SY89844UMG-TR

Signal Switches, Multiplexers, Decoders Overview

The SY89844UMG-TR is a low jitter LVDS 2:1 input multiplexer optimized for redundant source switchover applications. It features a unique Runt Pulse Eliminator (RPE) to prevent short cycles during switching and Fail-Safe Input protection against metastable conditions. The device operates from a 2.5V ±5% supply, supports frequencies up to 2.0 GHz, and accepts AC- or DC-coupled inputs as small as 100mV without external termination networks. It provides glitch-free stable LVDS outputs with rise/fall times under 150ps.

Signal Switches, Multiplexers, Decoders Feature Summary

• Glitch-free switchover between two clock sources using the Runt Pulse Eliminator circuit
• Fail-Safe Input protection prevents metastable conditions when selected input amplitude drops below minimum limits
• Unique patent-pending input isolation design minimizes crosstalk
• Accepts AC- or DC-coupled differential signals (LVDS, CML, PECL) via internal 3-pin termination architecture

Signal Switches, Multiplexers, Decoders Applications

• Redundant clock switchover systems
• Fail-safe clock protection circuits
• Enterprise server infrastructure
• Test and measurement equipment

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify component authenticity through authorized Microchip Technology channels. Confirm package marking matches '844U' with Pb-Free indicator. Ensure ordering suffix '-TR' corresponds to tape and reel packaging. Validate RoHS compliance status prior to procurement integration.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component for designs requiring precise redundant clock management with minimal jitter. Verify that the 2.5V power supply requirement aligns with system voltage rails. Ensure the QFN-24 package footprint fits the PCB layout constraints. Confirm compatibility with LVDS output standards for downstream receivers.

Signal Switches, Multiplexers, Decoders Part Context

Part of Micrel's Precision Edge product line, now manufactured by Microchip Technology. Designed for high-speed digital interfaces requiring reliable signal integrity. Replaced legacy discrete solutions in redundant clock architectures. Supports industrial temperature ranges for robust operation in demanding environments.

Signal Switches, Multiplexers, Decoders Replacement Considerations

SY89843UMG-TR (LVPECL version), SY89845UMG-TR (CML version). Verify input/output voltage levels match target interface standards before substitution.

Signal Switches, Multiplexers, Decoders FAQ

How does the RPE function prevent runt pulses?

The RPE circuit ensures glitchless switchover by holding the output state during transitions, preventing short cycles that occur when switching between asynchronous clocks.

What happens if the selected input clock fails?

The Fail-Safe Input function latches the output to the last valid clock state, eliminating metastable conditions and oscillations caused by low-amplitude or floating inputs.