitors yield proportionally
different low-frequency cutoffs. Group delay at low frequencies will also be affected. See Applications Information section.
__________________________________________Typical Operating Characteristics
(MAX2102 EV kit circuit (Figure 1), VCC = 5V, PSGND = open, MOD = GND, fRFIN = 2150MHz, PRFIN = -19dBm, fLO = 2150.125MHz,
PLO = -15dBm driven single-ended into LO, AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p, IOUT, QOUT drive AC-coupled
100Ω loads, 2kΩ from PSOUT to GND, TA = +25°C, unless otherwise noted.)
160
TA = +25°C
150
140
TA = 0°C
130
120
4.75
4.85
5.00
5.15
SUPPLY VOLTAGE (V)
5.25
-10
AGC = 1V
TA = +70°C
TA = +25°C
TA = 0°C
-20
-30
AGC RANGE
-40
-50
TA = +70°C
TA = +25°C
-60
TA = 0°C
AGC = 4V
-70
MAX2102/05-02
MAX2102/05-01
TA = +70°C
0
0
SINGLE CARRIER POWER FOR 0.5Vp-p
BASEBAND LEVEL (dBm)
SUPPLY CURRENT (mA)
170
PSGND = GND
(PRESCALER ENABLED)
SINGLE-CARRIER POWER FOR 0.5Vp-p
BASEBAND LEVEL (dBm)
180
MAX2105
AGC RANGE vs. FREQUENCY
MAX2102
AGC RANGE vs. FREQUENCY
-10
TA = 0°C
-20
TA = +25°C
TA = +70°C
MAX2102/05-01insert
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
AGC = 1V
-30
-40
TA = +25°C
-50
TA = +70°C
-60
AGC = 4V
-70
TA = 0°C
-80
-80
0.8
1.0
1.2
1.4
1.6
1.8
RFIN FREQUENCY (GHz)
2.0
2.2
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
RFIN FREQUENCY (GHz)
_______________________________________________________________________________________
5
MAX2102/MAX2105
AC ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(MAX2102 EV kit circuit (Figure 1), VCC = 5V, PSGND = open, MOD = GND, fRFIN = 2150MHz, PRFIN = -19dBm, fLO = 2150.125MHz,
PLO = -15dBm driven single-ended into LO, AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p, IOUT, QOUT drive AC-coupled
100Ω loads, 2kΩ from PSOUT to GND, TA = +25°C, unless otherwise noted.)
TA = +25°C
-60
TA = 0°C
-20
-30
TA = +70°C
-40
TA = +25°C
-50
TA = 0°C
1.6
2.0
2.4
+70°C NF (dB)
0.8
4.0
15.7
+25°C NF (dB)
15.3
15.1
25
0°C NF (dB)
TA = +25°C
17
16
13
-55
-60
-65
-70
fLO = 1441MHz
22
21
TA = +70°C
17
16
-65
-70
RFIN CARRIER LEVEL (dBm)
-75
INPUT-REFERRED IP3 vs. FREQUENCY
9
TA = 0°C
8
TA = +25°C
7
6
5
TA = +70°C
4
f1 = fLO - 2MHz
f2 = fLO - 2.9MHz
PRFIN = -19dBm PER TONE
AGC SET VIA SERVO LOOP
FOR 0.5Vp-p PER TONE
3
TA = 0°C
14
2
13
1
12
-60
-65
-60
10
INPUT IP3 (dBm)
NOISE FIGURE (dB)
18
15
TA = 0°C
-55
RFIN CARRIER LEVEL (dBm)
TA = +25°C
19
-50
-75
MAX2102/05-05insert
23
MAX2102/05-06
20
10
6
-50
20
TA = +25°C
-55
TA = 0°C
12
MAX2105
NOISE FIGURE vs. INPUT CARRIER LEVEL
-50
TA = +25°C
18
10
MAX2102
NOISE FIGURE vs. INPUT CARRIER LEVEL
15
2.2
TA = +70°C
19
14
RFIN CARRIER LEVEL (dBm)
25
2.0
fLO = 2141MHz
15
LO FREQUENCY (MHz)
TA = +70°C
1.8
21
20
TA = +70°C
20
1000 1200 1400 1600 1800 2000 2200
fLO = 1451MHz
1.6
22
15
AGC SET FOR PRFIN = -60dBm
30
1.4
23
14.7
800
1.2
MAX2105
NOISE FIGURE vs. INPUT CARRIER LEVEL
TA = 0°C
14.5
1.0
LO FREQUENCY (GHz)
fLO = 2151MHz
NOISE FIGURE (dB)
NOISE FIGURE (dB)
15.9
14.9
3.6
30
MAX2102/05-03insert
16.3
TA = +25°C
12.0
3.2
MAX2102
NOISE FIGURE vs. INPUT CARRIER LEVEL
MAX2105
NOISE FIGURE vs. FREQUENCY
15.5
2.8
AGC VOLTAGE (V)
AGC VOLTAGE (V)
16.1
TA = 0°C
-60
4
13.0
MAX2102/05-07
3
13.5
NOISE FIGURE (dB)
2
TA = +70°C
14.0
MAX2102/05-05
1
AGC SET FOR
PRFIN = -69dBm
14.5
12.5
-70
-80
MAX2102/05-04
-10
15.0
MAX2102/05-04insert
TA = +70°C
AGC SET FOR
IOUT, QOUT = 0.5Vp-p
NOISE FIGURE (dB)
-20
0
MAX2102/05-02insert
AGC SET FOR IOUT
QOUT = 0.5Vp-p
SINGLE-CARRIER POWER FOR 0.5Vp-p
BASEBAND LEVEL (dBm)
MAX2102/05-03
SINGLE-CARRIER INPUT LEVEL
FOR 0.5Vp-p BASEBAND LEVEL (dBm)
0
-40
MAX2102
NOISE FIGURE vs. FREQUENCY
MAX2105
CARRIER LEVEL vs. AGC VOLTAGE
MAX2102
CARRIER LEVEL vs. AGC VOLTAGE
NOISE FIGURE (dB)
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
0
-50
-55
-60
RFIN CARRIER LEVEL (dBm)
-65
0.8
1.0
1.2
1.4
1.6
1.8
LO FREQUENCY (GHz)
_______________________________________________________________________________________
2.0
2.2
Direct-Conversion Tuner ICs for
Digital DBS Applications
IMAGINARY
-50
-100
-150
TA = 0°C
TA = +25°C
30
TA = +70°C
20
f1 = 2148.1MHz
f2 = 2149MHz
fLO = 2151MHz
AGC SET VIA SERVO LOOP
FOR 0.5V PER TONE
10
-200
0
1.1
1.4
1.7
2.0
2.3
-10
-15
-20
-25
-30
-35
40
IMAGINARY
20
0
-20
-40
0.8
-40
1.1
1.4
1.7
2.0
2.3
FREQUENCY (GHz)
IM3 LEVELS vs. INPUT CARRIERS
POWER LEVEL
RFIN PORT IMPEDANCE
vs. FREQUENCY
LO LEAKAGE AT RFIN vs. FREQUENCY
(SINGLE-ENDED LO DRIVE)
80
60
50
TA = +25°C
40
TA = +70°C
30
f1 = 1448.1MHz
f2 = 1449MHz
fLO = 1451MHz
AGC SET VIA SERVO LOOP
FOR 0.5Vp-p PER TONE
10
20
0
IMAGINARY
-20
-40
MATCHED PER
EV KIT CIRCUIT
-80
-25
-30
-35
1.1
1.4
1.7
2.0
2.3
-80
0.8
1.1
1.4
FREQUENCY (GHz)
-50
-30
fLO = 1075.5MHz
fRFIN = 2150MHz
PRFIN = -69dBm LO DRIVEN
SINGLE ENDED
SPURIOUS SIGNAL LEVEL NORMALIZED
TO LEVEL WHEN FRFIN = 1074.5MHz (dBc)
AGC SET FOR PRFIN = -69dBm
PLO REFERS TO POWER INTO
LO AND LO
2.0
2.3
SPURIOUS DOWNCONVERSION DUE TO
INTERNALLY GENERATED LO 2ND HARMONIC
MAX2102/05-14
-30
1.7
FREQUENCY (GHz)
LO LEAKAGE AT RFIN vs. FREQUENCY
(DIFFERENTIAL LO DRIVE)
LO POWER AT RFIN (dBm)
PLO = -10dBm
-100
0.8
-40
SINGLE INPUT CARRIER LEVEL (dBm)
-40
PLO = -15dBm
-70
-90
-100
-20
-60
-60
0
-15
-50
-31
-32
-60
MAX2102/05-15
20
REAL
40
PLO = -5dBm
-40
LO POWER AT RFIN (dBm)
60
-30
MAX2102/05-12
100
MAX2102/05-11
TA = 0°C
MAX2102/05-13
SINGLE INPUT CARRIER LEVEL (dBm)
70
-10
REAL
60
FREQUENCY (GHz)
SERIES IMPEDANCE (Ω)
0.8
IM3 LEVEL (dBc)
40
MATCHED: MAX2102 TYPICAL
OPERATING CIRCUIT
80
SERIES IMPEDANCE (Ω)
50
0
100
MAX2102/05-09
REAL
IM3 LEVEL (dBc)
SERIES IMPEDANCE (Ω)
50
LO PORT IMPEDANCE vs. FREQUENCY
60
MAX2102/05-08
100
IM3 LEVELS vs. INPUT CARRIER
POWER LEVEL
MAX2102/05-10
LO PORT IMPEDANCE vs. FREQUENCY
(UNMATCHED)
-33
PLO = -5dBm
-70
LO, LO DRIVEN DIFFERENTIAL
(PLO = -15dBm, PLO = -15dBm)
-34
-80
PLO = -10dBm
-90
-35
PLO = -15dBm
-36
-100
0.8
1.1
1.4
1.7
FREQUENCY (GHz)
2.0
2.3
-20
-15
-10
-5
LO POWER (dBm)
_______________________________________________________________________________________
7
MAX2102/MAX2105
Typical Operating Characteristics (continued)
(MAX2102 EV kit circuit (Figure 1), VCC = 5V, PSGND = open, MOD = GND, fRFIN = 2150MHz, PRFIN = -19dBm, fLO = 2150.125MHz,
PLO = -15dBm driven single-ended into LO, AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p, IOUT, QOUT drive AC-coupled
100Ω loads, 2kΩ from PSOUT to GND, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(MAX2102 EV kit circuit (Figure 1), VCC = 5V, PSGND = open, MOD = GND, fRFIN = 2150MHz, PRFIN = -19dBm, fLO = 2150.125MHz,
PLO = -15dBm driven single-ended into LO, AGC set via servo loop for VIOUT = VQOUT = 0.5Vp-p, IOUT, QOUT drive AC-coupled
100Ω loads, 2kΩ from PSOUT to GND, TA = +25°C, unless otherwise noted.)
QUADRATURE GAIN IMBALANCE
vs. FREQUENCY
91
90
TA = +70°C TA = +25°C
89
88
87
0.3
fLO = fRFIN + 125kHz
PRFIN = -40dBm
PLO = -15dBm
0.2
0.1
0
-0.1
TA = +70°C
TA = +25°C
-0.2
2
1
1.25
1.65
2.05
-1
-2
-3
0.85
1.25
1.65
2.05
2.45
0.1
1
10
RFIN FREQUENCY (GHz)
FREQUENCY (MHz)
BASEBAND GROUP DELAY
FLATNESS vs. FREQUENCY
BASEBAND IM LEVELS
BASEBAND OUTPUT IMPEDANCE
vs. FREQUENCY
70
60
2
1
IM LEVELS (dBc)
TA = +25°C
TA = +70°C
0
-1
TA = 0°C
50
40
10
-4
-5
IM3
30
20
-3
IM2
f1 = 1448.1MHz
f2 = 1449MHz
fLO = 1451MHz
PRFIN = -40dBm PER TONE
FREQUENCY (MHz)
100
7
6
5
4
3
2
1
0
0
10
100
MAX2102/05-21
3
8
BASEBAND OUTPUT IMPEDANCE (Ω)
MAX2102/05-19
80
MAX2102/05-20
RFIN FREQUENCY (GHz)
4
1
TA = +70°C
0
-0.4
2.45
5
-2
TA = +25°C
TA = 0°C
TA = 0°C
-0.3
-0.5
0.85
8
0.4
MAX2102/05-18
TA = 0°C
0.5
BASEBAND GAIN (dB)
92
BASEBAND GAIN FLATNESS
vs. FREQUENCY
MAX2102/05-17
fLO = fRFIN + 125kHz
PRFIN = -40dBm
PLO = -15dBm
QOUT LEVEL RELATIVE TO IOUT LEVEL (dB)
93
MAX2102/05-16
QOUT PHASE RELATIVE TO IOUT PHASE (degrees)
QUADRATURE PHASE IMBALANCE
vs. FREQUENCY
BASEBAND GROUP DELAY (ns)
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7
BASEBAND LEVELS, PER TONE (Vp-p)
0.1
1
10
FREQUENCY (MHz)
_______________________________________________________________________________________
100
Direct-Conversion Tuner ICs for
Digital DBS Applications
PIN
NAME
FUNCTION
1
VCC
Baseband +5V Supply. Bypass with a 10pF capacitor from this pin to pin 3 (GND), as close to the IC as
possible. Connect an additional 0.1µF capacitor in parallel with the 10pF capacitor (placement less critical).
2
IOUT
I Channel Baseband Output
3, 12
GND
Baseband Ground
4
VCC
RF +5V Supply. Bypass with a 22pF capacitor from this pin to pin 11 (GND), as close to the IC as possible.
5
GND
Ground (substrate)
6
VCC
RF +5V Supply. Bypass with a 22pF capacitor from this pin to pin 9 (GND), as close to the IC as possible.
7
RFIN
RF Noninverting Input. Couple through a 22pF capacitor directly to a 50Ω signal source.
8
RFIN
RF Inverting Input. Connect to a 22pF series capacitor and a 51Ω resistor to ground.
9, 11,
19, 24
GND
RF Ground. Connect directly to the ground plane.
10
AGC
Automatic Gain-Control Input. Bypass this pin with a 1000pF capacitor close to the pin, to minimize coupling.
13
QOUT
14
VCC
Baseband +5V Supply. Bypass with a 10pF capacitor from this pin to pin 12 (GND), as close to the IC as
possible. Connect an additional 0.1µF capacitor in parallel with the 10pF capacitor (placement less critical).
15
QDC
Q Channel Offset-Correction Noninverting Input. Connect a 0.22µF (typ) capacitor between QDC and QDC.
This capacitor must be placed as close to the IC as possible (see Layout Considerations section).
16
QDC
Q Channel Offset-Correction Inverting Input. Connect a 0.22µF (typ) capacitor between QDC and QDC. This
capacitor must be placed as close to the IC as possible (see Layout Considerations section).
17
IDC
I Channel Offset-Correction Inverting Input. Connect a 0.22µF (typ) capacitor between IDC and IDC. This
capacitor must be placed as close to the IC as possible (see Layout Considerations section).
18
IDC
I Channel Offset-Correction Noninverting Input. Connect a 0.22µF (typ) capacitor between IDC and IDC.
This capacitor must be placed as close to the IC as possible (see Layout Considerations section).
20
VCC
RF +5V Supply. Bypass with a 10pF capacitor from this pin to pin 19 (GND) as close to the IC as possible.
21
LO
Local-Oscillator Complementary Input Port (Figure 1)
22
LO
Local-Oscillator Input Port (Figure 1)
23
VCC
RF +5V Supply. Bypass with a 10pF capacitor from this pin to pin 24 (GND) as close to the IC as possible.
25
PSGND
Prescaler Ground. To disable the prescaler, leave this pin open.
26
PSOUT
Prescaler Output. Drives CMOS load. Connect 2kΩ from this pin to GND (if the prescaler is enabled).
27
MOD
Prescaler Modulus Control. Leave open when the prescaler is disabled.
28
VCC
Prescaler +5V Supply. Must be connected even if the prescaler is disabled. Bypass with a 1000pF
capacitor.
Q Channel Baseband Output
_______________________________________________________________________________________
9
MAX2102/MAX2105
Pin Description
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
VCC
VCC
1
47µF
0.1µF
10pF
2
VCC
VCC
1000pF
IOUT
MOD
100Ω
LOAD
3
0.1µF
4
VCC
5
22pF
28
GND
PSOUT
VCC
PSGND
GND
GND
MODULUS
CONTROL
27
26
PRESCALER
OUTPUT
25
2kΩ
24
10pF
6
VCC
22pF
RF
INPUT
(50Ω
SOURCE)
22pF
7
VCC
MAX2102
MAX2105
VCC
23
VCC
22pF
RFIN
LO
RFIN
LO
GND
VCC
22
LO
INPUT
(50Ω
SOURCE)
22Ω
22pF
8
22pF
9
51Ω
21
20
56Ω
33Ω
10pF
AGC
CONTROL
10
AGC
GND
GND
IDC
GND
IDC
13
QOUT
QDC
14
VCC
QDC
11
1000pF
VCC
19
18
0.22µF
12
47µF
100Ω
LOAD
0.1µF
0.1µF
17
16
10pF
0.22µF
15
VCC
Figure 1. Typical Operating Circuit
Detailed Description
The MAX2102/MAX2105 down-convert signals in the
range 950MHz to 2150MHz directly to baseband I/Q
signals. They are targeted for digital DBS tuner applications where a direct downconversion provides a cost
savings over prior-art, multiple-conversion approaches.
However, the MAX2102/MAX2105 are applicable to any
system requiring a broadband I/Q downconversion.
Internally, the MAX2102 and MAX2105 consist of a
broadband front-end variable gain stage, a quadrature
downconverter, an oscillator buffer, high-linearity I and
Q baseband amplifiers, and offset correction amplifiers.
The MAX2102 features a front-end AGC dynamic range
of over 50dB, while the MAX2105 provides a front-end
10
AGC dynamic range of over 41dB. Specifically, the
AGC control can be adjusted so that a sine wave at
RFIN ranging in power from -69dBm to -19dBm
(MAX2102) or -60dBm to -19dBm (MAX2105) will produce a sine wave at IOUT and QOUT at 500mVp-p levels. The noise figure is lowest when the AGC is at its
maximum gain setting (see Typical Operating
Characteristics). The VSWR at RFIN is unaffected by
the AGC setting.
The local-oscillator (LO) buffer accepts an external LO
signal at LO, LO, and internally limits the signal to provide a consistent on-chip LO level. The LO input drive
level should be maintained within the specified limits
(see Applications Information section).
______________________________________________________________________________________
Direct-Conversion Tuner ICs for
Digital DBS Applications
istic impedance (that is, the equivalent of an AC-coupled, 100Ω load). The baseband -3dB output bandwidth is over 90MHz.
__________Applications Information
Front-End Tuner Circuitry
for DBS Tuners
The resulting I/Q baseband signals are fed through
separate I and Q channel baseband amplifiers. Robust
output stages drive IOUT and QOUT. The outputs are
capable of driving lowpass filters with 100Ω character-
In a typical application, the signal path ahead of the
MAX2102/MAX2105 will include a discrete LNA/buffer
and a PIN-diode attenuator. Alternatively, a dual-gate
LNB
75Ω CABLE
950MHz to 2150MHz
F-CONNECTOR
FOR 2nd SET-TOP BOX
KU BAND
F-CONNECTOR
INPUT
OR
IOUT 0.1µF R
S
AGC
L1
L2
L3
0.1µF
AGC
ADC
RFIN
C1
C2
C3
C4
RFIN
0
90
EXTERNAL
VCO
RL
MAX2102
MAX2105
QOUT
(OPTIONAL
GAIN)
BASEBAND LP FILTERS
LO
0.1µF RS
L1
L2
L3
ADC
C1
LO
OFFSET CORRECTION
C2
C3
C4
RL
OR
TSA5055
OR EQUIV.
DSP:
QPSK
DEMOD
0.1µF
DIV
TANK
MAX1002
MAX1003
IDC IDC QDC QDC PSOUT
MOD
Figure 2. Typical Application
______________________________________________________________________________________
11
MAX2102/MAX2105
The quadrature downconverter follows the front-end
AGC. Two mixers are driven by the previous stage
AGC amplifier output. The mixer LO ports are fed with
the two LO signals, which are 90° apart in phase.
These quadrature LO signals are generated on-chip
using the LO signal from the LO buffer.
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
GaAsFET can serve this function. This circuitry is usually required in order to meet system noise-figure requirements, may provide a buffered F-connector output, and
may also be required to meet stringent LO leakage
requirements. The PIN attenuator is typically controlled
by the same voltage as the MAX2102/MAX2105 AGC
control pin so that, overall, a single AGC line from the
baseband processor can control the entire tuner.
In some applications, a varactor-tuned preselection
bandpass filter is added between the discrete LNA and
the MAX2102/MAX2105. This is usually required only
for very high-linearity tuners, such as those designed
for single channel-per-carrier (low-data-rate) applications. The filter provides a means of broadly filtering
adjacent interferers, thus improving the tuner’s intermodulation performance. Additionally, the filter
removes the RF interference at twice the LO frequency,
which would otherwise add to cochannel interference
(the MAX2102/MAX2105 alone reject this carrier to typically -32.3dBc).
22Ω
22pF
LO
22
56Ω
MAX2102
MAX2105
22Ω
22pF
LO
21
56Ω
LO POWER:
-15dBm TO -5dBm,
POWER INTO LO, LO.
LO, LO DRIVEN DIFFERENTIALLY
External Oscillator
Since the MAX2102/MAX2105 are direct-conversion
receivers, the external LO must tune to the same frequencies as the desired RF input signals.
The MAX2102/MAX2105 oscillator input port (LO, LO)
accepts either a single-ended or differential (balanced)
LO signal. A differential LO offers reduced LO leakage
to the RFIN port, as well as lower spurious downconversion levels of RF signals, which are at twice the LO frequency. Refer to Figure 3 for differential LO
connections. For best performance, ensure that the LO
and LO traces are symmetrical.
The LO drive levels should be maintained to within the
specified limits. If the LO drive falls below the specified
range, quadrature performance may be affected.
Driving LO above the specified limits will cause a higher LO leakage level at RFIN; this may be acceptable in
some applications. The MAX2102/MAX2105 offset-correction loop can withstand LO leakage levels corresponding to at least 0dBm of LO input power drive.
Prescaler
Typical stand-alone tuner applications will not use the
MAX2102/MAX2105 prescaler function, but instead use
a commercial synthesizer IC such as the Philips
TSA5055, which has an internal prescaler. To disable
the MAX2102/MAX2105 prescaler, disconnect the
PSGND pin (leave open). The prescaler will cause an
output spur in the baseband spectrum, to a level of
about -20dBc (referred to 500mVp-p baseband output
level) that may land within the desired signal bandwidth
in some applications.
12
Figure 3. Differential LO Drive
To use the MAX2102/MAX2105 prescaler, connect the
PSGND pin to ground. In some applications, the
prescaler may be toggled on and off using a MOSFET
to switch PSGND to ground. PSGND should be forced
to within 100mV of ground, and the MOSFET must be
capable of sinking 15mA. PSOUT is capable of driving
a typical CMOS load of 10kΩ in parallel with 5pF. A
2kΩ pull-down resistor must be connected from PSOUT
to GND.
The prescaler requires a stable level at the MOD pin
12ns before the falling edge of PREOUT to assert the
desired modulus. The level at MOD must remain static
until 3ns after this falling edge.
Baseband Amplifiers
The MAX2102/MAX2105 baseband amplifiers provide
over 2Vp-p swing at IOUT and QOUT, and are capable
of driving 100Ω. IOUT and QOUT must be AC-coupled
to any lowpass filters. In a typical application, IOUT and
QOUT drive a 5th or 7th-order lowpass filter for ADC
anti-aliasing purposes (see the Systems Considerations:
Lowpass Filters in Direct-Conversion Tuners section).
After the filters, in some cases, additional gain may be
required. This can be accomplished with a pair of videospeed op amps, such as the MAX4216 dual-video op
amp. Alternatively, the MAX1002/MAX1003 dual ADC
has built-in gain ahead of the ADCs, digitizing levels as
low as 125mVp-p. Contact Maxim for more information
about the MAX4216 or the MAX1002/MAX1003.
______________________________________________________________________________________
Direct-Conversion Tuner ICs for
Digital DBS Applications
Layout Considerations
Observe standard RF layout rules. A ground plane is
essential; when connecting areas of ground plane
between layers, use vias liberally. Remove the ground
plane under the external VCO area to reduce parasitic
capacitance. If a ground plane is used under the lowpass filters, note that the filter shape may be slightly offset due to parasitic capacitance.
In a direct-conversion receiver, LO leakage to the RF
input connector is a major issue, since filtering of the
LO is impossible (the LO operates at the same frequency as the RF input). The external VCO section should
be housed in a separate shielded compartment, if possible. Use of a differential (balanced) LO will dramatically reduce LO leakage. Also, the use of coplanar,
waveguide transmission-line structures reduces LO
leakage (used on the MAX2102 EV kit).
Observe the power-supply bypass capacitor connections in the Pin Description table, notably pins 1, 3, 4, 6,
9, 11, 12, 14, 19, 20, 23, and 24. Traces from these IC
pins to the bypass capacitors must be kept to an
absolute minimum. Where possible, make these connections on the top side of the board.
The MAX2102 EV kit includes ferrite beads in series
with power-supply leads. The beads may not be
required for all applications.
Table 1. Suggested Component Values for Discrete Lowpass Filters (0.1dB Ripple
Chebyshev Type)
ADC
SAMPLING
RATE (Msps)
FILTER
TYPE
RS
(Ω)
C1
(pF)
L1
(nH)
C2
(pF)
L2
(nH)
C3
(pF)
L3
(nH)
C4
(pF)
RL
(kΩ)
40
0.1dB Chebyshev,
fC = 20MHz
100
39
910
120
1500
150
1500
120
10
60
0.1dB Chebyshev,
fC = 30MHz
100
22
620
82
910
100
1000
82
10
90
0.1dB Chebyshev,
fC = 45MHz
100
18
390
56
620
68
680
56
10
Note: Suggested types: Inductors: Coilcraft 1008CS, tolerance = ±5%; Capacitors: use tolerance = ±2%. Refer to Figure 2 for circuit
diagram.
______________________________________________________________________________________
13
MAX2102/MAX2105
Offset Correction
The internal offset-correction amplifiers remove the DC
offsets present in the baseband amplifiers. The offsetcorrection loop effectively AC-couples the baseband
signal path, yielding a -3dB highpass corner frequency
according to the following:
f-3dB = 100/CDC (µF)
where C DC is the value of the capacitors, in microfarads, across QDC, QDC and IDC, IDC.
For applications where the DC information must be
maintained through the signal path, the offset correction can be disabled by connecting QDC, QDC, IDC,
and IDC directly to ground. Disabling the offset correction will effectively limit the input dynamic range of the
MAX2102/MAX2105. Typical input dynamic range will
be approximately -45dBm to -19dBm for single-ended
LO drive, and -55dBm to -19dBm for differential LO
drive.
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
Power-Supply Sequencing
The MAX2102/MAX2105 have several +5V supply pins.
The supply layout should be in a star format, with a
bypass capacitor that dominates the rise time of the
supply at the center of the star, to ensure that all pins
see approximately the same voltage during power-up.
The prescaler VCC (pin 28) must be connected to the
same VCC as the other VCC pins, even if the prescaler
is not used. Leaving PSGND open will disable the
prescaler function and, in this state, the prescaler will
not dissipate any power.
Systems Consideration: Lowpass Filters in
Direct-Conversion Tuners
Typically, a 5th or 7th-order L-C lowpass filter is used
for anti-aliasing the ADCs following the MAX2102.
Figures 4 and 5 describe typical filtering requirements.
Table 1 offers suggested component values for these
lowpass filters.
Chip Information
TRANSISTOR COUNT: 1852
SUBSTRATE CONNECTED TO GND
I
ANALOG LP FILTERS
MAX2102
MAX2105
ADCs
MATCHED FILTERS
Q
DIGITAL SIGNAL PROCESSING
“1”
“2”
“3”
“4”
Figure 4. I, Q Signal Path
14
______________________________________________________________________________________
Direct-Conversion Tuner ICs for
Digital DBS Applications
MAX2102/MAX2105
TRANSPONDER BW = 24MHz
0
AT SIGNAL
POINT NO. 1
DESIRED
CHANNEL
(20Msps)
dBc
UNDESIRED ADJACENT CHANNEL
-30
0
10 12
17.16
20
29.16
40 41.16
MHz
α = 0.2
DATA NYQUIST
ADC SAMPLING
NYQUIST FOR ADC
TRANSPONDER SPACING = 29.16 MHz
LOWPASS FILTER RESPONSE
0
AT SIGNAL
POINT NO. 2
DESIRED
CHANNEL
(20Msps)
dBc
-30
0
10 12
17.16
20
28
FILTER CUTOFF
40
MHz
ADC SAMPLING
PASSBAND FILTER REQUIREMENTS:
(1) <20% OF BAUD PERIOD DELAY RIPPLE
(2) <0.1dB GAIN RIPPLE
TRANSITION BAND FILTER REQUIREMENTS:
< 2dB GAIN RIPPLE
0
AT SIGNAL
POINT NO.3
DESIRED
CHANNEL
(20Msps)
dBc
ADJ
CHANNEL
FOLDOVER
-30
0
10 12
17.16
20
40
ADC NYQUIST
MHz
ADC SAMPLING
DIGITAL MATCHED FILTER
AT SIGNAL
POINT NO.4
DESIRED
CHANNEL
(20Msps)
dBc
-30
0
10 12
40
MHz
ADC SAMPLING
Figure 5. Lowpass Filtering Example. Note: Data Rate = 40Mbps, Transponder BW = 24MHz, Transponder Spacing = 29.16MHz,
Nyquist Filter: α = 0.2
______________________________________________________________________________________
15
________________________________________________________Package Information
SOICW.EPS
MAX2102/MAX2105
Direct-Conversion Tuner ICs for
Digital DBS Applications
16
______________________________________________________________________________________