Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsMAX2112CTI+

AVAILABLE

EVALUATION KIT AVAILABLE

Functional Diagrams

Pin Configurations appear at end of data sheet.

Functional Diagrams continued at end of data sheet.

UCSP is a trademark of Maxim Integrated Products, Inc.

For pricing, delivery, and

ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

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 I

C 2-Wire Serial Interface

o Very Small 28-Pin TQFN Package

Complete, Direct-Conversion

Tuner for DVB-S2 Applications

VTUNE

GNDSYN

CPOUT

VCC_SYN

XTAL

VCOBYP

SCL

VCC_BB

QDC-

ADDR

QDC+

IDC-

RFIN

GC1

VCC_LO

IOUT+

QOUT-

VCC_DIG

GNDTUNE

SDA

VCC_VCO

REFOUT

GND

IOUT-

VCC_RF1

IDC+

26 24 23

10 12

11 13

VCC_RF2

MAX2112

INTERFACE LOGIC

AND CONTROL

DC OFFSET

CORRECTION

LPF BW

CONTROL

DIV2/DIV4

FREQUENCY

SYNTHESIZER

QOUT+

Pin Configuration/

Functional Diagram

Ordering Information

EP = Exposed paddle.

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

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*

MAX2112

19-0869; Rev 2; 5/10

Summary of content (19 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications LE AVAILAB General Description Features 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.
PAGE 2
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications ABSOLUTE MAXIMUM RATINGS VCC to GND ...........................................................-0.3V to +3.9V All Other Pins to GND.................................-0.3V to (VCC + 0.3V) RF Input Power: RFIN .....................................................+10dBm VCOBYP, CPOUT, XTAL, REFOUT, IOUT_, QOUT_ , IDC_, QDC_ to GND Short-Circuit Protection...............................
PAGE 3
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications AC ELECTRICAL CHARACTERISTICS (MAX2112 Evaluation Kit: VCC = +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 VCC = +3.3V, TA = +25°C.) (Note 1) PARAMETER CONDITIONS MIN TYP MAX UNITS 2175 MHz MAIN SIGNAL PATH PERFORMANCE Input Frequency Range (Note 2) 925 RF Gain-Control Range (GC1) 0.5V < VGC1 < 2.
PAGE 4
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications AC ELECTRICAL CHARACTERISTICS (continued) (MAX2112 Evaluation Kit: VCC = +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 VCC = +3.3V, TA = +25°C.) (Note 1) PARAMETER CONDITIONS MIN TYP MAX UNITS 30 MHz 1 2.0 VP-P 1.
PAGE 5
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Typical Operating Characteristics (MAX2112 Evaluation Kit: VCC = +3.3V, TA = +25°C, baseband output frequency = 5MHz; VGC1 = +1.2V, default register settings except BBG[3:0] = 1011.) STANDBY MODE SUPPLY CURRENT vs. SUPPLY VOLTAGE 94 93 92 TA = -40°C 2.8 2.7 TA = +25°C 2.6 2.5 90 88 3.3 3.4 3.5 SUPPLY VOLTAGE (V) HD3 vs. VOUT QUADRATURE PHASE vs. LO FREQUENCY 3.0 -25 -30 -35 -40 -45 3.5 MAX2112 toc05a TA = +25°C 91.
PAGE 6
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Typical Operating Characteristics (continued) (MAX2112 Evaluation Kit: VCC = +3.3V, TA = +25°C, baseband output frequency = 5MHz; VGC1 = +1.2V, default register settings except BBG[3:0] = 1011.) -8 -10 25 20 15 10 -12 5 -14 0 5 INPUT POWER vs. VGC1 MAX2112 toc11 TA = +25°C -30 -40 TA = +85°C TA = -40°C 10 15 20 25 30 35 40 -50 -40 TA = +85°C 9.5 9.0 TA = +70°C 8.5 60 -80 3.
PAGE 7
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Typical Operating Characteristics (continued) (MAX2112 Evaluation Kit: VCC = +3.3V, TA = +25°C, baseband output frequency = 5MHz; VGC1 = +1.2V, default register settings except BBG[3:0] = 1011.) PHASE NOISE AT 10kHz OFFSET vs. CHANNEL FREQUENCY INPUT RETURN LOSS vs. FREQUENCY MAX2112 toc17 VGC1 = 0.5V -10 -15 -20 VGC1 = 2.
PAGE 8
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Pin Description 8 PIN NAME FUNCTION 1 VCC_RF2 DC Power Supply for LNA. Connect to a +3.3V low-noise supply. Bypass to GND with a 1nF capacitor connected as close as possible to the pin. Do not share capacitor ground vias with other ground connections. 2 VCC_RF1 DC Power Supply for LNA. Connect to a +3.3V low-noise supply. Bypass to GND with a 1nF capacitor connected as close as possible to the pin.
PAGE 9
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Pin Description (continued) PIN NAME FUNCTION 26 SDA 2-Wire Serial-Data Interface. Requires ≥ 1kΩ pullup resistor to VCC. 27 SCL 2-Wire Serial-Clock Interface. Requires ≥ 1kΩ pullup resistor to VCC. 28 ADDR — EP Address. Must be connected to either ground (logic 0) or supply (logic 1). Exposed Paddle. Solder evenly to the board’s ground plane for proper operation.
PAGE 10
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Table 2. N-Divider MSB Register BIT NAME BIT LOCATION (0 = LSB) DEFAULT FRAC 7 1 N[14:8] 6–0 0000000 FUNCTION Users must program to 1 upon powering up the device. Sets the most significant bits of the PLL integer-divide number (N). N can range from 19 to 251. Table 3. N-Divider LSB Register BIT NAME BIT LOCATION (0 = LSB) DEFAULT FUNCTION N[7:0] 7–0 00100011 Sets the least significant bits of the PLL integer-divide number.
PAGE 11
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Table 8. PLL Register BIT NAME BIT LOCATION (0 = LSB) DEFAULT FUNCTION D24 7 1 VCO divider setting. 0 = Divide by 2. Use for LO frequencies ≥ 1125MHz. 1 = Divide by 4. Use for LO frequencies < 1125MHz. CPS 6 1 Charge-pump current mode. 0 = Charge-pump current controlled by ICP bit. 1 = Charge-pump current controlled by VCO autoselect (VAS). ICP 5 0 Charge-pump current. 0 = 600µA typical. 1 = 1200µA typical.
PAGE 12
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Table 11. Control Register BIT NAME BIT LOCATION (0 = LSB) DEFAULT FUNCTION STBY 7 0 Software standby control. 0 = Normal operation. 1 = Disables the signal path and frequency synthesizer leaving only the 2-wire bus, crystal oscillator, XTALOUT buffer, and XTALOUT buffer divider active. X 6 X Don’t care. PWDN 5 0 Factory use only. 0 = Normal operation; other value is not tested. X 4 X Don’t care.
PAGE 13
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Table 13. Test Register BIT NAME BIT LOCATION (0 = LSB) DEFAULT FUNCTION CPTST[2:0] 7–5 000 X 4 X Don’t care. TURBO 3 0 Charge-pump fast lock. Users must program to 1 after powering up the device. LDMUX[2:0] 2–0 000 Charge-pump test modes. 000 = Normal operation (default). REFOUT output. 000 = Normal operation. Other values are not tested. Table 14.
PAGE 14
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications 2-Wire Serial Interface The MAX2112 uses a 2-wire I2C-compatible serial interface consisting of a serial-data line (SDA) and a serialclock line (SCL). SDA and SCL facilitate bidirectional communication between the MAX2112 and the master at clock frequencies up to 400kHz. The master initiates a data transfer on the bus and generates the SCL signal to permit data transfer.
PAGE 15
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications S T A R T DEVICE ADDRESS R/W 1100000 0 A C K REGISTER ADDRESS 00000000 S T A R T A C K DEVICE ADDRESS R/W 1100000 1 A C K REG 00 DATA xxxxxxxx A C K REG 01 DATA xxxxxxxx A C K REG 02 DATA xxxxxxxx N A C K S T O P Figure 3. Example: Receive Data from Read Registers Read Cycle When addressed with a read command, the MAX2112 allows the master to read back a single register, or multiple successive registers.
PAGE 16
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Alternatively, the MAX2112 can be set to autonomously choose a VCO by setting the VAS bit in the VCO register to logic-high. The VAS routine is initiated once the F-Divider LSB register word (REG 5) is loaded. In the event that only the N-divider register or F-divider MSB word is changed, the F-divider LSB word must also be loaded last to initiate the VCO autoselect function.
PAGE 17
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Typical Application Circuit SERIAL-DATA INPUT/OUTPUT VCC + VCC_RF2 VCC 28 27 26 1 25 IDC- QDC+ QDC24 23 22 IOUT- LPF BW CONTROL 2 IDC+ 21 DC OFFSET CORRECTION MAX2112 INTERFACE LOGIC AND CONTROL VCC_RF1 VCC_BB VCC SDA SCL ADDR SERIAL-CLOCK INPUT 20 IOUT+ GND 19 3 QOUT- RF INPUT RFIN VGC GC1 18 4 QOUT+ 5 17 VCC FREQUENCY SYNTHESIZER DIV2 /DIV4 VCC_LO VCC 6 16 VCC VCC_DIG EP REFOUT VCC_VCO 15 7
PAGE 18
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Package Information Chip Information PROCESS: BiCMOS 18 For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
PAGE 19
MAX2112 Complete, Direct-Conversion Tuner for DVB-S2 Applications Revision History REVISION NUMBER REVISION DATE DESCRIPTION 0 8/07 Initial release 1 12/07 Corrected errors in data sheet 2 5/10 Corrected errors in FUNCTION cells of Tables 8 and 10, corrected formula in Baseband Lowpass Filter section PAGES CHANGED — 1–7, 9–16 11, 15 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.