SIT92211AI-X

Clock Buffers, Drivers Overview

The SiT92211 is a 2.1 GHz, 10-output ultra-low jitter clock fan-out buffer designed for high-frequency clock distribution and level translation. It features two universal differential or single-ended inputs supporting up to 2.1 GHz, one crystal input (8–50 MHz), and one LVCMOS reference output. The device provides ten outputs across two banks (A and B) configurable as LVPECL, LVDS, HCSL, or Hi-Z. Additive jitter is typically 55 fs RMS. It operates with core supplies of 3.3 V or 2.5 V, output supplies of 3.3 V/2.5 V, and an LVCMOS supply of 1.8 V/2.5 V/3.3 V. The component is housed in a 48-pin, 7 mm x 7 mm QFN package.

Clock Buffers, Drivers Feature Summary

• Ultra-low additive jitter performance of 55 fs RMS typical.
• Supports three input sources: two universal clocks (up to 2.1 GHz) and one crystal oscillator (8–50 MHz).
• Ten differential outputs distributed across two independent banks (A and B) programmable to LVPECL, LVDS, or HCSL.
• Includes a glitch-free synchronized LVCMOS reference output operating at 1.8 V, 2.5 V, or 3.3 V.

Clock Buffers, Drivers Applications

• PCI Express Gen1 through Gen5 clock distribution.
• High-performance computing and data center infrastructure.
• Telecommunications base stations and 5G infrastructure.
• Test and measurement equipment requiring low phase noise.

Clock Buffers, Drivers Procurement Notes

Verify the specific ordering suffix against the manufacturer's current datasheet to confirm voltage options and package variants. Ensure that the design accounts for the required external termination resistors for LVPECL, LVDS, and HCSL modes. Confirm power supply sequencing and decoupling requirements for the multiple VCCO domains to maintain signal integrity.

Clock Buffers, Drivers Selection Notes

Select this component when distributing clocks to mixed-voltage logic families such as LVPECL, LVDS, and LVCMOS simultaneously. The dual-bank architecture allows independent configuration of output drive types. Verify that the input source matches the supported formats (differential/single-ended/crystal) and that the frequency does not exceed 2.1 GHz for full swing operation.

Clock Buffers, Drivers Part Context

The SiT92211 belongs to SiTime’s high-performance clock buffer family, specifically engineered for applications demanding minimal added jitter. It serves as a replacement for traditional discrete buffer solutions by integrating multiple output standards and input selection into a single surface-mount package, simplifying PCB layout and reducing component count.

Clock Buffers, Drivers Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult the manufacturer's official cross-reference tools or contact sales representatives for validated alternatives compatible with the 48-pin QFN form factor and electrical specifications.

Clock Buffers, Drivers FAQ

What output driver types are supported by the SiT92211?

The SiT92211 supports LVPECL, LVDS, HCSL, and High-Impedance (Hi-Z) modes for its differential output banks. The dedicated reference output supports LVCMOS levels.

Can the SiT92211 operate with a single-ended clock input?

Yes, the two universal clock inputs (CLKin0 and CLKin1) can accept single-ended signals. Additionally, the OSCIN pin can accept a single-ended clock in bypass mode.

What is the maximum frequency supported by the crystal input?

The crystal input supports crystals with frequencies ranging from 8 MHz to 50 MHz. In bypass mode, it can accept an external single-ended clock up to 250 MHz.