SY58621LMG

Overview

The SY58621LMG is a high-speed transceiver from Micrel's Precision Edge line, designed for backplane and transmission line data management. It operates on a single +3.3V ±10% supply within the industrial temperature range of –40°C to +85°C. The device supports a maximum throughput of 3.2Gbps with deterministic jitter under 13ps peak-to-peak and random jitter below 0.75ps RMS. It features a variable swing LVPECL transmitter output (80mV to 800mV) and a CML receiver output (400mV differential). The package is a 24-pin QFN.

Feature Summary

• Patented three-pin input termination architecture enabling direct interface to AC- or DC-coupled signals without external termination networks in the signal path.
• Selectable internal loopback diagnostic mode that connects the transmitter input directly to the receiver output for remote self-testing.
• Programmable Loss-of-Signal (LOS) detection with TTL-compatible output and adjustable sensitivity thresholds via an external resistor.
• Patent-pending isolation between receiver and transmitter channels to minimize crosstalk.

Applications

• Backplane management
• Active cable transceivers
• SONET/SDH data and clock applications
• 4X Fibre Channel applications

Procurement Notes

Verify the specific ordering suffix 'MG' corresponds to the 24-pin QFN package with NiPdAu lead finish and Pb-Free status. Confirm the component meets RoHS compliance requirements for your assembly process. Ensure the industrial temperature rating (-40°C to +85°C) aligns with your system's environmental specifications before finalizing procurement.

Selection Notes

Select this component when a mixed-signal transceiver is required, specifically needing a CML receiver paired with a variable swing LVPECL transmitter. Consider the integrated loopback feature if system diagnostics are necessary. Evaluate the patented input termination if minimizing external components in the signal path is a priority. Compare against the SY58620L if a fully CML configuration is preferred instead.

Part Context

The SY58621LMG belongs to the Precision Edge product line originally developed by Micrel, Inc., which was subsequently acquired by Microchip Technology. This series focuses on low-jitter, high-speed solutions for telecom and enterprise server environments. The device represents a specialized interface solution bridging different logic families within high-speed digital systems.

Replacement Considerations

The SY58620L is documented as a related product offering a fully CML receiver and transmitter configuration. Verify pinout compatibility and electrical characteristics before substitution.

FAQ

How does the LOS function operate?

The Loss-of-Signal (LOS) circuitry monitors the receiver input amplitude. When the signal falls below a threshold set by the LOSLVL pin, the LOS output asserts HIGH. Connecting /RXEN to the LOS output maintains receiver stability during signal loss.

What is the purpose of the TXVCTRL pin?

The TXVCTRL pin controls the output amplitude of the transmitter. Connecting it to VREF_CTRL sets maximum swing, while connecting it to VCC_TXQ sets minimum swing. A variable resistor can be used for intermediate control.

How is crosstalk minimized in this device?

The device uses patent-pending MUX isolation between channels. Additionally, layout guidelines recommend ground stripping or routing receiver and transmitter traces on separate layers with orthogonal orientations.