Skyworks Solutions Inc. SI5338M-B04368-GM

Overview

SI5338M-B04368-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 clocking systems.

For engineers reviewing the SI5338M-B04368-GM datasheet, SI5338M-B04368-GM pinout, SI5338M-B04368-GM application, or SI5338M-B04368-GM equivalent, key selection considerations include its 24-QFN package, 4× differential output capability, 0 ppm synthesis accuracy, spread-spectrum control, and independent per-output voltage (1.5/1.8/2.5/3.3 V) configuration.

Technical Context

The SI5338M-B04368-GM implements a two-stage PLL architecture: a high-stability reference stage (with crystal or external clock input up to 710 MHz) followed by four independent MultiSynth™ fractional-N synthesizers, each driving a configurable output buffer. Its phase-locked loop bandwidth is 1.6 MHz typical, enabling fast lock (<25 ms) and robust jitter attenuation.

Each output supports independent format selection (LVPECL: 0.16–710 MHz; HCSL: 0.16–250 MHz; CMOS: 0.16–200 MHz), independent supply (VDDOx = 1.5/1.8/2.5/3.3 V), programmable phase offset (±45 ns, <20 ps step), and glitchless frequency increment/decrement (1 ppm steps). Input flexibility includes crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), and differential (5–710 MHz).

Key Specifications

Pinout & Package

SI5338M-B04368-GM uses a 24-lead QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are fixed per the Si5338 family and validated for this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5338M-B04368-GM, the Si5332A offers superior jitter and scalability but requires redesign for pinout and power; the ICS8430I provides lower cost and simpler validation but sacrifices programmability and voltage flexibility.

Availability

SI5338M-B04368-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 switch timing, Ethernet switching infrastructure, and broadcast video equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5338M-B04368-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 semiconductor company specializing in analog and mixed-signal connectivity solutions, with leadership in RF, timing, and power management ICs for communications, automotive, and industrial markets.

The Si5338 product line delivers highly configurable, low-jitter clock generation for systems demanding multi-frequency synthesis, PCIe compliance, and flexible signal formatting - designed specifically for FPGA, ASIC, and high-speed serial interface clocking.

FAQ

What is the primary function of the SI5338M-B04368-GM?

The SI5338M-B04368-GM is an I²C-programmable quad-output clock generator that synthesizes four independent, low-jitter clock signals from a single reference input. It replaces multiple discrete oscillators in systems requiring precise, configurable timing - such as PCIe Gen 4 switches, Ethernet routers, and broadcast video equipment - using Skyworks' MultiSynth™ technology for 0 ppm frequency accuracy.

Does the SI5338M-B04368-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338M-B04368-GM meets PCIe Gen 4 common clock specifications with ≤0.45 ps RMS jitter (12 kHz–20 MHz) when configured in standard mode and ≤0.32 ps RMS in SRNS-compliant mode. Its PLL bandwidth (1.6 MHz typical), low additive jitter, and HCSL output capability make it suitable for Gen 4 root complexes and endpoint timing without external cleanup.

Can the SI5338M-B04368-GM generate different output voltages on each channel?

Yes, the SI5338M-B04368-GM supports independent output supply rails (VDDO0–VDDO3), each configurable for 1.5 V, 1.8 V, 2.5 V, or 3.3 V. This allows simultaneous LVDS (2.5 V), HCSL (1.8 V), and CMOS (3.3 V) outputs without external level shifters - a key advantage over fixed-supply clock generators like the ICS8430I.

How is the SI5338M-B04368-GM programmed and configured?

The SI5338M-B04368-GM is programmed via its I²C/SMBus interface (SCL/SDA pins) using Skyworks' ClockBuilder Pro software, which generates custom configuration files and registers settings. Configuration can be stored in on-chip OTP NVM for autonomous startup, or loaded dynamically during system initialization - enabling field-upgradable timing profiles without hardware changes.

What package and thermal characteristics does the SI5338M-B04368-GM have?

The SI5338M-B04368-GM uses a 24-pin QFN package (4 mm × 4 mm, 0.5 mm pitch) with an exposed thermal pad. Its thermal resistance is θJA = 37 °C/W (still air) and θJC = 10 °C/W, supporting operation from –40 °C to +85 °C. The exposed pad must be soldered to a thermal plane for reliable performance at full load (45 mA core current typical).