Rainbow Electronics MAX2105 User Manual
General description, Applications, Features

General Description
The MAX2102/MAX2105
†
are low-cost direct-conver-
sion tuner ICs designed for use in digital direct-broad-
cast 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 auto-
matic 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
LO
QDC
14
13
12
11
10
9
8
7
6
5
4
3
2
1
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Functional Diagram
19-1256; Rev 2; 10/98
PART
MAX2102
CWI
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 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX2105
CWI
0°C to +70°C
28 SO