Maxim Integrated MAX2223 Direct Conversion L-Band Satellite Tuner

Maxim MAX2223 Direct Conversion L-Band Satellite Tuner is designed for satellite set-top and Very Small Aperture Terminal (VSAT) applications. The device directly converts the satellite signals from the LNB to baseband using a broadband I/Q down-converter. The operating frequency range extends from 925MHz to 2175MHz. MAX2223 includes an LNA and an RF variable-gain amplifier I and Q down-converting mixers and baseband amplifiers. The RF variable-gain amplifier provides more than 70dB of gain control range and an RF bandwidth of 1GHz. The device 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 interface. The IC features a VCO auto-select (VAS) function that automatically selects the proper VCO. For multi-tuner applications the device can be configured to have one of two 2-wire interface addresses. A low-power standby mode is available when the signal path is shutdown while leaving the reference oscillator digital interface and buffer circuits active. This provides a method to reduce power in single and multi-tuner applications.