
Maxim Integrated
General Description
The MAX2117 low-cost, direct-conversion tuner is intended for receiving MMDS transmissions in the 470MHz to 1000MHz band. The MAX2117 is designed to be used in consumer set-top boxes and is compatible with most DVB-S demodulators.
The MAX2117 directly converts the QPSK broadcast signals from the antenna to baseband using a broad band I/Q downconverter. The tuner provides differential I and Q outputs to the demodulator IC.
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 QPSK demodulators. The MAX2117 includes fully monolithic VCOs, as well as a complete 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 interface. The IC fea tures 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 interface, and buffer circuits active, providing a method to reduce power in single and multituner applications.
FEATUREs
♦ 470MHz to 1000MHz Frequency Range
♦ Monolithic VCO: No Calibration Required
♦ High Dynamic Range: -75dBm to 0dBm
♦ 4MHz to 40MHz Integrated Variable BW LP Filters
♦ Single +3.3V ±5% Supply
♦ Low-Power Standby Mode
♦ Address Pin for Multituner Applications
♦ Differential I/Q Interface
♦ I2C 2-Wire Serial Interface
♦ Very Small 28-Pin Thin QFN Package
APPLICATIONs
MMDS