Skyworks Solutions Inc. SI5338B-B09793-GMR

Overview

SI5338B-B09793-GMR from Skyworks Solutions is an I²C-programmable quad clock generator IC with four independently configurable differential or single-ended outputs, 0.7 ps RMS typical phase jitter, PCIe Gen 1–4 Common Clock and Gen 3 SRNS compliance, and operation across –40 to +85 °C. It replaces up to four crystal oscillators in Ethernet switch/router, PCIe, and FPGA clocking systems.

For engineers reviewing the SI5338B-B09793-GMR datasheet, SI5338B-B09793-GMR pinout, SI5338B-B09793-GMR application, or SI5338B-B09793-GMR equivalent, key selection criteria include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz per output), independent output voltage support (1.5/1.8/2.5/3.3 V), spread-spectrum capability (0.5–5.0% down-spread), and 24-QFN package compatibility with high-density PCB layouts.

Technical Context

The SI5338B-B09793-GMR implements a two-stage PLL architecture: a high-stability input stage with programmable R-divider and a fractional-N MultiSynth™ synthesis stage per output, enabling independent frequency generation with true zero ppm accuracy. Its I²C/SMBus interface supports dynamic reconfiguration without reset.

Each of the four output drivers supports LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats with independent supply rails (VDDO0–VDDO3), programmable phase offset (±45 ns, <20 ps step), and glitchless frequency increment/decrement (1 ppm steps). External feedback mode enables zero-delay operation.

Key Specifications

Pinout & Package

SI5338B-B09793-GMR is housed in a 24-lead, 4 × 4 mm QFN package with exposed thermal pad. Pin assignments are fixed per Skyworks' Si5338 family layout and validated for signal integrity in high-speed clock distribution.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B09793-GMR, the SI5338B-B09793-GMR offers identical hardware but optimized factory firmware for PCIe/Ethernet timing, while the LMK04832RHAT provides superior jitter cleaning at the cost of configurability, power, and footprint-making SI5338B-B09793-GMR the preferred choice for space-constrained, multi-protocol clocking.

Availability

SI5338B-B09793-GMR is available at Aetrix Electronics and suitable for Ethernet switch/router, PCIe Gen 4 platform development, and broadcast video equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5338B-B09793-GMR 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 and mixed-signal semiconductors, specializing in RF, timing, and connectivity solutions for infrastructure, automotive, and mobile markets.

The Si5338 product line delivers programmable, low-jitter clock generation for high-speed serial interfaces-including PCIe, Ethernet, and Fibre Channel-enabling flexible, software-defined timing in next-generation computing and networking platforms.

FAQ

What is the primary function of the SI5338B-B09793-GMR in a system design?

The SI5338B-B09793-GMR serves as a programmable quad clock generator that synthesizes up to four independent, precise output frequencies from a single input reference. Its role is to replace multiple fixed-frequency crystal oscillators while delivering sub-picosecond jitter performance required by PCIe Gen 3/4, 10GbE, and broadcast video systems. The SI5338B-B09793-GMR achieves this using Skyworks' patented MultiSynth™ technology and supports flexible output formats including LVDS, LVPECL, and HCSL.

Does the SI5338B-B09793-GMR support PCIe Gen 4 Common Clock compliance?

Yes, the SI5338B-B09793-GMR meets PCIe Gen 4 Common Clock jitter specifications with 0.15–0.45 ps RMS (10 kHz–50 MHz) when configured per Skyworks' recommended settings. This compliance is verified using the Skyworks PCIe Clock Jitter Tool and aligns with PCI-Express Base Specification 4.0 rev. 0.5. The SI5338B-B09793-GMR achieves this with its low-noise PLL architecture and optimized loop bandwidth settings.

Can the SI5338B-B09793-GMR generate different output voltages simultaneously?

Yes, the SI5338B-B09793-GMR supports independent output supply rails (VDDO0–VDDO3), allowing simultaneous operation at 1.5 V, 1.8 V, 2.5 V, and 3.3 V across its four output banks. This enables direct interfacing with mixed-voltage devices such as 1.8 V FPGAs, 2.5 V SerDes, and 3.3 V legacy peripherals without external level shifters. Each VDDO rail powers its corresponding CLKxA/CLKxB pair in the SI5338B-B09793-GMR.

How is the SI5338B-B09793-GMR programmed and configured?

The SI5338B-B09793-GMR is programmed via its I²C/SMBus-compatible serial interface using Skyworks' ClockBuilder Pro software. This GUI tool enables full register configuration-including input selection, MultiSynth™ dividers, output format, voltage, spread spectrum, and phase offsets-without requiring custom firmware. Configuration can be stored in on-chip OTP memory, making the SI5338B-B09793-GMR operational immediately after power-up with no host intervention.

What package type and thermal characteristics does the SI5338B-B09793-GMR have?

The SI5338B-B09793-GMR 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 at full load within the –40 to +85 °C industrial temperature range. The SI5338B-B09793-GMR's compact footprint and low thermal impedance support high-density PCB layouts in space-constrained networking and telecom modules.