Flexible Clock Translator for GPON, Base Station, SONET/SDH, T1/E1, and Ethernet

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 is 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.

APPLICATIONS

* Cost effective replacement of high frequency VCXO, OCXO, and SAW resonators

* Extremely flexible frequency translation for SONET/SDH, Ethernet, Fibre Channel, DRFI/DOCSIS, and PON/EPON/GPON

* Wireless infrastructure

* Test and measurement (including handheld devices)

* Input frequencies from 8 kHz to 710 MHz

* Output frequencies up to 810 MHz LVPECL and LVDS (up to 200 MHz for CMOS output)

* Preset pin-programmable frequency translation ratios cover popular wireline and wireless frequency applications, including xDSL, T1/E1, BITS, SONET, and Ethernet.

* Arbitrary frequency translation ratios via SPI port

* On-chip VCO