资 源 简 介
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°C to +85°C.