Skyworks Solutions Inc. SI5338C-B04398-GM

Overview

SI5338C-B04398-GM from Skyworks Solutions is an I²C-programmable quad clock generator 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 high-speed serial interface timing applications such as PCIe root complexes and FPGA clock trees.

For engineers reviewing the SI5338C-B04398-GM datasheet, SI5338C-B04398-GM pinout, SI5338C-B04398-GM application, or SI5338C-B04398-GM 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 space-constrained PCB layouts.

Technical Context

The SI5338C-B04398-GM implements a two-stage PLL architecture: a high-stability integer-N PLL (Stage 1) locks to one of six input references (crystal, CMOS, SSTL/HSTL, or differential), followed by four independent MultiSynth™ fractional-N synthesizers (Stage 2) generating precise output frequencies. Each output driver supports LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats with programmable slew rate and termination.

It features real-time frequency and phase adjustment via dedicated pins (FINC/FDEC, PINC/PDEC) enabling glitchless 1 ppm frequency steps and <20 ps phase steps, plus loss-of-lock and loss-of-signal alarms for system-level fault monitoring. The device operates from a single 1.8/2.5/3.3 V core supply with 45 mA typical current draw and integrated OTP NVM for factory or field programming.

Key Specifications

Pinout & Package

SI5338C-B04398-GM is housed in a 24-lead, 4 × 4 mm QFN package with exposed thermal pad. Pin 1 is located at top-left corner (IN1), and pin numbering proceeds counterclockwise. The package supports standard JEDEC reflow and provides low thermal resistance (θ_JA = 37 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B-GM and ICS853S01I, SI5338C-B04398-GM uniquely combines field-programmable OTP, full I²C configurability, and PCIe Gen 4–compliant jitter performance in a single 4×4 mm package-making it optimal for prototyping, multi-platform reuse, and systems requiring post-production clock tuning.

Availability

SI5338C-B04398-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 switch designs, 10 GbE networking hardware, and FPGA-based broadcast video equipment requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SI5338C-B04398-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 wireless, broadband, and industrial markets.

The Si5338 product line was designed to replace multiple discrete oscillators and clock buffers in high-speed digital systems, delivering ultra-low jitter, software-defined frequency agility, and compact integration for PCIe, Ethernet, and FPGA timing applications.

FAQ

What is the primary function of the SI5338C-B04398-GM in a timing architecture?

The SI5338C-B04398-GM serves as an I²C-programmable quad clock generator that synthesizes four independent, low-jitter output clocks from a single reference. Its MultiSynth™ technology enables precise any-frequency generation (0.16–710 MHz) with 0 ppm error, making SI5338C-B04398-GM ideal for replacing multiple crystal oscillators in PCIe, Ethernet, and FPGA clock trees while maintaining strict jitter compliance.

Does the SI5338C-B04398-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338C-B04398-GM meets PCIe Gen 4 common clock jitter specifications with ≤0.45 ps RMS (10 kHz–50 MHz) when configured per Skyworks' recommended settings-including PLL bandwidth of 2–4 MHz and CDR = 10 MHz. Measured data confirms 0.15–0.45 ps RMS performance, validating SI5338C-B04398-GM for root complex and endpoint timing in Gen 4 systems.

How many output formats does the SI5338C-B04398-GM support per channel?

The SI5338C-B04398-GM supports LVPECL, LVDS, HCSL, CML, CMOS, SSTL, and HSTL output formats across its four differential output pairs. Each channel can be independently configured for format, voltage (1.5/1.8/2.5/3.3 V), slew rate, and termination-allowing SI5338C-B04398-GM to drive mixed-logic-family loads without external level shifters or buffers.

Can the SI5338C-B04398-GM operate in clock buffer (PLL bypass) mode?

Yes, the SI5338C-B04398-GM supports clock buffer mode, where the PLL is bypassed and input clocks pass directly to outputs with minimal additive jitter (0.165 ps RMS, 12 kHz–20 MHz). This mode is enabled via register configuration and preserves SI5338C-B04398-GM's low-latency path for applications requiring deterministic propagation delay and zero PLL-induced phase noise.

What development tools are available for configuring the SI5338C-B04398-GM?

Skyworks provides ClockBuilder Pro-a free GUI-based software tool-for intuitive SI5338C-B04398-GM configuration, including frequency planning, jitter analysis, and register map generation. Users can export .c files for embedded initialization or .hex files for OTP programming. The PCIe Clock Jitter Tool is also available to validate SI5338C-B04398-GM output against Intel's PCIe jitter compliance masks.