Skyworks Solutions Inc. SI5338C-B04443-GMR

Overview

SI5338C-B04443-GMR from Skyworks Solutions is a quad-output, I²C-programmable clock generator implementing MultiSynth™ frequency synthesis with 0 ppm precision per output. It delivers four independently configurable differential or single-ended clocks (LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL) across 0.16–710 MHz, supports PCIe Gen 1–4 common clock and SRNS compliance, and achieves 0.7 ps RMS phase jitter (typ). It replaces up to four crystal oscillators in FPGA, processor, and Ethernet switch timing applications.

For engineers reviewing the SI5338C-B04443-GMR datasheet, SI5338C-B04443-GMR pinout, SI5338C-B04443-GMR application, or SI5338C-B04443-GMR equivalent, key selection criteria include its 4-output any-frequency synthesis capability, independent output voltage control (1.5/1.8/2.5/3.3 V), PCIe Gen 4 jitter compliance (0.15–0.45 ps RMS), spread-spectrum support (0.5–5.0% down-spread), and 24-QFN package compatibility with board-level thermal management requirements.

Technical Context

The SI5338C-B04443-GMR integrates a dual-stage PLL architecture: a high-stability reference PLL (loop bandwidth 1.6 MHz) followed by four independent MultiSynth™ fractional-N synthesizers. Each output stage includes programmable phase offset (<20 ps step resolution), frequency increment/decrement (1 ppm steps), and spread-spectrum modulation (33–63 kHz rate, 0.5–5.0% deviation).

It accepts flexible input references - 8–30 MHz crystal, 5–200 MHz CMOS, 5–350 MHz SSTL/HSTL, or 5–710 MHz differential - and routes them through configurable R-divider paths before the PLL. Output drivers support independent supply rails (VDDO0–VDDO3) and format selection per channel without shared resource contention.

Key Specifications

Pinout & Package

The SI5338C-B04443-GMR is housed in a 24-lead QFN package (4 mm × 4 mm, 0.5 mm pitch) with an exposed thermal pad for enhanced thermal dissipation. Pin assignments follow Skyworks' standard Si5338 top-view layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B-GM, SI5338C-B04443-GMR offers full I²C programmability and real-time frequency/phase adjustment; compared with LMK04832RHAR, it provides smaller size and lower power at the cost of absolute jitter floor, making it optimal for space-constrained, multi-protocol timing systems.

Availability

SI5338C-B04443-GMR is available at Aetrix Electronics and suitable for FPGA clocking, PCIe Gen 4 timing, and Ethernet switch applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SI5338C-B04443-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 was designed for high-density, multi-protocol timing in datacenter, networking, and broadcast systems - enabling consolidation of discrete oscillators into a single programmable IC with PCIe, Ethernet, and video-grade jitter performance.

FAQ

What is the primary function of the SI5338C-B04443-GMR?

The SI5338C-B04443-GMR is a quad-output, I²C-programmable clock generator that synthesizes four independent, low-jitter clock signals from a single reference. Its MultiSynth™ architecture enables any-frequency generation (0.16–710 MHz) with 0 ppm precision per output, supporting LVPECL, LVDS, HCSL, CMOS, SSTL, and HSTL formats. It serves as a drop-in replacement for up to four discrete oscillators in FPGA, processor, and high-speed serial interface timing systems.

Does the SI5338C-B04443-GMR support PCIe Gen 4 timing requirements?

Yes, the SI5338C-B04443-GMR meets PCIe Gen 4 common-clock jitter specifications (0.15–0.45 ps RMS, 12 kHz–20 MHz) when configured with 100 MHz HCSL outputs and a PLL loop bandwidth of 2–5 MHz. It also complies with PCIe Gen 3 SRNS (0.11–0.32 ps RMS) and has been validated using the Skyworks PCIe Clock Jitter Tool and Intel Clock Jitter Tool v1.6.4.

How many independent supply rails does the SI5338C-B04443-GMR support for its outputs?

The SI5338C-B04443-GMR supports four independent output supply rails - VDDO0, VDDO1, VDDO2, and VDDO3 - each configurable from 1.4 V to 3.63 V. This allows mixed-voltage operation: for example, CLK0A/B can drive 1.8 V LVDS while CLK2A/B drives 3.3 V CMOS, eliminating level-shifter components in multi-interface systems.

Can the SI5338C-B04443-GMR generate spread-spectrum clocking (SSC) on individual outputs?

Yes, the SI5338C-B04443-GMR supports independent spread-spectrum clocking on any output, with user-selectable parameters: frequency range (5–350 MHz), spread magnitude (0.5–5.0%), and modulation rate (33–63 kHz). SSC configuration is performed per-output via I²C register writes and does not affect other channels' frequency or phase stability.

What is the minimum and maximum input reference frequency supported by the SI5338C-B04443-GMR?

The SI5338C-B04443-GMR accepts input references from multiple sources: external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), or differential (5–710 MHz). The lowest usable frequency is 5 MHz for buffered (PLL-bypass) operation; crystal mode requires ≥8 MHz. All inputs support automatic detection and R-divider scaling for optimal PLL phase detector frequency.