Skyworks Solutions Inc. SI5338B-B08686-GM

Overview

SI5338B-B08686-GM from Skyworks Solutions is an I²C-programmable quad clock generator with four independently configurable differential 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 SI5338B-B08686-GM datasheet, SI5338B-B08686-GM pinout, SI5338B-B08686-GM application, or SI5338B-B08686-GM equivalent, key selection criteria include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz), independent output voltage per driver (1.5/1.8/2.5/3.3 V), spread-spectrum capability (0.5–5.0% down-spread), and I²C/SMBus programmability with ClockBuilder Pro support.

Technical Context

The SI5338B-B08686-GM integrates a two-stage PLL architecture: a high-stability integer-N PLL for reference conditioning and four independent MultiSynth™ fractional-N synthesizers per output channel. Each synthesizer supports integer or fractional mode operation with <20 ps programmable phase step resolution and 1 ppm frequency increment/decrement granularity.

It accepts flexible input references - external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), or differential (5–710 MHz) - and delivers configurable LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL outputs with independent VDDO supplies. External feedback mode enables zero-delay operation, while loss-of-lock and loss-of-signal alarms provide real-time status monitoring.

Key Specifications

Pinout & Package

SI5338B-B08686-GM uses a 24-lead QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are fixed per Si5338 family specification and validated for this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5338B-B08686-GM, Si5332A-D08686-GM offers lower jitter and higher frequency range but at increased cost and power; ICS8430I-01LG provides simpler, lower-cost buffering but lacks any-frequency synthesis, I²C control, or spread spectrum - limiting use to static, jitter-tolerant applications.

Availability

SI5338B-B08686-GM is available at Aetrix Electronics and suitable for Ethernet switch/router, PCIe Gen 1–4 host systems, and broadcast video timing applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5338B-B08686-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 leader in analog semiconductors, specializing in RF, mobile, infrastructure, and timing solutions with over 30 years of RF and precision timing expertise.

The Si5338 product line was designed for high-performance, multi-protocol clock generation in datacenter, telecom, and broadcast equipment - emphasizing low jitter, software configurability, and compact footprint.

FAQ

What is the core supply voltage range supported by the SI5338B-B08686-GM?

The SI5338B-B08686-GM supports a core supply voltage (VDD) of 1.8 V (–5% to +10%), 2.5 V (±10%), or 3.3 V (±10%). This triple-voltage compatibility allows seamless integration into diverse power architectures without level-shifting circuitry. The device maintains full functionality and specified jitter performance across all three supply options, and its excellent PSRR minimizes sensitivity to supply noise.

Does the SI5338B-B08686-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338B-B08686-GM meets PCIe Gen 4 common clock jitter specifications with ≤0.45 ps RMS (12 kHz–20 MHz) when configured per Skyworks' recommended settings. Its design includes PLL bandwidth optimization (2–4 MHz or 2–5 MHz) and CDR alignment at 10 MHz, validated using the Skyworks PCIe Clock Jitter Tool and Intel Clock Jitter Tool v1.6.4.

How many independent output frequencies can the SI5338B-B08686-GM generate simultaneously?

The SI5338B-B08686-GM can generate four independent output frequencies simultaneously - one per output channel (CLK0–CLK3). For frequencies above 350 MHz, only two unique values may be active concurrently (Fvco/4 and Fvco/6), as constrained by the internal VCO architecture. All outputs maintain 0 ppm synthesis accuracy regardless of frequency combination.

Can the SI5338B-B08686-GM operate in clock buffer (PLL bypass) mode?

Yes, the SI5338B-B08686-GM supports clock buffer mode, where the input clock passes through with minimal additive jitter (0.165 ps RMS typical, 12 kHz–20 MHz). In this mode, the PLL is disabled, propagation delay is fixed at 2.5–4 ns, and loss-of-signal detection remains functional for frequencies ≥5 MHz - enabling low-latency, deterministic timing paths.

What software tools are available to configure the SI5338B-B08686-GM?

Skyworks ClockBuilder Pro is the official GUI-based configuration tool for the SI5338B-B08686-GM. It enables full register-level setup, jitter simulation, spread-spectrum tuning, and OTP programming. Configuration files generated by ClockBuilder Pro can be exported for production programming, and the tool includes built-in validation against PCIe, Ethernet, and broadcast timing standards.