SY58028UMI

Signal Switches, Multiplexers, Decoders Overview

The SY58028UMI is a high-speed, precision differential CML multiplexer manufactured by Microchip Technology. It selects one of four differential inputs and provides two copies via a 1:2 fanout buffer. The device supports data rates up to 10.7Gbps and clock frequencies up to 7GHz. It operates from a 2.5V ±5% or 3.3V ±10% power supply within an industrial temperature range of –40°C to +85°C. Propagation delay is guaranteed at less than 350ps, with rise/fall times under 60ps. Total jitter is specified at less than 10ps peak-to-peak.

Signal Switches, Multiplexers, Decoders Feature Summary

• Accepts AC- or DC-coupled differential signals as low as 100mV without external level shifting or termination networks
• Features unique internal input termination architecture for maximum interface flexibility
• Provides ultra-low-jitter performance suitable for precise timing applications
• Outputs are internally source terminated CML with extremely fast edge rates

Signal Switches, Multiplexers, Decoders Applications

• Redundant clock and/or data distribution
• SONET/SDH clock and data distribution
• Fibre Channel distribution
• Gigabit Ethernet clock and data distribution

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the specific ordering suffix to confirm package type and lead finish. The 'MI' suffix indicates the MLF-32 package with Sn-Pb (lead-based) finish. For lead-free requirements, select the 'MG' suffix variant. Confirm moisture sensitivity handling during storage and assembly. Ensure the application design accounts for the exposed pad thermal connection requirements specified in the datasheet.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when interfacing with CML, LVDS, or LVPECL sources requiring minimal signal path components. The internal 50Ω input termination simplifies board layout compared to discrete resistor solutions. Consider the SY58029U if LVPECL outputs are required instead of CML. Verify that the 400mV output swing matches the receiving device's input threshold requirements.

Signal Switches, Multiplexers, Decoders Part Context

The SY58028U belongs to Micrel’s Precision Edge product line, designed for high-speed digital interfaces. It is part of a family including the SY58029U and SY58030U, which offer similar multiplexing functions but with different output logic levels. This series targets telecommunications and networking infrastructure requiring low jitter and high throughput.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Public confirmed substitute part numbers include SY58028UMITR, SY58028UMG, and SY58028UMGTR. These variants share identical functionality but differ in packaging format (Tape and Reel vs. Tube) and lead finish composition (Lead-Free vs. Sn-Pb).

Signal Switches, Multiplexers, Decoders FAQ

How should unused differential input pairs be handled?

Unused input pairs should have one pin connected to ground through a 1kΩ resistor and the complement pin connected to VCC through an 825Ω resistor. Unused VT and VREF-AC pins may be left open.

What is the function of the VT pin?

The VT pin serves as the center-tap for the internal 50Ω input termination network, providing flexibility for various input coupling methods.

Can the device accept LVDS inputs directly?

Yes, the device accepts LVDS inputs. The documentation specifies an interface configuration where the VT pin is left NC (No Connect) for direct LVDS coupling.