ACS8525T

Overview

The Semtech ACS8525T is a highly integrated single-chip Line Card Protection Switch designed for SONET/SDH Network Elements. It provides hit-less protection switching for SEC and Sync clock groups from Master, Slave, and Stand-by sources. The device features fast activity monitors on SEC inputs to implement automatic system protection against clock failure. It supports frequency translation, converting inputs such as an 8 kHz SEC clock into higher frequencies like 155.52 MHz. The ACS8525 operates on a single 3.3 V supply with 5 V I/O compatibility and includes SPI-compatible serial configuration and IEEE 1149.1 JTAG boundary scan support.

Feature Summary

• Hit-less protection switching between three SEC/Sync input groups (Master, Slave, Stand-by) with automatic failover.
• Frequency translation capabilities supporting spot frequencies from 2 kHz up to 311.04 MHz via PECL/LVDS output.
• Digital Phase Locked Loop (DPLL) architecture ensuring stable performance across temperature and voltage variations.
• Supports Free-run, Locked, and Digital Holdover modes with programmable PLL bandwidths of 18, 35, or 70 Hz.

Applications

• SONET/SDH Line Cards
• Synchronous Equipment Timing Source (SETS) systems
• OC-3/STM-1 bit rate applications

Procurement Notes

Verify the ordering suffix 'T' indicates the lead-free, RoHS, and WEEE compliant version of the ACS8525. Confirm package type is LQFP 64. Check datasheet revision 3.01 for specific electrical characteristics and pin configurations.

Selection Notes

Select the ACS8525T when hit-less switching of SEC clock groups is required for line cards in SONET/SDH networks. Ensure the application requires support for TTL/CMOS and PECL/LVDS input technologies. Verify that the operating temperature range of -40°C to +85°C meets environmental requirements.

Part Context

The ACS8525T is part of the ACS8525 family of Line Card Protection Switches. It serves as a specialized component for telecommunications infrastructure, specifically addressing synchronization and redundancy needs in high-speed optical networking equipment.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult Semtech technical support for current equivalent products if the ACS8525T is obsolete.

FAQ

What input technologies does the ACS8525T support?

The Master and Slave SEC inputs support TTL/CMOS and PECL/LVDS technologies. The Stand-by SEC and all Sync inputs are TTL/CMOS only.

How does the ACS8525T handle clock failure?

It implements automatic system protection switching against Master clock failure using fast activity monitors. If both Master and Slave inputs fail, it selects the Stand-by group or enters Digital Holdover mode.

What is the maximum output frequency supported by the PECL/LVDS port?

The PECL/LVDS output port (O1) supports spot frequencies up to 311.04 MHz.