Ultra-Wideband, Direct-Conversion, L-Band Satellite Tuner

The MAX2223 low-cost, direct-conversion tuner IC is de- signed for satellite set-top and very small aperture termi- nal (VSAT) applications. The device directly converts the satellite signals from the LNB to baseband using a broad- band I/Q downconverter. The operating frequency range extends from 925MHz to 2175MHz.

The device 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. The device supports 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 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 shutdown while leaving the reference oscillator, digital interface, and buffer circuits active, providing a method to reduce power in single and multituner applications.

A small number of passive components are needed to form a complete broadband satellite tuner DVB-S2 RF front-end solution. The tuner is available in a very small, 5mm x 5mm, 28-pin TQFN package.

Applications

* VSATs

* 925MHz to 2175MHz Frequency Range

* Monolithic VCO

* Low Phase Noise: -97dBc/Hz at 10kHz

* No Calibration Required

* High Dynamic Range: -75dBm to 0dBm

* 1GHz RF Bandwidth Supported

* Single +3.3V ±5% Supply

* Low-Power Standby Mode

* Address Pin for Multituner Applications

* Differential I/Q Interface

* I2C-Compatible, 2-Wire Serial Interface

* Very Small, 5mm x 5mm, 28-Pin TQFN Package