SY89845UMG-TR

Signal Switches, Multiplexers, Decoders Overview

The SY89845UMG-TR is a Precision CML 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, supporting frequencies up to 1.5GHz. Key electrical parameters include propagation delays of 390ps to 840ps, output rise/fall times under 80ps, and jitter specifications of less than 1ps RMS random/cycle-to-cycle and 10ps peak-to-peak total jitter. The device features fail-safe input protection and accepts AC- or DC-coupled differential inputs as small as 100mV.

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 during signal failure
• Unique 3-pin input termination architecture for flexible AC/DC coupling without external resistors
• Ultra-low jitter design suitable for high-speed redundant source applications

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 the specific ordering suffix TR indicates tape and reel packaging configuration. Confirm the component meets RoHS compliance standards and lead finish requirements specified in the datasheet. Ensure the industrial temperature range (-40°C to +85°C) aligns with your system's operational environment before finalizing procurement.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when glitch-free transitions between asynchronous clocks are critical. It supports both AC and DC coupled interfaces including CML, PECL, and LVDS. The internal termination simplifies board layout by eliminating external resistor networks. Verify that the required power supply voltage matches either the 2.5V or 3.3V operating ranges defined in the specifications.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to Micrel’s Precision Edge product line, designed for high-speed timing applications. It integrates multiplexing, fanout buffering, and pulse elimination into a single 24-pin QFN package. The device replaces discrete logic solutions, reducing component count and board space while maintaining signal integrity in demanding digital environments.

Signal Switches, Multiplexers, Decoders Replacement Considerations

SY89843U

Signal Switches, Multiplexers, Decoders FAQ

How does the Fail-Safe Input function protect against signal loss?

If the selected input amplitude drops below 100mV single-ended or 200mV differential, the output latches to the last valid clock state, preventing oscillations or metastability.

What is the purpose of the CAP pin?

The CAP pin controls the Power-On Reset delay. Connecting a capacitor here ensures the RPE logic starts in a known state; tying it directly to VCC disables the RPE function.