SY89841UMG

Overview

The SY89841UMG is a Precision LVDS Runt Pulse Eliminator 2:1 multiplexer designed for redundant source switchover applications. It operates from a 2.5V ±5% supply within an industrial temperature range of –40°C to +85°C. The device supports maximum operating frequencies up to 2.0 GHz, with propagation delays ranging from 470 ps to 900 ps depending on input voltage swing and RPE status. Output rise/fall times are guaranteed under 150 ps. Jitter performance includes less than 1 ps rms random jitter and less than 10 ps peak-to-peak total jitter.

Feature Summary

• Runt Pulse Eliminator (RPE) circuit prevents short cycles or runt pulses during clock switchover transitions
• Fail-safe Input (FSI) protection prevents metastable conditions when selected input clocks fail to DC voltages
• Unique 3-pin input termination architecture allows interfacing with AC- or DC-coupled signals as small as 100mV without external level shifting or termination networks
• Ultra-low jitter design ensures stable differential LVDS outputs with fast rise and fall times

Applications

• Redundant clock switchover systems
• Fail-safe clock protection circuits
• LAN/WAN infrastructure equipment
• Enterprise server timing distribution
• Automated Test Equipment (ATE)

Procurement Notes

Verify the specific ordering suffix required for your packaging needs. The SY89841UMG is supplied in tubes, while the SY89841UMGTR variant utilizes tape and reel packaging. Confirm that the NiPdAu lead finish and MLF-16 package type align with your assembly process requirements before finalizing procurement orders.

Selection Notes

Select this component when glitch-free switchover between two asynchronous clock sources is critical. The internal RPE logic requires an external capacitor on the CAP pin to initialize correctly; ensure this is included in the design if runt pulse elimination is needed. Verify that input signal amplitudes meet the minimum 100mV requirement for proper operation of the unique input termination architecture.

Part Context

This device belongs to Micrel’s Precision Edge product line, which focuses on high-speed, low-jitter signal conditioning components. The SY89841U specifically addresses the need for reliable clock redundancy in high-frequency digital systems by combining multiplexing functionality with advanced pulse elimination and fail-safe protection mechanisms.

Replacement Considerations

The SY89840U serves as a related product offering similar Runt Pulse Eliminator functionality but utilizes LVPECL signaling instead of LVDS. Designers requiring CML interface compatibility should consider the SY89842U. Ensure output voltage swing and input logic levels match the target system requirements when evaluating these alternatives.