max2769b通用GPS接收机

　　The MAX2769B is a next-generation Global Navigation Satellite System （GNSS） receiver covering GPS， GLONASS， Galileo， and Compass navigation satellite systems on a single chip. This single-conversion GNSS receiver is designed to provide high performance for industrial and automotive applications. Designed onMaxim’sadvanced， low-power SiGe BiCMOS process technology， the MAX2769B offers the highest performance and integration at a low cost. Incorporated on the chip is the complete receiver chain， including a dual-input LNA and mixer， followed by the image-rejected filter， PGA， VCO， fractional-N frequency synthesizer， crystal oscillator， and a multibitADC. The total cascaded noise figure of this receiver is as low as 1.4dB. The MAX2769B completely eliminates the need for external IF filters by implementing on-chip monolithic filters and requires only a few external components to form a complete low-cost GPS RF receiver solution. The MAX2769B is the most flexible receiver on the market. The integrated delta-sigma fractional-N frequency synthesizer allows programming of the IF frequency within a ±30Hz （fXTAL = 32MHz） accuracy while operating with any reference or crystal frequencies that are available in the host system. The ADC outputs CMOSlogiclevels with 1 or 2 quantized bits for both I and Q channels， or up to 3 quantized bits for the I channel. I and Qanalogoutputs are also available. The MAX2769B is packaged in a 5mm x 5mm， 28-pin thin QFN package with an exposed paddle.