Skyworks Solutions Inc. SI5338F-B04371-GMR

Overview

SI5338F-B04371-GMR 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 in a 4 × 4 mm 24-QFN package. It replaces up to four crystal oscillators in high-speed serial interface timing applications.

For engineers reviewing the SI5338F-B04371-GMR datasheet, SI5338F-B04371-GMR pinout, SI5338F-B04371-GMR application, or SI5338F-B04371-GMR equivalent, key selection criteria include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz per output), independent output voltage control (1.5/1.8/2.5/3.3 V), flexible reference inputs (crystal, CMOS, SSTL/HSTL, differential), and PCIe/10GbE/Ethernet switch timing validation support.

Technical Context

The SI5338F-B04371-GMR implements a two-stage PLL architecture: a high-stability integer-N PLL (Stage 1) locks to one of six input references, followed by four independent MultiSynth™ fractional-N synthesizers (Stage 2) generating each output. Each output supports programmable format (LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL), voltage (1.5–3.3 V), phase offset (±45 ns, <20 ps step), and spread-spectrum modulation (0.5–5.0%, 33–63 kHz).

It features loss-of-lock and loss-of-signal alarms, glitchless frequency increment/decrement (1 ppm steps), external feedback for zero-delay mode, and I²C/SMBus-compatible configuration via OTP NVM. Core supply operates at 1.8/2.5/3.3 V with 45 mA typical current draw under full-load conditions.

Key Specifications

Pinout & Package

SI5338F-B04371-GMR is housed in a 24-lead, 4 × 4 mm QFN package with wettable flanks and an exposed thermal pad. Pin 1 is located at top-left corner (marked dot), with pins numbered counter-clockwise. The package supports reflow soldering per JEDEC J-STD-020 (peak 260 °C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5332A-D06989-GM and ICS853S01AG-01T, the SI5338F-B04371-GMR uniquely balances field-programmability, industrial temperature range, mixed-signal voltage support, and PCIe Gen 4 readiness in a compact 4 mm QFN-making it optimal for next-gen embedded computing and networking platforms requiring design flexibility without over-spec'ing.

Availability

SI5338F-B04371-GMR is available at Aetrix Electronics and suitable for Ethernet switch/router timing, PCIe Gen 1–4 clocking, and broadcast video/audio synchronization requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338F-B04371-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 semiconductors, specializing in RF, timing, and precision analog solutions for communications, automotive, and industrial markets.

The Si5338 family was designed as a programmable, low-jitter clock generator platform for high-speed serial interfaces-including PCIe, Ethernet, Fibre Channel, and broadcast video-where flexible, accurate, and reliable timing is critical to system performance.

FAQ

What is the primary function of the SI5338F-B04371-GMR in a system?

The SI5338F-B04371-GMR serves as an I²C-programmable quad clock generator that synthesizes up to four independent, any-frequency output clocks from a single reference input. Its core function is to replace multiple discrete oscillators or clock sources in high-speed digital systems-such as PCIe root complexes, Ethernet switches, and FPGA-based platforms-while maintaining sub-1 ps RMS jitter and precise phase alignment across outputs.

Does the SI5338F-B04371-GMR support PCIe Gen 4 timing requirements?

Yes, the SI5338F-B04371-GMR meets PCIe Gen 4 common clock jitter specifications with ≤0.45 ps RMS (10 kHz–50 MHz) and has been validated using the Skyworks PCIe Clock Jitter Tool and Intel Clock Jitter Tool v1.6.4. It supports both common clock and SRNS modes, and its MultiSynth™ architecture ensures stable 100 MHz reference delivery with guaranteed compliance across –40 to +85 °C.

Can the SI5338F-B04371-GMR generate different output voltages simultaneously?

Yes, the SI5338F-B04371-GMR provides independent VDDO0–VDDO3 supplies, allowing each of its four output banks to be configured for 1.5 V, 1.8 V, 2.5 V, or 3.3 V. This enables simultaneous generation of LVDS (2.5 V), HCSL (1.8 V), and CMOS (3.3 V) signals on separate outputs-supporting heterogeneous interface requirements without level-shifting components.

How is the SI5338F-B04371-GMR programmed and configured?

The SI5338F-B04371-GMR is configured via its I²C/SMBus-compatible serial interface using Skyworks' ClockBuilder Pro software, which generates custom configuration files and supports real-time register editing. Configuration is stored in on-chip OTP NVM, enabling autonomous startup. Pin-strapped modes and hardware reset options also support factory-programmed boot behavior without host intervention.

What package type and thermal characteristics does the SI5338F-B04371-GMR have?

The SI5338F-B04371-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, supporting reliable operation at full load across –40 to +85 °C. The package complies with JEDEC J-STD-020 reflow profiles, including peak temperature up to 260 °C.