SY89841UMG-TR

Signal Switches, Multiplexers, Decoders Overview

The SY89841UMG-TR is a Precision LVDS Runt Pulse Eliminator 2:1 multiplexer manufactured by Microchip Technology. It operates from a single 2.5V ±5% supply (2.375V to 2.625V) and supports frequencies up to 1.5GHz. The device features <870ps propagation delay, <150ps rise/fall times, and ultra-low jitter (<1ps rms random). It includes unique RPE logic for glitch-free switchover and Fail-safe Input protection against metastable conditions. Packaged in a 16-pin MLF (3x3mm) surface-mount format.

Signal Switches, Multiplexers, Decoders Feature Summary

• Runt Pulse Eliminator (RPE) logic ensures glitch-free switchover between two clock sources without generating short cycles or runt pulses.
• Fail-safe Input (FSI) circuit prevents metastable output conditions when the selected differential input signal amplitude drops below minimum thresholds.
• Unique 3-pin input termination architecture allows direct interfacing with AC-coupled or DC-coupled signals as small as 100mV without external level shifting or termination networks.
• Ultra-low jitter design guarantees stable LVDS outputs with fast rise and fall times suitable for high-speed redundant clock applications.

Signal Switches, Multiplexers, Decoders Applications

• Redundant clock switchover systems
• Fail-safe clock protection circuits
• LAN/WAN infrastructure equipment
• Enterprise server timing architectures

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify that the component is sourced from authorized distributors to ensure authenticity. Confirm the package marking matches the specified industrial grade and lead finish. Check for RoHS compliance documentation if required by your manufacturing standards. Ensure the ordering suffix corresponds to the tape and reel configuration needed for your assembly process.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when glitch-free transition between asynchronous or synchronous clock sources is critical. It is suitable for designs requiring low jitter performance and simplified input interface topologies. Consider the specific power-on reset capacitor requirements for the CAP pin if utilizing the RPE function during system initialization.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to Micrel’s Precision Edge product line, now under Microchip Technology following acquisition. It is designed specifically for high-speed digital applications requiring reliable clock distribution. The device integrates advanced isolation and termination features to simplify PCB layout and improve signal integrity in dense electronic systems.

Signal Switches, Multiplexers, Decoders Replacement Considerations

SY89841UMG is the non-tape and reel variant of the same functional device. Verify package compatibility and lead finish specifications when substituting. No other cross-model replacements are confirmed in the provided documentation.

Signal Switches, Multiplexers, Decoders FAQ

How does the SY89841UMG-TR prevent runt pulses during clock switchover?

The device uses internal Runt Pulse Eliminator (RPE) logic that controls the switchover sequence in stages, ensuring the output remains stable and free of short cycles or glitches during the transition between primary and secondary clocks.

What happens if the selected input clock fails to a DC voltage?

The Fail-safe Input (FSI) circuit detects when the differential input voltage drops below 100mV and latches the output to the last valid clock state, preventing oscillations or metastable conditions at the output.

Can the SY89841UMG-TR accept DC-coupled inputs?

Yes, the unique 3-pin input termination architecture allows the device to interface directly with DC-coupled signals (such as CML or LVPECL) without requiring external termination resistor networks or level shifting.