Satellite TV Tuner Elimnates Need For LNA

A low-cost, zero-IF, direct-conversion tuner for satellite TV, the MAX2120 from Maxim Integrated Products, receives quadrature phase-shift keying (QPSK) signals in the 925- to 2150-MHz range and downconverts them to baseband for demodulation. The device’s 8.0-dB noise figure eliminates the need for an external low-noise amplifier (LNA), while its voltage-controlled oscillator autotuner function ensures ease of use. The MAX2120 is well-suited for DVB-S and free-to-air applications in which low cost and ease of use are key requirements.

The tuner operates from a single 3.3-V supply and consumes only 330 mW. It's designed to function using a low-cost 4-MHz crystal, but an internal reference divider lets users select any crystal in the 4- to 8-MHz range. Fully specified over the 0°C to 70°C commercial temperature range, the MAX2120 is available in a 5- by 5-mm, 28-pin thin quad flat no-lead (TQFN) package. Evaluation kits and reference designs are available to speed designs.