Semtech expands line card clock switch portfolio

Semtech Corp. has expanded its Synchronous Equipment Timing Source family of Stratum 3-compliant line card clock switches with the addition of three new single-chip devices that provide the line card protection switching and clock synthesis function in PDH, SONET, or SDH networks.

The ACS8525, ACS8526, and ACS8527 employ a patented, phase detector technique, and a mixed analog and digital PLL architecture to protect ADMs, switches, cross-connects, core routers, and DSLAMs. The cards are suited for retrofitting existing systems that require the addition or increasing synchronization capability.

In addition, the ACS8525 incorporates protection switching for both the synchronization reference clock and the associated Frame Sync for "group switching" which enables simultaneous switching of multiple line cards. It also allows an input source switch to be initiated automatically upon fast detection of a failure with the input reference.

The ACS8525 and ACS8526 line card protection devices simultaneously generate multiple output clocks with a choice of up to 55 different frequencies including n x E1, n x DS1, E3, DS3 rates, and standard OC-n rates up to 155.52MHz or 311.08MHz with 2kHz and 8kHz frame synchronization clocks. The ACS8527 device generates 11 standard rates.

Pin-compatible with a LQFP64 package, the switches has a holdover accuracy of 1.2x10^-6ppm and exhibit a typical output phase disturbance of <2.5ns.