DS3105LN

Overview

The DS3105LN is a line card timing integrated circuit manufactured by Microchip Technology. Designed for Ethernet, SONET/SDH, Stratum, and telecom applications, it features advanced DPLL technology with programmable PLL bandwidths ranging from 18 Hz to 400 Hz. The device supports hitless reference switching and automatic holdover upon loss of all input references. It accepts multiple input clock frequencies including CMOS, LVDS, LVPECL, and TTL signals, delivering outputs up to 312.5 MHz. Operating on a 1.62V to 1.98V supply within a -40°C to 85°C temperature range, it is housed in a 64-LQFP (10x10) surface-mount package.

Feature Summary

• Advanced DPLL technology with programmable PLL bandwidth from 18 Hz to 400 Hz
• Hitless reference switching and automatic/manual holdover capabilities
• Supports frequency conversion among SONET/SDH, PDH, Ethernet, wireless, and CMTS rates
• Five input clocks: two CMOS/TTL (≤125 MHz), two LVDS/LVPECL/CMOS/TTL (≤156.25 MHz), and one backup CMOS/TTL

Applications

• SONET/SDH network equipment
• Synchronous Ethernet systems (1G, 10G, 100Mb/s)
• Wireless base stations
• CMTS systems
• PDH networks

Procurement Notes

Verify the specific suffix 'LN' against official Microchip documentation to confirm pinout compatibility and electrical characteristics relative to the base DS3105 model. Ensure the 64-LQFP package dimensions match the target PCB footprint. Confirm that the 1.62V–1.98V supply voltage aligns with the system power design before procurement.

Selection Notes

Select this component when designing telecom line cards requiring precise timing synchronization for SONET/SDH or Synchronous Ethernet. The device is suitable for applications needing flexible input/output frequency ratios and robust reference switching. Consider the 64-LQFP package size and thermal requirements for -40°C to 85°C operation during layout planning.

Part Context

The DS3105LN belongs to the DS3105 family of line card timing ICs. This series is designed to replace older solutions like the Semtech ACS8525, offering backward-compatible register sets while providing enhanced features such as wider PLL bandwidth control and additional input options for modern telecom infrastructure.

Replacement Considerations

The DS3105 offers backward compatibility with the Semtech ACS8525 in terms of register set, though pinouts differ. Verify pin-to-pin compatibility if substituting directly into existing designs originally built around the ACS8525.