MAXIM MAX2112 Technical data

General Description

The MAX2112 low-cost, direct-conversion tuner IC is
designed for satellite set-top and VSAT applications.
The IC is intended for 8PSK and Digital Video
Broadcast (DVB-S2) applications.

The MAX2112 directly converts the satellite signals
from the LNB to baseband using a broadband I/Q
downconverter. The operating frequency range extends
from 925MHz to 2175MHz.

The device includes an LNA and an RF variable-gain
amplifier, I and Q downconverting mixers, and baseband
lowpass filters with programmable cutoff frequency control
and digitally controlled baseband variable-gain amplifiers.
Together, the RF and baseband variable-gain amplifiers
provide more than 80dB of gain control range. The IC is
compatible with virtually all DVB-S2 demodulators.

The MAX2112 includes fully monolithic VCOs, as well as
a complete fractional-N frequency synthesizer.
Additionally, an on-chip crystal oscillator is provided
along with a buffered output for driving additional tuners
and demodulators. Synthesizer programming and device
configuration are accomplished with a 2-wire serial inter­face. The IC features a VCO autoselect (VAS) function
that automatically selects the proper VCO. For multituner
applications, the device can be configured to have one
of two 2-wire interface addresses. A low-power standby
mode is available whereupon the signal path is shut
down while leaving the reference oscillator, digital inter­face, and buffer circuits active, providing a method to
reduce power in single and multituner applications.

The MAX2112 is the most advanced DBS tuner avail­able today. The low noise figure eliminates the need for
an external LNA. A small number of passive compo­nents are needed to form a complete DVB-S2 RF front­end solution. The tuner is available in a very small
28-pin thin QFN package.

Applications

DirecTV and Dish Network DBS

DVB-S2

VSATs

Features

o 925MHz to 2175MHz Frequency Range
o Monolithic VCO

Low Phase Noise: -97dBc/Hz at 10kHz
No Calibration Required

o High Dynamic Range: -75dBm to 0dBm
o Integrated Variable BW LP Filters: 4MHz to 40MHz
o Single +3.3V ±5% Supply
o Low-Power Standby Mode
o Address Pin for Multituner Applications
o Differential I/Q Interface
o I2C 2-Wire Serial Interface
o Very Small 28-Pin TQFN Package

MAX2112

Complete, Direct-Conversion

Tuner for DVB-S2 Applications

________________________________________________________________

Maxim Integrated Products

1

Pin Configuration/

Functional Diagram

Ordering Information

19-0869; Rev 2; 5/10

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

*

EP = Exposed paddle.

+

Denotes a lead(Pb)-free/RoHS-compliant package.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX2112CTI+ 0°C to +70°C

28 Thin QFN-EP*

MAX2112ETI+ -40°C to +85°C

28 Thin QFN-EP*

VCC_RF2

VCC_RF1

GND

RFIN

GC1

VCC_LO

+

1

2

3

4

5

6

ADDR

27

28

INTERFACE LOGIC

AND CONTROL

DIV2/DIV4

EP

SCL

VCC_BB

25

LPF BW

CONTROL

QDC-

DC OFFSET

CORRECTION

SDA

26 24 23

MAX2112

FREQUENCY

SYNTHESIZER

QDC+

IDC-

21

20

19

18

17

16

IDC+

IOUT-

IOUT+

QOUT-

QOUT+

VCC_DIG

VCC_VCO

XTAL

15

REFOUT

7

10 12

8

VCOBYP

9

VTUNE

11 132214

CPOUT

GNDSYN

GNDTUNE

VCC_SYN

MAX2112

Complete, Direct-Conversion
Tuner for DVB-S2 Applications

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(MAX2112 Evaluation Kit: V

CC

= +3.13V to +3.47V, TA= 0°C to +70°C (MAX2112CTI+), TA= -40°C to +85°C (MAX2112ETI+), V

GC1

= +0.5V (max gain), default register settings except BBG[3:0] = 1011. No input signals at RF, baseband I/Os are open circuited.
Typical values measured at V

CC

= +3.3V, TA= +25°C.) (Note 1)

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...........................................................-0.3V to +3.9V

All Other Pins to GND.................................-0.3V to (V

CC

+ 0.3V)

RF Input Power: RFIN .....................................................+10dBm

VCOBYP, CPOUT, XTAL, REFOUT, IOUT_, QOUT_ , IDC_,

QDC_ to GND Short-Circuit Protection...............................10s

Continuous Power Dissipation (T

A

= +70°C)

28-Pin Thin QFN (derated 34.5mW/°C above +70°C) ...2.75W

Operating Temperature Range (MAX2112CTI+) ......0°C to +70°C

Operating Temperature Range (MAX2112ETI+) ...-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10s) .................................+300°C

Soldering Temperature (reflow) .......................................+260°C

CAUTION! ESD SENSITIVE DEVICE

PARAMETER CONDITIONS MIN TYP MAX UNITS

SUPPLY

Supply Voltage 3.13 3.3 3.47 V

Supply Current

ADDRESS SELECT INPUT (ADDR)

Digital Input Voltage High, V

Digital Input Voltage Low, V

Digital Input Current High, I

Digital Input Current Low, I

ANALOG GAIN-CONTROL INPUT (GC1)

Input Voltage Range Maximum gain = 0.5V 0.5 2.7 V

Input Bias Current -50 +50 µA

VCO TUNING VOLTAGE INPUT (VTUNE)

Input Voltage Range 0.4 2.3 V

2-WIRE SERIAL INPUTS (SCL, SDA)

Clock Frequency 400 kHz

Input Logic-Level High

Input Logic-Level Low

Input Leakage Current Digital inputs = GND or V

2-WIRE SERIAL OUTPUT (SDA)

Output Logic-Level Low I

Receive mode, bit STBY = 0 100 160

Standby mode, bit STBY = 1 3

IH

IL

IH

IL

= 1mA 0.4 V

SINK

2.4 V

-50 µA

0.7 x
V

CC

CC

±0.1 ±1 µA

0.5 V

50 µA

0.3 x
V

CC

mA

V

V

MAX2112

Complete, Direct-Conversion

Tuner for DVB-S2 Applications

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS

(MAX2112 Evaluation Kit: V

CC

= +3.13V to +3.47V, TA= 0°C to +70°C (MAX2112CTI+), TA= -40°C to +85°C (MAX2112ETI+), default

register settings except BBG[3:0] = 1011. Typical values measured at V

CC

= +3.3V, TA= +25°C.) (Note 1)

PARAMETER CONDITIONS MIN TYP MAX UNITS

MAIN SIGNAL PATH PERFORMANCE

Input Frequency Range (Note 2) 925 2175 MHz

RF Gain-Control Range (GC1) 0.5V < V

Baseband Gain-Control Range Bits GC2 = 1111 to 0000 13 15 dB

In-Band Input IP3 (Note 3) +2 dBm

Out-of-Band Input IP3 (Note 4) +15 dBm

Input IP2 (Note 5) +40 dBm

Adjacent Channel Protection (Note 6) 25 dB

Noise Figure

Minimum RF Input Return Loss 925MHz < f

BASEBAND OUTPUT CHARACTERISTICS

Nominal Output Voltage Swing R

I/Q Amplitude Imbalance Measured at 500kHz; filter set to 22.27MHz ±1 dB

I/Q Quadrature Phase Imbalance Measured at 500kHz; filter set to 22.27MHz 3.5 D eg r ees

S i ng l e- E nd ed I/Q Outp ut Im p ed ance Real ZO, from 1MHz to 40MHz 30 Ω

Output 1dB Compression Voltage Differential 3 V

Baseband Highpass -3dB
Frequency Corner

BASEBAND LOWPASS FILTERS

Filter Bandwidth Range 4 40 MHz

Rejection Ratio At 2 x f

Group Delay Up to 1dB bandwidth 37 ns

Ratio of In-Filter-Band to Out-of­Filter-Band Noise

FREQUENCY SYNTHESIZER

RF-Divider Frequency Range 925 2175 MHz

RF-Divider Range (N) 19 251

Refer ence- D i vi d er Fr eq uency Rang e 12 30 MHz

Reference-Divider Range (R) 1 1

Phase-Detector Comparison
Frequency

VOLTAGE-CONTROLLED OSCILLATOR AND LO GENERATION

Guaranteed LO Frequency Range 925 2175 MHz

< 2.7V 65 73 dB

GC1

V

is set to 0.5V (maximum RF gain) and BBG[3:0] is

GC1

adjusted to give a 1V

-75dBm CW input tone at 1500MHz

Starting with the same BBG[3:0] setting as above, V
is adjusted to back off RF gain by 10dB (Note 7)

< 2175MHz, in 75Ω system 12 dB

RF

= 2kΩ//10pF 0.5 1 V

LOAD

47nF capacitors at IDC_, QDC_ 400 Hz

-3dB

f

112.5MHz

f

f

f

= 100Hz to 22.5MHz, f

INBAND

= 10kHz -97

OFFSET

= 100kHz -100LO Phase Noise

OFFSET

= 1MHz -122

OFFSET

baseband output level for a

P-P

GC1

OUTBAND

= 87.5MHz to

8

912

39 dB

25 dB

12 30 MHz

dB

P-P

P-P

dBc/Hz

MAX2112

Complete, Direct-Conversion
Tuner for DVB-S2 Applications

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2112 Evaluation Kit: V

CC

= +3.13V to +3.47V, TA= 0°C to +70°C (MAX2112CTI+), TA= -40°C to +85°C (MAX2112ETI+), default

register settings except BBG[3:0] = 1011. Typical values measured at V

CC

= +3.3V, TA= +25°C.) (Note 1)

Note 1: MAX2112CTI+: Min/max values are production tested at TA= +70°C. Min/max limits at TA= 0°C and TA= +25°C are

guaranteed by design and characterization.
MAX2112ETI+: Min/max values are production tested at T

A

= +85°C. Min/max limits at TA= -40°C and TA= +25°C are

guaranteed by design and characterization.

Note 2: Input gain range specifications met over this band.
Note 3: In-band IIP3 test conditions: GC1 set to provide the nominal baseband output drive when mixing down a -23dBm tone at

2175MHz to 5MHz baseband (f

LO

= 2170MHz). Baseband gain is set to its default value (BBG[3:0] = 1011). Two tones at

-26dBm each are applied at 2174MHz and 2175MHz. The IM3 tone at 3MHz is measured at baseband, but is referred to the
RF input.

Note 4: Out-of-band IIP3 test conditions: GC1 set to provide nominal baseband output drive when mixing down a -23dBm tone at

2175MHz to 5MHz baseband (f

LO

= 2170MHz). Baseband gain is set to its default value (BBG[3:0] = 1011). Two tones at

-20dBm each are applied at 2070MHz and 1975MHz. The IM3 tone at 5MHz is measured at baseband, but is referred to the
RF input.

Note 5: Input IP2 test conditions: GC1 set to provide nominal baseband output drive when mixing down a -23dBm tone at 2175MHz

to 5MHz baseband (f

LO

= 2170MHz). Baseband gain is set to its default value (BBG[3:0] = 1011). Two tones at -20dBm

each are applied at 925MHz and 1250MHz. The IM2 tone at 5MHz is measured at baseband, but is referred to the RF input.

Note 6: Adjacent channel protection test conditions: GC1 is set to provide the nominal baseband output drive with a 2110MHz

27.5Mbaud signal at -55dBm. GC2 set for mid-scale. The test signal shall be set for PR = 7/8 and SNR of -8.5dB. An adja­cent channel at ±40MHz is added at -25dBm. DVB-S BER performance of 2E-4 shall be maintained for the desired signal.
GC2 may be adjusted for best performance.

Note 7: Guaranteed by design and characterization at T

A

= +25°C.

Note 8: See Table 16 for crystal ESR requirements.

PARAMETER CONDITIONS MIN TYP MAX UNITS

XTAL/REFERENCE OSCILLATOR INPUT AND OUTPUT BUFFER

XTAL Oscillator Frequency Range Parallel-resonance-mode crystal (Note 8) 12 30 MHz

Input Overdrive level AC-coupled sine-wave input 0.5 1 2.0 V

XTAL Output-Buffer Divider Range 1 8

XTAL Output Voltage Swing 4MHz to 30MHz, C

XTAL Output Duty Cycle 50 %

= 10pF 1 1.5 2 V

LOAD

P-P

P-P

MAX2112

Complete, Direct-Conversion

Tuner for DVB-S2 Applications

_______________________________________________________________________________________

5

Typical Operating Characteristics

(MAX2112 Evaluation Kit: V

CC

= +3.3V, TA= +25°C, baseband output frequency = 5MHz; V

GC1

= +1.2V, default register settings

except BBG[3:0] = 1011.)

STANDBY MODE SUPPLY CURRENT

SUPPLY CURRENT vs. SUPPLY VOLTAGE

98

TA = +85°C

97

96

95

94

93

92

91

SUPPLY CURRENT (mA)

90

89

88

3.0 3.6

-10

-15

-20

-25

-30

-35

-40

-45

-50

BASEBAND 3RD-ORDER HARMONIC (dBc)

-55

-60

1.0 3.5

TA = +25°C

TA = -40°C

SUPPLY VOLTAGE (V)

HD3 vs. V

OUT

V

(V

)

OUT

P-P

QUADRATURE PHASE

3.53.43.33.23.1

3.02.52.01.5

3.0

2.9

MAX2112 toc01

2.8

2.7

2.6

2.5

SUPPLY CURRENT (mA)

2.4

2.3

93.5

92.5

MAX2112 toc04

91.5

90.5

89.5

88.5

QUADRATURE PHASE (°)

87.5

86.5

3.0 3.1 3.2 3.3 3.4 3.5 3.6

QUADRATURE PHASE vs. LO FREQUENCY

f

BASEBAND

900 1200 1500 1800 2100 2400

QUADRATURE MAGNITUDE MATCHING

vs. BASEBAND FREQUENCY

93.5

fLO = 925MHz

92.5

91.5

90.5

89.5

QUADRATURE PHASE (°)

88.5

87.5

86.5

020

BASEBAND FREQUENCY (MHz)

TA = +85°C

TA = +25°C

TA = -40°C

161284

1.0

fLO = 925MHz

0.8

MAX2112 toc06a

0.6

0.4

0.2

0

-0.2

-0.4

-0.6

-0.8

QUADRATURE MAGNITUDE MATCHING (dB)

-1.0
020

vs. SUPPLY VOLTAGE

TA = +85°C

TA = +25°C

TA = -40°C

SUPPLY VOLTAGE (V)

= 10MHz

TA = +25°C

TA = +85°C

TA = -40°C

LO FREQUENCY (MHz)

vs. BASEBAND FREQUENCY

TA = +85°C

TA = +25°C

BASEBAND FREQUENCY (MHz)

TA = -40°C

vs. BASEBAND FILTER CUTOFF FREQUENCY

104

102

MAX2112 toc02

100

98

96

94

92

90

SUPPLY CURRENT (mA)

88

86

84

440

QUADRATURE MAGNITUDE MATCHING

1.0

0.8

MAX2112 toc05a

0.6

0.4

0.2

0

-0.2

-0.4

-0.6

-0.8

QUADRATURE MAGNITUDE MATCHING (dB)

-1.0
900 2400

0

-10

MAX2112 toc06b

-20

-30

-40

-50

-60

BASEBAND OUTPUT LEVEL (dB)

-70

-80

161284

080

SUPPLY CURRENT

3628 32242016128

BASEBAND FILTER CUTOFF FREQUENCY (MHz)

vs. LO FREQUENCY

f

= 10MHz

BASEBAND

TA = +25°C

TA = -40°C

TA = +85°C

2100180015001200

LO FREQUENCY (MHz)

BASEBAND FILTER

FREQUENCY RESPONSE

604020

BASEBAND FREQUENCY (MHz)

MAX2112 toc03

MAX2112 toc05b

MAX2112 toc07

MAX2112

Complete, Direct-Conversion
Tuner for DVB-S2 Applications

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(MAX2112 Evaluation Kit: V

CC

= +3.3V, TA= +25°C, baseband output frequency = 5MHz; V

GC1

= +1.2V, default register settings

except BBG[3:0] = 1011.)

BASEBAND FILTER HIGHPASS

FREQUENCY RESPONSE

MAX2112 toc08

BASEBAND FREQUENCY (MHz)

BASEBAND OUTPUT LEVEL (dB)

1000

-10

-8

-4

-6

-2

0

2

-14

-12

100 10,000

PROGRAMMED f

-3dB

FREQUENCY

vs. MEASURED f

-3dB

FREQUENCY

MAX2112 toc09

PROGRAMMED f

-3dB

FREQUENCY (MHz)

MEASURED f

-3dB

FREQUENCY (MHz)

402015 25 30 35510

5

10

20

15

25

35

30

40

45

0

045

LPF[7:0] = 12 + (f

-3dB

- 4MHz)/290kHz

BASEBAND FILTER 3dB FREQUENCY

vs. TEMPERATURE

TEMPERATURE (°C)

BASEBAND GAIN ERROR AT f

-3dB

(dB)

MAX2112 toc10

-40-200 20406080

-1.0

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1.0

NORMALIZED TO TA = +25°C

INPUT POWER vs. V

GC1

V

GC1

(V)

INPUT POWER (dBm)

MAX2112 toc11

0.5 1.0 1.5 2.0 2.5 3.0

-80

-70

-60

-50

-40

-30

-20

-10

0

10

ADJUST BBG[3:0] FOR 1V

P-P

BASEBAND
OUTPUT WITH
P

IN

= -75dBm AND V

GC1

= 0.5V

TA = -40°C

TA = +85°C

TA = +25°C

NOISE FIGURE vs. FREQUENCY

FREQUENCY (MHz)

NOISE FIGURE (dB)

MAX2112 toc12

900 1100 1300 1500 1700 1900 2100 2300

7.5

8.0

8.5

9.0

9.5

10.0

10.5

TA = +25°C

TA = +85°C

ADJUST BBG[3:0] FOR 1V

P-P

BASEBAND

OUTPUT WITH P

IN

= -75dBm

AND V

GC1

= 0.5V

TA = +70°C

NOISE FIGURE vs. INPUT POWER

MAX2112 toc13

INPUT POWER (dBm)

NOISE FIGURE (dB)

-20-30-40-50-60-70

20

10

30

40

50

60

70

0

-80 0-10

ADJUST BBG[3:0] FOR 1V

P-P

BASEBAND OUTPUT WITH
P

IN

= -75dBm AND V

GC1

= 0.5V.

f

LO

= 1500MHz

OUT-OF-BAND IIP3 vs. INPUT POWER

MAX2112 toc14

INPUT POWER (dBm)

OUT-OF-BAND IIP3 (dBm)

-20-30-40-50-60-70

-10

-20

0

10

20

30

-30

-80 0-10

SEE NOTE 4 ON PAGE 4 FOR CONDITIONS

IN-BAND IIP3 vs. INPUT POWER

MAX2112 toc15

INPUT POWER (dBm)

IN-BAND IIP3 (dBm)

-20-30-40-50-60-70

-30

-50

-40

-10

-20

0

10

20

30

-60

-80 0-10

SEE NOTE 3 ON PAGE 4 FOR CONDITIONS

IIP2 vs. INPUT POWER

MAX2112 toc16

INPUT POWER (dBm)

IIP2 (dBm)

-20-30-40-50-60-70

0

10

30

20

40

50

60

-10

-80 0-10

SEE NOTE 5 ON PAGE 4 FOR CONDITIONS