SI5338C-B05278-GM

Overview

The SI5338C-B05278-GM is a programmable quad clock generator utilizing MultiSynth technology to synthesize any frequency on four independent output drivers. It supports differential and single-ended formats including LVPECL, LVDS, HCSL, CMOS, SSTL, and HSTL with supply voltages of 1.5, 1.8, 2.5, or 3.3 V. The device accepts inputs from external crystals (8–30 MHz), CMOS (up to 200 MHz), SSTL/HSTL (up to 350 MHz), or differential signals (up to 710 MHz). Key electrical parameters include a core supply voltage range of 1.71–3.63 V, typical operating current of 45 mA, and phase jitter as low as 0.7 ps RMS.

Feature Summary

• MultiSynth™ Technology: Generates four independent clocks with 0 ppm precision and glitchless frequency adjustments in 1 ppm steps.
• Flexible Input/Output: Supports differential inputs up to 710 MHz and outputs ranging from 0.16 MHz to 710 MHz across multiple signal formats.
• Low Jitter Performance: Achieves typical phase jitter of 0.7 ps RMS, compliant with PCIe Gen 1/2/3/4 common clock and SRNS standards.
• Configurable Spread Spectrum: Allows independent SSC configuration on any output with spread rates from 0.5% to 5.0% and modulation rates from 33 to 63 kHz.

Applications

• PCIe Gen 1/2/3/4 Clocking
• Ethernet Switches and Routers
• Telecom Line Cards (MSAN/DSLAM/PON)
• FPGA and Processor Clocking

Procurement Notes

Verify the specific B05278 factory code against the manufacturer's ordering guide to confirm the exact pre-programmed frequency and format configuration. Ensure I2C pull-up voltages are compatible with the selected VDDI2C level, noting that register writes may be required if the bus voltage is below 2.5 V.

Selection Notes

Select this component when replacing multiple discrete oscillators with a single flexible source. Confirm that the required output frequencies fall within the MultiSynth synthesis limits (5 MHz to Fvco/8) and that the target signal formats match the available driver configurations for LVPECL, LVDS, or CMOS.

Part Context

This part belongs to the Si5338 family of I2C-programmable clock generators. The 'B' suffix indicates a factory-programmed variant with fixed output settings, while 'GM' denotes the 24-lead QFN package. It succeeds earlier pin-controlled variants by offering software-defined flexibility via the I2C interface.

Replacement Considerations

Direct functional replacements within the same package and specification envelope include other Si5338 variants such as SI5338Q-B-GMR or SI5338F-B-GMR. Verify that the substitute part number matches the required output frequencies and signal formats, as factory programming codes differ between specific SKUs.

FAQ

What is the maximum input frequency supported by the Si5338?

The device supports differential inputs up to 710 MHz, CMOS inputs up to 200 MHz, and SSTL/HSTL inputs up to 350 MHz.

Can the Si5338 perform glitchless frequency changes?

Yes, it features an independent frequency increment/decrement capability that enables glitchless frequency adjustments in 1 ppm steps.

Is the Si5338 compliant with PCIe specifications?

Yes, it is compliant with PCIe Gen 1/2/3/4 Common Clock and Gen 3 Separate Reference No Spread (SRNS) requirements.