SI5338B-B03799-GM

Overview

The SI5338B-B03799-GM is a programmable quad clock generator utilizing MultiSynth technology. It synthesizes four independent clocks with zero ppm accuracy, supporting frequencies up to 350 MHz on all outputs. The device features low phase jitter of 0.7 ps RMS typical and accepts flexible inputs including differential (up to 710 MHz), single-ended CMOS, and crystal references. It operates from a single core supply of 1.8 V, 2.5 V, or 3.3 V with a typical current of 45 mA. Outputs are configurable for LVPECL, LVDS, HCSL, CMOS, SSTL, or HSTL formats via I2C control.

Feature Summary

• MultiSynth technology enables independent any-frequency synthesis on four output drivers with true zero ppm precision.
• Low phase jitter performance of 0.7 ps RMS typical across LVPECL, LVDS, HCSL, and CML formats.
• Flexible input support for external crystals (8–30 MHz), CMOS (5–200 MHz), and differential signals (5–710 MHz).
• Configurable spread spectrum generation with frequency deviation from 0.5% to 5.0% and modulation rates from 33 to 63 kHz.

Applications

• PCIe Gen 1/2/3/4 common clock and SRNS compliant timing
• Ethernet switch and router clocking
• Processor and FPGA clock distribution
• Broadcast video and audio timing systems

Procurement Notes

Verify the specific factory programming code B03799 against the target design requirements using Skyworks ClockBuilder Pro software. Confirm that the QFN-24 package land pattern matches the recommended PCB layout in the datasheet. Ensure the I2C pull-up voltage aligns with the supported range of 1.71 V to 3.63 V for proper communication.

Selection Notes

Select this model when four independent clock outputs are required with frequencies capped at 350 MHz. Choose variants with higher suffix codes if frequencies above 350 MHz are needed. Verify that the required output voltage levels (1.5 V, 1.8 V, 2.5 V, or 3.3 V) match the load specifications. Ensure the application supports I2C configuration or utilizes the internal NVM for standalone operation.

Part Context

This component belongs to the Si5338 family of I2C-programmable clock generators. The 'B' designation indicates a maximum output frequency limit of 350 MHz, distinguishing it from 'A' series parts which support up to 710 MHz. The 'GM' suffix denotes the 24-lead QFN package and lead-free composition. The B03799 code represents a specific factory-programmed configuration stored in non-volatile memory.

Replacement Considerations

Direct pin-compatible replacements within the same package include other Si5338 variants such as SI5338A-Bxxxxx-GM for higher frequency needs. Ensure the replacement part supports the required output formats and jitter specifications. Verify that the new part's factory programming code matches the desired frequency plan or reprogram using ClockBuilder Pro.

FAQ

What is the maximum output frequency for the SI5338B series?

The SI5338B series supports a maximum output frequency of 350 MHz on all four outputs.

Can the SI5338B generate spread spectrum clocks?

Yes, the device supports highly configurable spread spectrum on any output, allowing frequency deviations from 0.5% to 5.0% and modulation rates from 33 to 63 kHz.

How is the device configured?

The Si5338B is programmed via an I2C/SMBus-compatible serial interface. It also supports operation from internal NVM for standalone functionality after initial programming.