19-0869; Rev 0; 8/07
Complete, Direct-Conversion
Tuner for DVB-S2 Applications
MAX12
General Description
Features
♦ 925MHz to 2175MHz Frequency Range
♦ Monolithic VCO
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.
Low Phase Noise: -97dBc/Hz at 10kHz
No Calibration Required
♦ High Dynamic Range: -75dBm to 0dBm
♦ Integrated Variable BW LP Filters: 4MHz to 40MHz
♦ Single +3.3V 5ꢀ Suꢁꢁly
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.
♦ Low-Power Standby Mode
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.
♦ Multiꢁle 2-Wire Addresses for Multituner
Aꢁꢁlications
♦ Differential I/Q Interface
2
♦ I C 2-Wire Serial Interface
♦ Very Small 28-Pin TQFN Package
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.
Ordering Information
PKG
PART
TEMP RANGE PIN-PACKAGE
CODE
0°C to +70°C 28 Thin QFN-EP* T2855+3
MAX2112CTI+
MAX2112ETI+ -40°C to +85°C 28 Thin QFN-EP* T2855+3
*EP = Exposed paddle.
+Denotes a lead-free package.
Pin Configuration/
Functional Diagram
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.
28
27
26
25
24
23
22
+
21
IDC+
VCC_RF2
VCC_RF1
1
2
3
DC OFFSET
CORRECTION
MAX2112
INTERFACE LOGIC
AND CONTROL
LPF BW
CONTROL
IOUT-
IOUT+
20
19
18
17
Applications
DirecTV and Dish Network DBS
GND
RFIN
GC1
DVB-S2
VSATs
QOUT-
QOUT+
4
5
FREQUENCY
SYNTHESIZER
DIV2/DIV4
VCC_LO
6
7
16 VCC_DIG
EP
VCC_VCO
15
REFOUT
8
9
10
11
12
13
14
________________________________________________________________ Maxim Integrated Products
1
For ꢁricing, delivery, and ordering information, ꢁlease contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.