Skyworks Solutions Inc. SI5338B-B04802-GM

Overview

SI5338B-B04802-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 from 1.8/2.5/3.3 V core supply. It replaces up to four crystal oscillators in high-speed serial interface timing applications such as PCIe switch cards and 10 GbE line cards.

For engineers reviewing the SI5338B-B04802-GM datasheet, SI5338B-B04802-GM pinout, SI5338B-B04802-GM application, or SI5338B-B04802-GM equivalent, key selection considerations include its MultiSynth™ fractional-N synthesis architecture, independent per-output voltage (1.5–3.3 V), ±20 ps phase step resolution, spread-spectrum capability (0.5–5.0% down-spread), and 24-QFN 4×4 mm package with exposed thermal pad.

Technical Context

The SI5338B-B04802-GM implements a two-stage PLL architecture: a high-stability integer-N Phase-Locked Loop (Stage 1) locks to one of six input references (crystal, CMOS, SSTL/HSTL, or differential), followed by four independent MultiSynth™ fractional-N synthesis blocks (Stage 2) generating output clocks with 1 ppb frequency resolution. Each output driver supports LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats.

It features loss-of-lock and loss-of-signal alarms, programmable initial phase offset (±45 ns), glitchless frequency increment/decrement in 1 ppm steps, and independent spread-spectrum modulation (33–63 kHz rate, 0.5–5.0% deviation) on any output. The device operates across –40 to +85 °C and supports external feedback for zero-delay mode.

Key Specifications

Pinout & Package

SI5338B-B04802-GM uses a 24-lead QFN package (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are fixed per the Si5338 family and verified in Skyworks Rev. 1.6 datasheet Figure 1 (Top View).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B04802-GM, the SI5338B-B04802-GM offers identical hardware but distinct factory NVM content; versus LMK04832, it provides finer per-output configurability and lower jitter at reduced power, though without JESD204B SYSREF support.

Availability

SI5338B-B04802-GM is available at Aetrix Electronics and suitable for PCIe switch timing, 10 GbE line card clocking, broadcast video synchronization, and FPGA-based test equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338B-B04802-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 precision analog products for infrastructure, automotive, and mobile markets.

The Si5338 product line delivers highly configurable, low-jitter clock generation for high-speed serial interfaces-including PCIe, Ethernet, Fibre Channel, and broadcast video-enabling consolidation of multiple oscillators into a single programmable IC.

FAQ

What is the primary function of the SI5338B-B04802-GM?

The SI5338B-B04802-GM is an I²C-programmable quad clock generator that synthesizes up to four independent, zero-ppm-accurate output frequencies from a single reference input. It serves as a drop-in replacement for multiple crystal oscillators in applications like PCIe switches and 10 GbE line cards, leveraging Skyworks' MultiSynth™ technology for low-jitter, flexible timing.

Does the SI5338B-B04802-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338B-B04802-GM meets PCIe Gen 4 Common Clock specifications with ≤0.45 ps RMS jitter (1.5 MHz–50 MHz band) and ≤33.6 ps pk-pk total jitter when configured per Skyworks AN562 guidelines. Its 0.7 ps RMS typical phase jitter and SRNS compliance make it suitable for Gen 3 and Gen 4 switch and endpoint timing.

How is the SI5338B-B04802-GM programmed and configured?

The SI5338B-B04802-GM is programmed via its I²C/SMBus-compatible interface using Skyworks' ClockBuilder Pro software, which generates custom configuration files and supports runtime reconfiguration. Factory-programmed NVM stores default settings, enabling immediate clock output at power-up without host intervention.

What output signal formats does the SI5338B-B04802-GM support?

The SI5338B-B04802-GM supports LVPECL, LVDS, HCSL, CML, CMOS, SSTL, and HSTL output formats across its four differential pairs (CLK0A/B–CLK3A/B). Each output bank (VDDO0–VDDO3) is independently configurable for 1.5 V, 1.8 V, 2.5 V, or 3.3 V supply, enabling direct interface to mixed-voltage SoCs and FPGAs.

What is the operating temperature range and package type of the SI5338B-B04802-GM?

The SI5338B-B04802-GM operates from –40 °C to +85 °C and is housed in a RoHS-compliant 24-pin QFN package measuring 4 × 4 mm with 0.5 mm pitch and an exposed thermal pad. This compact footprint supports high-density PCB layouts in telecom, computing, and broadcast infrastructure designs.