ACS8514T

Overview

The ACS8514 is a Synchronous Equipment Timing Source (SETS) partner IC designed for use with Semtech ACS8520 and ACS8530 devices. It provides an additional independent T4 path DPLL to support dual T4 synchronization architectures defined in Bellcore GR-253 Figure 5-21. The device accepts 14 input reference clocks, including AMI composite, LVDS/PECL, and TTL/CMOS signals, and generates two output clocks derived from the T4 DPLL. It features a dedicated Monitor DPLL for high-accuracy phase and frequency analysis, supporting measurements down to 0.7 degrees and 0.0003 ppm.

Feature Summary

• Provides an additional BITS clock (T4 path) DPLL for systems requiring two independent T4 paths per GR-253 standards.
• Includes a Monitor DPLL capable of measuring phase accuracy to 0.7 degrees and frequency accuracy to 3x10^-10.
• Accepts 14 individual input reference clocks with robust quality monitoring and automatic source selection.
• Supports multiple microprocessor interfaces including Intel, Motorola, Serial, Multiplexed, and EPROM boot modes.

Applications

• SONET Minimum Clock (SMC) applications
• SONET/SDH Equipment Clock (SEC) implementations
• Clock synchronization systems requiring dual T4 paths
• Input extenders for expanding clock source selection beyond primary SETS limits

Procurement Notes

Verify the specific ordering suffix 'T' indicates the lead-free version compliant with RoHS and WEEE directives. Confirm package availability and revision status against the April 2007 datasheet. Ensure supply chain sources provide documentation confirming the component matches the ACS8514 specification without functional deviations due to packaging changes.

Selection Notes

Select the ACS8514 when a system design requires two independent T4 paths or needs to extend input clock selection capabilities beyond the primary ACS8520/30 limits. The device is suitable for applications demanding precise phase and frequency monitoring of standby clock references. Ensure the host processor supports one of the compatible interface modes: Intel, Motorola, Serial, Multiplexed, or EPROM.

Part Context

The ACS8514 functions as a specialized companion to the ACS8520 and ACS8530 SETS ICs. It is part of Semtech's advanced comms and sensing portfolio focused on clock synchronization. The device enables complex timing architectures by adding independent DPLL paths and enhanced monitoring capabilities to standard synchronous equipment designs.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. The ACS8514 is designed specifically to partner with ACS8520 and ACS8530 devices; alternative components must be evaluated for compatibility with these specific host controllers and GR-253 compliance requirements.

FAQ

What is the primary function of the ACS8514 in a clock synchronization system?

It adds an additional BITS clock (T4 path) DPLL to allow systems to have two totally independent T4 paths, complying with configurations defined in Bellcore GR-253 Figure 5-21.

How many input reference clocks does the ACS8514 accept?

The device accepts 14 individual input reference clocks, which can include AMI composite, LVDS/PECL, and TTL/CMOS signals.

What is the phase measurement accuracy of the Monitor DPLL?

The Monitor DPLL provides phase measurement accuracy to 0.7 degrees, with a range up to 23,000 degrees.