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 inter-

face. 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 inter-

face, and buffer circuits active, providing a method to

reduce power in single and multituner applications.

The MAX2112 is the most advanced DBS tuner avail-

able today. The low noise figure eliminates the need for

an external LNA. A small number of passive compo-

nents are needed to form a complete DVB-S2 RF front-

end 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 Very Small 28-Pin TQFN Package

Complete, Direct-Conversion

Tuner for DVB-S2 Applications

________________________________________________________________

Maxim Integrated Products

1

RFIN

GC1

VCC_LO

+

IOUT+

QOUT-

VCC_DIG

19

17

16

3

5

18

4

6

VCC_VCO

REFOUT

15

7

GND

IOUT-

20

2

VCC_RF1

21

IDC+

1

26

24

23

10

12

25

11

13

22

14

27

9

28

8

VCC_RF2

MAX2112

INTERFACE LOGIC

AND CONTROL

DC OFFSET

CORRECTION

LPF BW

CONTROL

DIV2/DIV4

EP

FREQUENCY

SYNTHESIZER

QOUT+

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*