MAX2117CTI+T Maxim Integrated Products, MAX2117CTI+T Datasheet - Page 10

• Manufacturer Part Number: MAX2117CTI+T
• Description: RF Receiver Direct Conversion Tu ner for MMDS -75 to
• Manufacturer: Maxim Integrated Products

Specifications of MAX2117CTI+T

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Complete DBS Direct-Conversion Tuner ICs
with Monolithic VCOs
The MAX2116/MAX2118 downconvert RF signals in the
850MHz to 2175MHz range directly to baseband I/Q sig-
nals. They are targeted for digital DBS tuner applications.
However, the MAX2116/MAX2118 are applicable to any
system requiring a broadband I/Q downconversion.
Internally, the MAX2116/MAX2118 consist of a broad-
band front-end LNA and variable gain stage, quadrature
downconverter, monolithic broadband VCOs, complete
frequency synthesizer, crystal reference oscillator and
buffer amplifier, programmable baseband lowpass fil-
ters, high-linearity I and Q baseband amplifiers, and off-
set correction amplifiers.
The MAX2116/MAX2118 feature a front-end VGA dynam-
ic range in excess of 60dB. Additionally, the baseband
VGA provides in excess of 19dB of additional gain con-
trol. The VSWR at RFIN is unaffected by the VGA setting.
The MAX2116/MAX2118 include completely monolithic
VCOs to cover the entire 850MHz to 2175MHz frequen-
cy range. The complete frequency range is covered
within a 5V tuning range, thus eliminating the need for
costly 30V supplies and varactor diodes. The VCO
architecture also eliminates problems associated with
frequency pulling with high receive input signal levels.
10
39, 40
______________________________________________________________________________________
PIN
34
35
36
37
38
—
IOUT - ( M AX2118)
N.C. (MAX2116)
QDC+, QDC-
Exposed Pad
IOUT/IOUT+
VCCRF2
QOUT+
VCCBB
NAME
Detailed Description
Noninverting Baseband Quadrature Output
DC Power Supply for Baseband Circuits. Connect to a 5V ±5% low-noise supply. Bypass with a
1nF capacitor directly to GND. Do not share vias.
No Connection. Pin should be connected directly to GND.
Inverting Baseband In-Phase Output
Noninverting Baseband In-Phase Output
DC Power Supply for RF Circuits and Second-Stage RF VGA Circuits. Connect to a 5V ±5% low-
noise supply. Bypass with a 1nF capacitor directly to GND. Do not share vias.
Q-Channel Baseband DC Offset Correction. Connect a 0.1µF ceramic chip capacitor from
QDC- to QDC+.
Ground
Adequate filtering of the VCC connection to the
VCCVCO supply pin is critical to achieve low phase noise
performance. See the Typical Operating Circuit .
The MAX2116/MAX2118 include programmable on-
chip 7th-order Butterworth lowpass filters. The filter
bandwidth is adjusted by setting two internal registers
(M, FDAC). The M counter should be set such that the
crystal frequency divided by M is between 1MHz and
2.5MHz. The FDAC register is then used to fine tune the
bandwidth. The -3dB cutoff frequency is determined by
the following equation:
where M and FDAC are decimals.
The filter can be adjusted from approximately 4MHz to
33MHz. Total device supply current is dependent on
the filter BW setting, with increasing current commensu-
rate with increasing 3dB BW.
The MAX2116 I/Q outputs are single-ended and opti-
mized for a nominal output voltage drive of 800mV
Output clipping levels are typically 2V
The MAX2118 I/Q outputs are differential, with two pos-
sible nominal output voltage levels. The nominal output
voltage swing is set through the DL bit Byte 04 (see
register table description). With DL = low, the nominal
output voltage swing is 590mV
f(3dB) = f
FUNCTION
Pin Description (continued)
Applications Information
XTAL
/ M
VCCVCO (Pin 13) Bypass
I/Q Output Voltage Level
✕
(4 + 0.145
P-P
differential; DL = high
Baseband LPFs
P-P
.
✕
FDAC)
P-P
.