Skyworks Solutions Inc. SI5338Q-B05389-GM

Overview

SI5338Q-B05389-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 in a 4 × 4 mm 24-QFN package. It replaces up to four crystal oscillators in Ethernet switch/router, PCIe, and FPGA clocking systems.

For engineers reviewing the SI5338Q-B05389-GM datasheet, SI5338Q-B05389-GM pinout, SI5338Q-B05389-GM application, or SI5338Q-B05389-GM equivalent, key selection criteria include output format flexibility (LVPECL/LVDS/HCSL/CMOS/SSTL), independent per-output voltage (1.5–3.3 V), any-frequency synthesis (0.16–710 MHz), spread-spectrum control (0.5–5.0% at 33–63 kHz), and glitchless frequency adjustment in 1 ppm steps.

Technical Context

The SI5338Q-B05389-GM implements a two-stage PLL architecture: a high-stability reference stage followed by four independent MultiSynth™ fractional-N synthesis blocks, each driving one output pair (CLKxA/CLKxB). Each MultiSynth supports integer or fractional mode, enabling true zero-ppm accuracy and programmable initial phase offset (±45 ns) with <20 ps step resolution.

Input support includes external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), and differential (5–710 MHz); output drivers are fully decoupled-each configurable for signal format, termination voltage (VDDOx = 1.5/1.8/2.5/3.3 V), and spread-spectrum modulation. Loss-of-lock and loss-of-signal alarms provide real-time status monitoring via INTR pin.

Key Specifications

Pinout & Package

SI5338Q-B05389-GM uses a 24-lead QFN package (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments follow standard Si5338 top-view layout: IN1/IN2 (differential ref 1), IN3/IN4 (single-ended ref), IN5/IN6 (differential ref 2), CLK0A/CLK0B through CLK3A/CLK3B (four differential output pairs), VDD (core supply), VDDO0–VDDO3 (independent output buffer supplies), SCL/SDA (I²C interface), INTR (interrupt output), and RSVD_GND (reserved ground).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B05389-GM, SI5338Q-B05389-GM offers identical performance but requires first-time programming; versus LMK04832ISQE/NOPB, it delivers superior integration (4 independent outputs, per-VDDO, SSC) at lower power and smaller size, though with slightly higher jitter floor.

Availability

SI5338Q-B05389-GM is available at Aetrix Electronics and suitable for Ethernet switch/router, PCIe Gen 1–4 host platforms, and FPGA-based embedded vision systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338Q-B05389-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 for infrastructure, automotive, and mobile markets.

The Si5338 product line was designed for high-flexibility, low-jitter clock generation in multi-protocol systems - enabling consolidation of discrete oscillators and buffers into a single programmable IC for datacenter, telecom, and broadcast equipment.

FAQ

What is the default configuration state of the SI5338Q-B05389-GM at power-up?

The SI5338Q-B05389-GM ships with blank one-time-programmable (OTP) memory and requires initial configuration via I²C using ClockBuilder Pro software. Unlike factory-programmed variants (e.g., Si5338A-B05389-GM), it does not output valid clocks until programmed. The SI5338Q-B05389-GM supports full register-level customization including input selection, MultiSynth dividers, output formats, and spread-spectrum parameters.

Does the SI5338Q-B05389-GM support PCIe Gen 4 Common Clock compliance?

Yes, the SI5338Q-B05389-GM meets PCIe Gen 4 Common Clock jitter specifications with 0.15–0.45 ps RMS (1.5 MHz–50 MHz band) when configured per Skyworks AN562 guidelines. This compliance is verified using the Skyworks PCIe Clock Jitter Tool and Intel Clock Jitter Tool v1.6.4, with all outputs set to 100 MHz HCSL format and PLL bandwidth tuned to 2–5 MHz.

Can the SI5338Q-B05389-GM generate three different frequencies above 350 MHz simultaneously?

No. The SI5338Q-B05389-GM can output only two unique frequencies above 350 MHz at once - specifically Fvco/4 and Fvco/6 - due to VCO frequency constraints and synthesis stage limitations. For example, simultaneous 400 MHz, 500 MHz, and 600 MHz outputs are not supported; users must select ≤2 high-frequency outputs and assign remaining clocks to ≤350 MHz ranges.

How is spread-spectrum modulation configured on the SI5338Q-B05389-GM?

Spread-spectrum modulation on the SI5338Q-B05389-GM is configured per-output via I²C registers controlling deviation (0.5–5.0%), modulation rate (33–63 kHz), and direction (down-spread only). Default settings are 0.5% down-spread at ~31.5 kHz. Configuration requires ClockBuilder Pro or direct register writes; no external components are needed as modulation is generated internally by the MultiSynth block.

What thermal management considerations apply to the SI5338Q-B05389-GM in continuous operation?

The SI5338Q-B05389-GM has a junction-to-ambient thermal resistance (θJA) of 37 °C/W in still air. At maximum core current (60 mA @ 3.3 V) and worst-case ambient (85 °C), junction temperature reaches ~105 °C - within the 150 °C absolute max. Recommended PCB design includes a 4 × 4 mm thermal pad connected to ≥2 internal ground planes and ≥6 vias to minimize θJA below 30 °C/W for sustained high-frequency operation.