SY89843UMG-TR

Signal Switches, Multiplexers, Decoders Overview

The SY89843UMG-TR is a Precision LVPECL Runt Pulse Eliminator (RPE) 2:1 multiplexer with 1:2 fanout and internal termination. It operates from a 2.5V ±5% or 3.3V ±10% supply within an industrial temperature range of –40°C to +85°C. The device supports frequencies up to 2.0 GHz, featuring propagation delays under 880ps and rise/fall times below 190ps. It delivers 65fs RMS phase jitter and includes fail-safe input protection against metastable conditions.

Signal Switches, Multiplexers, Decoders Feature Summary

• Unique Runt Pulse Eliminator (RPE) circuit prevents short cycles during redundant source switchover
• Fail-Safe Input protection prevents metastable conditions when selected clock fails to DC voltage
• Patent-pending 3-pin input termination architecture accepts AC- or DC-coupled signals as small as 100mV without external level shifting
• Ultra-low jitter design with guaranteed AC performance over temperature and supply voltage variations

Signal Switches, Multiplexers, Decoders Applications

• Redundant clock switchover
• Failsafe clock protection
• LAN/WAN systems
• Enterprise servers
• Automated Test Equipment (ATE)

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the component originates from authorized Microchip Technology channels to ensure authenticity. Confirm the specific ordering suffix matches the required tape and reel packaging configuration. Check for RoHS compliance status and lead finish specifications prior to integration into manufacturing processes.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component for applications requiring glitch-free switchover between two differential clock sources. Ensure the system power supply ramps up correctly to support the Power-On Reset capacitor requirements on the CAP pin. Verify that the input signal amplitude meets the minimum threshold for the internal termination network to function effectively.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to Micrel’s Precision Edge product line, now manufactured by Microchip Technology. It is designed for high-speed digital interfaces requiring stable clock distribution. The QFN-24 package provides a compact footprint suitable for dense PCB layouts in enterprise and communication infrastructure equipment.

Signal Switches, Multiplexers, Decoders Replacement Considerations

SY89844U

Signal Switches, Multiplexers, Decoders FAQ

How does the Fail-Safe Input (FSI) function operate?

The FSI function protects against selected input pairs dropping below the minimum amplitude requirement. If the differential input voltage falls below 100mV single-ended or 200mV differentially, the output latches to the last valid clock state to prevent oscillations.

What is the purpose of the CAP pin?

The CAP pin controls the Power-On Reset (POR) initialization delay. Connecting a capacitor to VCC ensures the internal RPE logic starts in a known state. Tying it directly to VCC disables the RPE function, allowing immediate switchover.