GPON»ù´¡Áé»îµÄʱÖÓת»»Æ÷SDHºÍÒÔÌ«Íøad9553Êý¾Ý±í

¡¡¡¡The AD9553 is a phase-locked loop £¨PLL£© based clock translator designed to address the needs of passive optical networks £¨PON£© and base stations. The device employs an integer-N PLL to accommodate the applicable frequency translation requirements. The user supplies up to two single-ended input reference signals or one differential input reference signal via the REFA and REFB inputs. The device supports holdover applications by allowing the user to connect a 25 MHz crystal resonator to the XTAL input. The AD9553 is pin programmable£¬ providing a matrix of standard input/output frequency translations from a list of 15 possible input frequencies to a list of 52 possible output frequency pairs £¨OUT1 and OUT2£©¡£ The device also has a 3-wire SPI interface£¬ enabling the user to program custom input-to-output frequency translations. The AD9553 output drivers are compatible with LVPECL£¬ LVDS£¬ or single-ended CMOS logic levels£¬ although the AD9553 is implemented in a strictly CMOS process. The AD9553 operates over the extended industrial temperature range of ?40¡ãC to +85¡ãC.