Skyworks Solutions Inc. SI5338N-B04908-GM

Overview

SI5338N-B04908-GM from Skyworks Solutions is a quad-output, I²C-programmable clock generator with MultiSynth™ frequency synthesis, delivering four independent low-jitter clocks (0.7 ps RMS typ) across LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats, supporting PCIe Gen 1–4 and Ethernet timing in telecom line cards and FPGA-based systems.

For engineers reviewing the SI5338N-B04908-GM datasheet, SI5338N-B04908-GM pinout, SI5338N-B04908-GM application, or SI5338N-B04908-GM equivalent, key selection criteria include its 4-output flexibility, 0 ppm synthesis accuracy, PCIe Gen 4 SRNS compliance, 24-QFN package, and I²C programmability via ClockBuilder Pro software.

Technical Context

The SI5338N-B04908-GM implements a dual-stage PLL architecture: a high-stability reference PLL (fBW = 1.6 MHz) locks to an external crystal (8–30 MHz) or differential/CMOS input (5–710 MHz), feeding four independent MultiSynth™ fractional-N synthesizers. Each output stage supports format- and voltage-selectable drivers (1.5–3.3 V) with per-output phase/frequency adjustment.

It features loss-of-signal and loss-of-lock monitoring, spread-spectrum control (0.5–5.0% at 33–63 kHz), and zero-delay mode via external feedback. The device operates across –40 to +85 °C with core supply options of 1.8/2.5/3.3 V and typical core current of 45 mA at 100 MHz on all outputs.

Key Specifications

Pinout & Package

SI5338N-B04908-GM is housed in a 24-lead, 4 × 4 mm QFN package with wettable flanks and an exposed thermal pad. Pin assignments are fixed per the Si5338 family and validated in Skyworks' Rev. 1.6 datasheet (page 33).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-output programmable clock generator applications.

Compared with Si5332A-D06903-GM and ICS853S01AGI-01LFT, SI5338N-B04908-GM uniquely delivers full I²C programmability, multi-format outputs, and zero-ppm synthesis across all four channels-making it optimal for complex, multi-protocol systems requiring field-upgradable timing.

Availability

SI5338N-B04908-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 switch fabrics, 10GbE line cards, and FPGA-based broadcast video routers requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SI5338N-B04908-GM includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Skyworks Solutions is a global leader in analog semiconductors, specializing in RF, timing, and precision analog solutions for infrastructure, automotive, and mobile markets.

The Si5338 product line was designed to replace multiple discrete oscillators and clock buffers in high-performance computing, networking, and telecom equipment with a single, software-configurable, low-jitter timing IC.

FAQ

What is the primary function of the SI5338N-B04908-GM?

The SI5338N-B04908-GM is a quad-output, I²C-programmable clock generator that synthesizes four independent, low-jitter clock signals from a single reference. It uses Skyworks' MultiSynth™ technology to achieve 0 ppm frequency accuracy across output frequencies ranging from 0.16 to 710 MHz in LVPECL, LVDS, HCSL, CMOS, SSTL, or HSTL formats - making SI5338N-B04908-GM ideal for PCIe, Ethernet, and FPGA timing applications.

Does the SI5338N-B04908-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338N-B04908-GM meets PCIe Gen 4 common clock and Separate Reference No Spread (SRNS) specifications, delivering ≤0.32 ps RMS jitter (typical 0.11 ps) under defined test conditions (2–5 MHz PLL bandwidth, CDR = 10 MHz). This compliance is verified per PCI Express Base Specification 4.0 rev. 0.5 and confirmed using the Skyworks PCIe Clock Jitter Tool - a key capability of the SI5338N-B04908-GM.

Can the SI5338N-B04908-GM generate different output voltages simultaneously?

Yes, the SI5338N-B04908-GM provides four independent VDDOx supply pins (VDDO0–VDDO3), each configurable from 1.5 V to 3.3 V. This allows simultaneous generation of, for example, 1.8 V LVDS clocks for an FPGA and 3.3 V CMOS clocks for a microcontroller - all from a single SI5338N-B04908-GM device - eliminating level-shifting components and simplifying power domain design.

How is the SI5338N-B04908-GM programmed and configured?

The SI5338N-B04908-GM is programmed via its I²C/SMBus-compatible serial interface (SCL/SDA pins) using Skyworks' ClockBuilder Pro software. This GUI tool enables full register configuration, frequency synthesis setup, output format/voltage selection, spread-spectrum parameters, and phase offsets - then generates custom configuration files for one-time OTP programming or runtime I²C writes. No external hardware programmer is required for SI5338N-B04908-GM deployment.

What package type and thermal characteristics does the SI5338N-B04908-GM use?

The SI5338N-B04908-GM uses a 24-pin QFN package measuring 4 × 4 mm with 0.5 mm pitch and an exposed thermal pad. Its thermal resistance is θJA = 37 °C/W (still air) and θJC = 10 °C/W, enabling reliable operation up to +85 °C ambient when properly mounted on a PCB with adequate copper pour and thermal vias - a validated mechanical and thermal profile for the SI5338N-B04908-GM in industrial and telecom environments.