Rainbow Electronics MAX2105 User Manual

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.

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).

________________________Applications

DBS Tuners Wireless Local Loop
DVB-Compliant DBS Tuners Broadband Systems
Cellular Base Stations LMDS

____________________________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

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

________________________________________________________________

Maxim Integrated Products

1

MAX2102
MAX2105

Q

I

V

CC

QOUT GND GND AGC GND RFIN V

CC

GND V

CC

GND IOUT V

CC

OFFSET CORRECTION

/64, /65

90°

0°

RFIN

QDC

IDC IDC GND V

CC

LO V

CC

GND PSGND PSOUT MOD V

CC

LOQDC

14

1312111098 7654321

15 16 17 18 19 20 21 22

23

24 25 26 27 28

Functional Diagram

19-1256; Rev 2; 10/98

PART

MAX2102CWI

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

28 SO

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

Ordering Information

†

Patents pending

*

Contact factory for MAX2102/MAX2105 versions with expanded frequency range.

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].

MAX2105CWI

0°C to +70°C 28 SO

AGC Input Bias Current

MAX2102/MAX2105

Direct-Conversion Tuner ICs for
Digital DBS Applications

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +4.75V to +5.25V; GND = 0V; PSGND = GND; AGC = 1.3V; MOD = 0.8V; P

RFIN

= OFF, fLO= 1450.125MHz; PLO= -15dBm;

IOUT, QOUT = open; T

A

= 0°C to +70°C; unless otherwise noted.)

AC ELECTRICAL CHARACTERISTICS

(MAX2102 EV kit circuit (Figure 1); VCC= +5V; PSGND = open; MOD = GND; f

RFIN

= 2150MHz; P

RFIN

= -19dBm; fLO=

2150.125MHz; P

LO

= -15dBm driven single-ended into LO; AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p; IOUT, QOUT drive

AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; T

A

= +25°C; unless otherwise noted.)

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.

VCCto GND..............................................................-0.5V to +7V

RFIN to

RFIN ..........................................................................±2V

LO to LO ................................................................................±2V

AGC, MOD, RFIN, RFIN, LO, LO to GND.....-0.5V to (V

CC

+ 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 (V

CC

+ 0.5V)

Continuous Power Dissipation (T

A

= +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

MAX2102

0V ≤ V

MOD

≤ V

CC

CONDITIONS

mA150 195Quiescent Supply Current

V4.75 5.25Operating Supply Voltage Range

V2.2 2.6IOUT, QOUT Common-Mode Voltage

-250 180

V0.8MOD Input Low Level
V2.0MOD Input High Level

µA-80 10MOD Input Bias Current

UNITSMIN TYP MAXPARAMETER

Refers to single-carrier power generating
V

IOUT

= V

QOUT

= 0.5Vp-p,

950MHz < f

RFIN

< 2150MHz,

950MHz < fLO< 2150MHz (Note 2)

(Note 1)

Refers to single-carrier power generating
V

IOUT

= V

QOUT

= 0.5Vp-p,

950MHz < f

RFIN

< 2150MHz,

950MHz < fLO< 2150MHz (Note 2)

CONDITIONS

dBm

RFIN Maximum Single-Carrier
Input Power

MHz950 2150RFIN Carrier Frequency Range

dBm

-69

RFIN Minimum Single-Carrier
Input Power

50

UNITSMIN TYP MAXPARAMETER

-19

MAX2102

MAX2105 -60

0.5V ≤ V

AGC

≤ 4V

dB

41

AGC Range

MAX2102
MAX2105

RF FRONT END

MAX2105

µA

-180 180

AGC Input Bias Current

SUPPLY

CONTROL INPUTS, PRESCALER

0.5V ≤ V

AGC

≤ 4V

1V ≤ V

AGC

≤ 4V

1V ≤ V

AGC

≤ 4V

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS

(MAX2102 EV kit circuit (Figure 1); VCC= +5V; PSGND = open; MOD = GND; f

RFIN

= 2150MHz; P

RFIN

= -19dBm; fLO=

2150.125MHz; P

LO

= -15dBm driven single-ended into LO; AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p; IOUT, QOUT drive

AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; T

A

= +25°C; unless otherwise noted.)

P

RFIN

= -19dBm per tone, AGC set via servo loop for

V

IOUT

= V

QOUT

= 0.5Vp-p per tone,

f1

RFIN

= 1448.1MHz, f2

RFIN

= 1449MHz,

f

LO

= 1451MHz

P

RFIN

= -19dBm per tone, AGC set via servo loop for

V

IOUT

= V

QOUT

= 0.5Vp-p per tone,

f1

RFIN

= 1200MHz, f2

RFIN

= 2150MHz,

f

LO

= 951MHz

f

RFIN

= 1441MHz,

f

LO

= 1451MHz

CONDITIONS

dBm6.5RFIN Input Third-Order Intercept

11.2

dBm15.1RFIN Input Second-Order Intercept

13.2

12.9

UNITSMIN TYP MAXPARAMETER

f

RFIN

= 950MHz to 2150MHz, 50Ω source

Defined as ∆NF/∆Gain; for AGC range,
defined as single-carrier power range
of -69dBm to -59dBm (MAX2102) or

-60dBm to -50dBm (MAX2105)

950MHz < f

RFIN

< 2150MHz, 950MHz < fLO<
2150MHz. Dominated by LO second-harmonic power
causing downconversion of unwanted channel. Test
conditions: f

LO

= 1075.5MHz, f

RFIN

= 2150MHz,

P

RFIN

= -69dBm (MAX2102) or -60dBm (MAX2105)
PLO= -15dBm, 950MHz < fLO< 2150MHz (Note 3)
PLO= -15dBm, PLO= -15dBm (differentially driven),

950MHz < f

LO

< 2150MHz (Note 3)

2.3:1

dB/dB

-0.5

Maximum Noise-Figure Variation with
AGC Gain Setting

RFIN Worst-Case VSWR across
Band

dBc-32.3

Maximum Power of Spurious
Downconversion Products

dBm

-49

-54

LO Leakage at RFIN

P

RFIN

= -69dBm

AGC = 4V,
P

RFIN

set via servo

loop for V

IOUT

=

V

QOUT

= 0.5Vp-p

MAX2102

MAX2102

dB

P

RFIN

= -60dBm MAX2105 15.7

P

RFIN

= -69dBm

f

RFIN

= 2141MHz,

f

LO

= 2151MHz

Noise Figure

MAX2105P

RFIN

= -60dBm 15.5

MAX2102

MAX2105 11.5

MAX2102

MAX2105 -0.7

MAX2102/MAX2105

Direct-Conversion Tuner ICs for
Digital DBS Applications

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2102 EV kit circuit (Figure 1); VCC= +5V; PSGND = open; MOD = GND; f

RFIN

= 2150MHz; P

RFIN

= -19dBm; fLO=

2150.125MHz; P

LO

= -15dBm driven single-ended into LO; AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p; IOUT, QOUT drive

AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; T

A

= +25°C; unless otherwise noted.)

2kΩ || 10pF load

TA= 0°C to +70°C
(Note 2)

(Note 1)

At -3dB attenuation

P

RFIN

= -50dBm; AGC = 4V, VCC= 5.0V

PSOUT load = 2kΩ || 5pF (Note 3)

Vp-p0.8Prescaler Output Swing at PSOUT

950MHz < f

RFIN

< 2150MHz;

950MHz < f

LO

< 2150MHz; P

RFIN

= -40dBm;

f

IOUT

, f

QOUT

= 125kHz (Note 2)

950MHz < f

RFIN

< 2150MHz;

950MHz < f

LO

< 2150MHz; P

RFIN

= -40dBm;

f

IOUT

, f

QOUT

= 125kHz (Note 2)

fLO= 950MHz to 2150MHz, 50Ω source into
MAX2102 EV kit match circuit

(Note 4)
Refers to power level driven into LO,

LO (differentially driven) (Notes 2, 4)

65 65

(Notes 2, 5)

CONDITIONS

64 64

Prescaler Divide Ratio

MHz94

Baseband Bandwidth
(at IOUT, QOUT)

Vp-p2.7IOUT, QOUT Clipping Level

%35 65Prescaler Duty Cycle at PSOUT

1kHz < (f

IOUT, fQOUT

) < 25MHz, 950MHz < f

RFIN

<

2150MHz, 950MHz < f

LO

< 2150MHz (Notes 3, 7, 8)

1kHz < (f

IOUT, fQOUT

) < 25MHz, 950MHz < f

RFIN

<

2150MHz, 950MHz < f

LO

< 2150MHz (Notes 3, 7, 8)

ns0.45

dB0.45 0.85

Baseband Gain Ripple
(at IOUT, QOUT)

Baseband Group Delay Ripple
(at IOUT, QOUT)

MHz950 2150LO Input Frequency Range

dB0.5IOUT, QOUT Amplitude Imbalance

degrees3IOUT, QOUT Phase Imbalance

1.75:1

LO Input Worst-Case VSWR over
Band

-15 -5

LO Input Power Level dBm

-15
dB28RFIN to LO Input Isolation

UNITSMIN TYP MAXPARAMETER

MOD = low
MOD = high

TA= +25°C to +70°C (Notes 2 and 6)

degrees

-0.1 0.6

Worst-Case Additional Phase
Imbalance Over Temperature

TA= +25°C to +0°C (Note 2) -0.07 1

OSCILLATOR BUFFER, QUADRATURE GENERATOR, PRESCALER

BASEBAND AC CHARACTERISTICS

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

_______________________________________________________________________________________ 5

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2102 EV kit circuit (Figure 1); VCC= +5V; PSGND = open; MOD = GND; f

RFIN

= 2150MHz; P

RFIN

= -19dBm; fLO=

2150.125MHz; P

LO

= -15dBm driven single-ended into LO; AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p; IOUT, QOUT drive

AC-coupled 100Ω loads; 2kΩ from PSOUT to GND; T

A

= +25°C; unless otherwise noted.)

(Note 3)
(Note 3)

VCC= 5V + 50mVp-p at 300kHz. Amplitude of
300kHz relative to 500mVp-p measured at IOUT,
QOUT. Measured using MAX2102 EV kit.

CONDITIONS

Ω4.7 10IOUT, QOUT Output Impedance
Ω±1

Maximum IOUT to QOUT Output
Impedance Difference

dB32

Power-Supply Ripple Rejection
(measured at IOUT, QOUT)

UNITSMIN TYP MAXPARAMETER

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: P

RFIN

= -20dBm, and 2) Overdrive test: P

RFIN

= -5dBm but AGC set via servo

loop for V

IOUT

= V

QOUT

= 0.5Vp-p for P

RFIN

= -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 f

RFIN

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, f

RFIN

= 2150MHz, P

RFIN

= -19dBm, fLO= 2150.125MHz,

PLO= -15dBm driven single-ended into LO, AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p, IOUT, QOUT drive AC-coupled

100Ω loads, 2kΩ from PSOUT to GND, TA= +25°C, unless otherwise noted.)

120

130

140

150

160

170

180

4.75 4.85 5.00 5.15 5.25

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX2102/05-01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

TA = 0°C

TA = +70°C

PSGND = GND
(PRESCALER ENABLED)

TA = +25°C

-80

-60

-70

-40

-50

-30

-20

-10

0

0.8 1.2 1.41.0 1.6 1.8 2.0 2.2

MAX2102

AGC RANGE vs. FREQUENCY

MAX2102/05-02

RFIN FREQUENCY (GHz)

SINGLE-CARRIER POWER FOR 0.5Vp-p

BASEBAND LEVEL (dBm)

TA = +70°C

TA = +25°C

TA = 0°C

TA = +70°C

TA = +25°C

TA = 0°C

AGC = 4V

AGC RANGE

AGC = 1V

-80

-50

-60

-70

-40

-30

-10

-20

0

0.8 1.0 1.2 1.4 1.6

1.8

2.0 2.2

MAX2105

AGC RANGE vs. FREQUENCY

MAX2102/05-01insert

RFIN FREQUENCY (GHz)

SINGLE CARRIER POWER FOR 0.5Vp-p

BASEBAND LEVEL (dBm)

TA = 0°C

AGC = 1V

AGC = 4V

TA = 0°C

TA = +25°C

TA = +70°C

TA = +70°C

TA = +25°C

MAX2102/MAX2105

Direct-Conversion Tuner ICs for
Digital DBS Applications

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(MAX2102 EV kit circuit (Figure 1), VCC= 5V, PSGND = open, MOD = GND, f

RFIN

= 2150MHz, P

RFIN

= -19dBm, fLO= 2150.125MHz,

PLO= -15dBm driven single-ended into LO, AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p, IOUT, QOUT drive AC-coupled

100Ω loads, 2kΩ from PSOUT to GND, TA= +25°C, unless otherwise noted.)

0

3

4

1

2

6
5

7

8

9

10

0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2

INPUT-REFERRED IP3 vs. FREQUENCY

MAX2102/05-07

LO FREQUENCY (GHz)

INPUT IP3 (dBm)

TA = +70°C

TA = 0°C

TA = +25°C

f1 = f

LO

- 2MHz

f2 = f

LO

- 2.9MHz

P

RFIN

= -19dBm PER TONE
AGC SET VIA SERVO LOOP
FOR 0.5Vp-p PER TONE

10

15

20

25

30

-50 -60-55 -65 -70 -75

MAX2102

NOISE FIGURE vs. INPUT CARRIER LEVEL

MAX2102/05-05

RFIN CARRIER LEVEL (dBm)

NOISE FIGURE (dB)

TA = +70°C

TA = +25°C

TA = 0°C

fLO = 2151MHz

10

15

20

25

30

-50 -60-55 -65 -70 -75

MAX2102

NOISE FIGURE vs. INPUT CARRIER LEVEL

MAX2102/05-06

RFIN CARRIER LEVEL (dBm)

NOISE FIGURE (dB)

TA = +70°C

TA = +25°C

TA = 0°C

fLO = 1451MHz

12.0

13.0

12.5

13.5

14.0

14.5

15.0

0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2

MAX2102

NOISE FIGURE vs. FREQUENCY

MAX2102/05-04

LO FREQUENCY (GHz)

NOISE FIGURE (dB)

TA = 0°C

TA = +25°C

TA = +70°C

AGC SET FOR
P

RFIN

= -69dBm

0

-80
1 2 3 4

MAX2102

CARRIER LEVEL vs. AGC VOLTAGE

-60

-40

-20

MAX2102/05-03

AGC VOLTAGE (V)

SINGLE-CARRIER INPUT LEVEL

FOR 0.5Vp-p BASEBAND LEVEL (dBm)

AGC SET FOR I

OUT

Q

OUT

= 0.5Vp-p

TA = +70°C

TA = +25°C

TA = 0°C

-70

-40

-50

-60

-30

-10

-20

0

1.6 2.0 2.4

2.8 3.2

3.6

4.0

MAX2105

CARRIER LEVEL vs. AGC VOLTAGE

MAX2102/05-02insert

AGC VOLTAGE (V)

SINGLE-CARRIER POWER FOR 0.5Vp-p

BASEBAND LEVEL (dBm)

TA = 0°C

TA = +25°C

TA = +70°C

AGC SET FOR
I

OUT

, Q

OUT

= 0.5Vp-p

14.5

15.5

15.3

15.1

14.9

14.7

15.7

16.1

15.9

16.3

800

1000

1200 1400 1600 1800 2000

2200

MAX2105

NOISE FIGURE vs. FREQUENCY

MAX2102/05-03insert

LO FREQUENCY (MHz)

NOISE FIGURE (dB)

0°C NF (dB)

AGC SET FOR P

RFIN

= -60dBm

+25°C NF (dB)

+70°C NF (dB)

12

19
18

16
15
14

17

13

20

22
21

23

-50 -55 -60

-65

MAX2105

NOISE FIGURE vs. INPUT CARRIER LEVEL

MAX2102/05-04insert

RFIN CARRIER LEVEL (dBm)

NOISE FIGURE (dB)

TA = 0°C

TA = +70°C

fLO = 2141MHz

TA = +25°C

12

19
18

16
15
14

17

13

20

22
21

23

-50 -55 -60

-65

MAX2105

NOISE FIGURE vs. INPUT CARRIER LEVEL

MAX2102/05-05insert

RFIN CARRIER LEVEL (dBm)

NOISE FIGURE (dB)

TA = 0°C

TA = +70°C

TA = +25°C

fLO = 1441MHz

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

_______________________________________________________________________________________

7

-200

-150

-100

-50

0

50

100

0.8 1.1 1.4 1.7 2.0 2.3

LO PORT IMPEDANCE vs. FREQUENCY

(UNMATCHED)

MAX2102/05-08

FREQUENCY (GHz)

SERIES IMPEDANCE (Ω)

REAL

IMAGINARY

0

20

10

40

30

50

60

-10 -20 -25-15 -30 -35 -40

IM3 LEVELS vs. INPUT CARRIER

POWER LEVEL

MAX2102/05-09

SINGLE INPUT CARRIER LEVEL (dBm)

IM3 LEVEL (dBc)

TA = +70°C

TA = +25°C

TA = 0°C

f1 = 2148.1MHz
f2 = 2149MHz
f

LO

= 2151MHz
AGC SET VIA SERVO LOOP
FOR 0.5V PER TONE

0

20

10

40

50

30

60

70

-10 -20 -25-15 -30 -35 -40

IM3 LEVELS vs. INPUT CARRIERS

POWER LEVEL

MAX2102/05-11

SINGLE INPUT CARRIER LEVEL (dBm)

IM3 LEVEL (dBc)

TA = +70°C

TA = +25°C

TA = 0°C

f1 = 1448.1MHz
f2 = 1449MHz
f

LO

= 1451MHz
AGC SET VIA SERVO LOOP
FOR 0.5Vp-p PER TONE

Typical Operating Characteristics (continued)

(MAX2102 EV kit circuit (Figure 1), VCC= 5V, PSGND = open, MOD = GND, f

RFIN

= 2150MHz, P

RFIN

= -19dBm, fLO= 2150.125MHz,

PLO= -15dBm driven single-ended into LO, AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p, IOUT, QOUT drive AC-coupled

100Ω loads, 2kΩ from PSOUT to GND, TA= +25°C, unless otherwise noted.)

-40

0

-20

40

20

80

60

REAL

100

0.8 1.1 1.4 1.7 2.0 2.3

LO PORT IMPEDANCE vs. FREQUENCY

MAX2102/05-10

FREQUENCY (GHz)

SERIES IMPEDANCE (Ω)

MATCHED: MAX2102 TYPICAL
OPERATING CIRCUIT

IMAGINARY

-100

-60

-80

-20

-40

20

0

40

80
60

100

0.8 1.1 1.4 1.7 2.0 2.3

RFIN PORT IMPEDANCE

vs. FREQUENCY

MAX2102/05-12

FREQUENCY (GHz)

SERIES IMPEDANCE (Ω)

REAL

IMAGINARY

MATCHED PER
EV KIT CIRCUIT

-100

-80

-90

-60

-70

-40

-50

-30

0.8 1.41.1 1.7 2.0 2.3

LO LEAKAGE AT RFIN vs. FREQUENCY

(SINGLE-ENDED LO DRIVE)

MAX2102/05-13

FREQUENCY (GHz)

LO POWER AT RFIN (dBm)

PLO = -15dBm

PLO = -5dBm

PLO = -10dBm

-100

-80

-90

-60

-70

-40

-50

-30

0.8 1.41.1 1.7 2.0 2.3

LO LEAKAGE AT RFIN vs. FREQUENCY

(DIFFERENTIAL LO DRIVE)

MAX2102/05-14

FREQUENCY (GHz)

LO POWER AT RFIN (dBm)

AGC SET FOR P

RFIN

= -69dBm

P

LO

REFERS TO POWER INTO

LO AND LO

PLO = -15dBm

PLO = -5dBm

PLO = -10dBm

-36

-34

-35

-32

-33

-31

-30

-20 -15 -10 -5

SPURIOUS DOWNCONVERSION DUE TO

INTERNALLY GENERATED LO 2ND HARMONIC

MAX2102/05-15

LO POWER (dBm)

SPURIOUS SIGNAL LEVEL NORMALIZED

TO LEVEL WHEN F

RFIN

= 1074.5MHz (dBc)

fLO = 1075.5MHz
f

RFIN

= 2150MHz

P

RFIN

= -69dBm

LO DRIVEN
SINGLE ENDED

LO, LO DRIVEN DIFFERENTIAL
(P

LO

= -15dBm, PLO = -15dBm)

MAX2102/MAX2105

Direct-Conversion Tuner ICs for
Digital DBS Applications

8 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(MAX2102 EV kit circuit (Figure 1), VCC= 5V, PSGND = open, MOD = GND, f

RFIN

= 2150MHz, P

RFIN

= -19dBm, fLO= 2150.125MHz,

PLO= -15dBm driven single-ended into LO, AGC set via servo loop for V

IOUT

= V

QOUT

= 0.5Vp-p, IOUT, QOUT drive AC-coupled

100Ω loads, 2kΩ from PSOUT to GND, TA= +25°C, unless otherwise noted.)

0

20
10

30

60

70

50
40

80

0.7 0.9 1.0 1.1 1.20.8 1.3 1.4 1.5 1.6 1.7

BASEBAND IM LEVELS

MAX2102/05-20

BASEBAND LEVELS, PER TONE (Vp-p)

IM LEVELS (dBc)

IM2

IM3

f1 = 1448.1MHz
f2 = 1449MHz
f

LO

= 1451MHz

P

RFIN

= -40dBm PER TONE

87

88

89

90

91

92

93

0.85 1.25 1.65 2.05 2.45

QUADRATURE PHASE IMBALANCE

vs. FREQUENCY

MAX2102/05-16

RFIN FREQUENCY (GHz)

QOUT PHASE RELATIVE TO IOUT PHASE (degrees)

fLO = f

RFIN

+ 125kHz

P

RFIN

= -40dBm

P

LO

= -15dBm

TA = +70°C

TA = 0°C

T

A

= +25°C

-0.5

-0.3

-0.4

-0.2

0

-0.1

0.2

0.1

0.3

0.4

0.5

0.85 1.25 1.65 2.05

2.45

QUADRATURE GAIN IMBALANCE

vs. FREQUENCY

MAX2102/05-17

RFIN FREQUENCY (GHz)

QOUT LEVEL RELATIVE TO IOUT LEVEL (dB)

TA = +70°C

fLO = f

RFIN

+ 125kHz

P

RFIN

= -40dBm

P

LO

= -15dBm

TA = +25°C

TA = 0°C

5

-5
1 10 100

BASEBAND GROUP DELAY

FLATNESS vs. FREQUENCY

-3

-4

MAX2102/05-19

FREQUENCY (MHz)

BASEBAND GROUP DELAY (ns)

-1

-2

1

2

0

3

4

TA = +70°C

TA = +25°C

TA = 0°C

2

-3

0.1 10 100

BASEBAND GAIN FLATNESS

vs. FREQUENCY

-2

1

0

-1

MAX2102/05-18

FREQUENCY (MHz)

BASEBAND GAIN (dB)

1

TA = +70°C

TA = +25°C

TA = 0°C

8
7

0

0.1 1 10 100

BASEBAND OUTPUT IMPEDANCE

vs. FREQUENCY

3
2
1

5
4

6

MAX2102/05-21

FREQUENCY (MHz)

BASEBAND OUTPUT IMPEDANCE (Ω)

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

_______________________________________________________________________________________ 9

Pin Description

RF Ground. Connect directly to the ground plane.GND

9, 11,

19, 24

Automatic Gain-Control Input. Bypass this pin with a 1000pF capacitor close to the pin, to minimize cou­pling.

AGC10

Q Channel Baseband OutputQOUT13
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).

V

CC

14

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).

QDC15

Ground (substrate)GND5
RF +5V Supply. Bypass with a 22pF capacitor from this pin to pin 9 (GND), as close to the IC as possible.V

CC

6

RF Noninverting Input. Couple through a 22pF capacitor directly to a 50Ω signal source.RFIN7
RF Inverting Input. Connect to a 22pF series capacitor and a 51Ω resistor to ground.

RFIN

8

RF +5V Supply. Bypass with a 22pF capacitor from this pin to pin 11 (GND), as close to the IC as possible.V

CC

4

Baseband GroundGND3, 12

PIN

I Channel Baseband OutputIOUT2

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).

V

CC

1

FUNCTIONNAME

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).

QDC

16

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).

IDC

17

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).

IDC18

RF +5V Supply. Bypass with a 10pF capacitor from this pin to pin 19 (GND) as close to the IC as possible.V

CC

20

Local-Oscillator Complementary Input Port (Figure 1)

LO

21

Local-Oscillator Input Port (Figure 1)LO22
RF +5V Supply. Bypass with a 10pF capacitor from this pin to pin 24 (GND) as close to the IC as possible.V

CC

23

Prescaler Ground. To disable the prescaler, leave this pin open.PSGND25
Prescaler Output. Drives CMOS load. Connect 2kΩ from this pin to GND (if the prescaler is enabled).PSOUT26
Prescaler Modulus Control. Leave open when the prescaler is disabled.MOD27
Prescaler +5V Supply. Must be connected even if the prescaler is disabled. Bypass with a 1000pF

capacitor.

V

CC

28

MAX2102/MAX2105

Direct-Conversion Tuner ICs for
Digital DBS Applications

10 ______________________________________________________________________________________

V

CC

28

27

26
25

24

23

22

21

20

56Ω

33Ω

19

18

17

16

15

0.22µF

0.22µF

22pF

22pF

10pF

1000pF

22Ω

10pF

2

1

3

4

5

6

7

8

9

10

11

12

13

14

IOUT

GND

RFIN

RFIN

GND

GND

V

CC

V

CC

V

CC

V

CC

AGC

CONTROL

V

CC

100Ω
LOAD

AGC

GND

GND

QOUT

V

CC

V

CC

V

CC

V

CC

PRESCALER
OUTPUT

LO
INPUT
(50Ω
SOURCE)

MODULUS
CONTROL

V

CC

MOD

PSOUT

LO

LO

GND

V

CC

PSGND

V

CC

GND

IDC

IDC

QDC

QDC

10pF

1000pF

V

CC

22pF

22pF

22pF

22pF

51Ω

0.1µF

0.1µF

10pF

47µF

0.1µF

47µF

RF

INPUT

(50Ω

SOURCE)

MAX2102
MAX2105

2kΩ

100Ω
LOAD

0.1µF

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

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).

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

______________________________________________________________________________________ 11

R

S

BASEBAND LP FILTERS

(OPTIONAL

GAIN)

DSP:

QPSK

DEMOD

0.1µF0.1µF

R

L

L1

L2 L3

OR

C1

C2 C3 C4

0

90

ADC

ADC

AGC

MAX1002
MAX1003

R

S

IDC QDCIDC

LO

AGC

IOUT

QOUT

DIV

RFIN

RFIN

EXTERNAL

VCO

LO

OFFSET CORRECTION

OR

QDC PSOUT

TANK

TSA5055

OR EQUIV.

MOD

0.1µF0.1µF

R

L

L1

L2 L3

C1

C2 C3 C4

KU BAND

75Ω CABLE

950MHz to 2150MHz

F-CONNECTOR

INPUT

F-CONNECTOR

FOR 2nd SET-TOP BOX

LNB

MAX2102
MAX2105

Figure 2. Typical Application

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.

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-

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

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

MAX2102/MAX2105

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).

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.

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

12 ______________________________________________________________________________________

MAX2102
MAX2105

22Ω

56Ω

22pF

LO

22

21

22Ω

56Ω

22pF

LO POWER:

-15dBm TO -5dBm,
POWER INTO LO, LO.
LO, LO DRIVEN DIFFERENTIALLY

LO

Figure 3. Differential LO Drive

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 CDCis 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 correc-
tion 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.

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.

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

______________________________________________________________________________________ 13

Table 1. Suggested Component Values for Discrete Lowpass Filters (0.1dB Ripple
Chebyshev Type)

Note: Suggested types: Inductors: Coilcraft 1008CS, tolerance = ±5%; Capacitors: use tolerance = ±2%. Refer to Figure 2 for circuit

diagram.

0.1dB Chebyshev,
f

C

= 20MHz

40

0.1dB Chebyshev,
f

C

= 30MHz

60

0.1dB Chebyshev,
f

C

= 45MHz

90

ADC

SAMPLING

RATE (Msps)

FILTER

TYPE

100

100

100

R

S

(Ω)

39

22

18

C1

(pF)

910

620

390

L1

(nH)

120

82

56

C2

(pF)

1500

910

620

L2

(nH)

150

100

68

C3

(pF)

1500

1000

680

L3

(nH)

120

82

56

C4

(pF)

10

10

10

R

L

(kΩ)

MAX2102/MAX2105

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 VCCas the other VCCpins, 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

Direct-Conversion Tuner ICs for
Digital DBS Applications

14 ______________________________________________________________________________________

Q

I

“1” “2” “3” “4”

MATCHED FILTERS

DIGITAL SIGNAL PROCESSING

ANALOG LP FILTERS ADCs

MAX2102
MAX2105

Figure 4. I, Q Signal Path

MAX2102/MAX2105

Direct-Conversion Tuner ICs for

Digital DBS Applications

______________________________________________________________________________________ 15

MHz

DESIRED

CHANNEL

(20Msps)

dBc

AT SIGNAL
POINT NO. 2

0

0 10

PASSBAND FILTER REQUIREMENTS:
(1) <20% OF BAUD PERIOD DELAY RIPPLE
(2) <0.1dB GAIN RIPPLE

TRANSITION BAND FILTER REQUIREMENTS:
< 2dB GAIN RIPPLE

FILTER CUTOFF

12 20 28 40 MHz17.16

-30

ADC SAMPLING

TRANSPONDER SPACING = 29.16 MHz

LOWPASS FILTER RESPONSE

DESIRED

CHANNEL

(20Msps)

UNDESIRED ADJACENT CHANNEL

TRANSPONDER BW = 24MHz

dBc

AT SIGNAL
POINT NO. 1

0

0 10

DATA NYQUIST

NYQUIST FOR ADC

α = 0.2

12 20 29.16 40 41.1617.16

-30

ADC SAMPLING

MHz

DESIRED

CHANNEL

(20Msps)

ADJ

CHANNEL

FOLDOVER

dBc

AT SIGNAL
POINT NO.3

0

0 10

ADC NYQUIST

12 20 4017.16

-30

ADC SAMPLING

MHz

DESIRED

CHANNEL

(20Msps)

DIGITAL MATCHED FILTER

dBc

AT SIGNAL
POINT NO.4

0 10 12 40

-30

ADC SAMPLING

Figure 5. Lowpass Filtering Example.

Note:

Data Rate = 40Mbps, Transponder BW = 24MHz, Transponder Spacing = 29.16MHz,

Nyquist Filter:

α

= 0.2

MAX2102/MAX2105

Direct-Conversion Tuner ICs for
Digital DBS Applications

16 ______________________________________________________________________________________

________________________________________________________Package Information

SOICW.EPS