Skyworks Solutions Inc. SI5338B-B09321-GMR

Overview

SI5338B-B09321-GMR from Skyworks Solutions is an I²C-programmable quad clock generator with four independent differential output drivers, 0.7 ps RMS typical phase jitter, PCIe Gen 1–4 Common Clock and Gen 3 SRNS compliance, and support for LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL output formats across 0.16–710 MHz. 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 SI5338B-B09321-GMR datasheet, SI5338B-B09321-GMR pinout, SI5338B-B09321-GMR application, or SI5338B-B09321-GMR equivalent, this page delivers verified specifications, validated pin functions, confirmed PCIe Gen 4 jitter compliance, and two field-tested alternative parts with documented functional trade-offs.

Technical Context

The SI5338B-B09321-GMR implements a dual-stage PLL architecture: a high-stability reference stage (input frequency range 5–710 MHz) followed by four independent MultiSynth™ fractional-N synthesis blocks, each feeding a configurable output driver. This enables true any-frequency synthesis with zero ppm accuracy on all outputs without requiring external loop filters.

Each output supports independent voltage selection (1.5/1.8/2.5/3.3 V), format selection (LVPECL, LVDS, HCSL, CMOS, SSTL, HSTL), and programmable features including glitchless ±1 ppm frequency increment/decrement, <20 ps phase step resolution, and spread-spectrum modulation (0.5–5.0% spread, 33–63 kHz rate).

Key Specifications

Pinout & Package

SI5338B-B09321-GMR is housed in a 24-lead QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are fixed per Skyworks Si5338 family layout and validated for signal integrity in high-frequency clock distribution.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5338B-B09321-GMR, the Si5338A-B09321-GM offers identical hardware functionality but ships with factory-loaded settings, while the ICS8430I-01T trades programmability for lower unit cost and simpler validation-making it viable only in fixed-rate deployments.

Availability

SI5338B-B09321-GMR is available at Aetrix Electronics and suitable for PCIe Gen 4 server platforms, 10 GbE switching infrastructure, and FPGA-based industrial controllers requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SI5338B-B09321-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 communications, aerospace, and industrial markets.

The Si5338 product line delivers programmable, low-jitter clock generation for high-speed serial interfaces-including PCIe, Ethernet, and broadcast video-enabling flexible, space-constrained timing architectures.

FAQ

What is the maximum output frequency supported by SI5338B-B09321-GMR?

The SI5338B-B09321-GMR supports up to 710 MHz on LVPECL/LVDS/CML outputs, 350 MHz on SSTL/HSTL, 250 MHz on HCSL, and 200 MHz on CMOS outputs. Frequencies above 350 MHz are limited to two unique values simultaneously (Fvco/4 and Fvco/6) due to VCO constraints within the MultiSynth™ architecture.

Does SI5338B-B09321-GMR support PCIe Gen 4 Common Clock compliance?

Yes, SI5338B-B09321-GMR is explicitly validated for PCIe Gen 4 Common Clock mode with 0.15–0.45 ps RMS jitter (10 kHz–50 MHz), meeting the PCI-SIG Base Specification 4.0 rev 0.5 requirements. Measurement uses 100 MHz HCSL outputs and Intel Clock Jitter Tool v1.6.4.

Can SI5338B-B09321-GMR generate different output voltages on separate channels?

Yes, SI5338B-B09321-GMR provides four independent VDDOx supply rails (VDDO0–VDDO3), each configurable from 1.4 V to 3.63 V. This allows simultaneous LVPECL (2.5 V), LVDS (1.8 V), HCSL (1.8 V), and CMOS (3.3 V) outputs without level-shifting components.

How is SI5338B-B09321-GMR programmed, and what tools are required?

SI5338B-B09321-GMR is programmed via its I²C/SMBus interface using Skyworks' ClockBuilder Pro software. The tool generates configuration files, validates jitter performance, and exports register maps for integration into boot firmware or runtime reconfiguration sequences.

What is the thermal performance of SI5338B-B09321-GMR under full load?

Under full-load conditions (100 MHz on all outputs, 25 MHz reference), SI5338B-B09321-GMR draws 45 mA typical core current. Its 37 °C/W junction-to-ambient thermal resistance ensures safe operation up to +85 °C ambient when mounted on a standard 4-layer PCB with adequate copper pour under the exposed thermal pad.