Skyworks Solutions Inc. SI5338C-B05639-GMR

Overview

SI5338C-B05639-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 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 root complexes and FPGA-based networking systems.

For engineers reviewing the SI5338C-B05639-GMR datasheet, SI5338C-B05639-GMR pinout, SI5338C-B05639-GMR application, or SI5338C-B05639-GMR equivalent, key selection criteria include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz per output), independent output voltage per driver (1.5–3.3 V), spread-spectrum capability (0.5–5.0% down-spread), and 24-QFN package compatibility with space-constrained PCB layouts.

Technical Context

The SI5338C-B05639-GMR implements a two-stage PLL architecture: a high-stability input stage with programmable R-divider for reference conditioning, followed by four independent MultiSynth™ fractional-N synthesizers (M0–M3) each driving one output pair. Each synthesizer supports integer or fractional mode with <1 ppb frequency resolution and true zero-ppm accuracy on all outputs.

Its output stage provides per-driver configurability for LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats, independent VDDO supplies (1.4–3.63 V), and features including glitchless frequency increment/decrement (1 ppm steps), sub-20 ps phase adjustment, and loss-of-lock/loss-of-signal alarms. Input flexibility includes crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), and differential (5–710 MHz) references.

Key Specifications

Pinout & Package

SI5338C-B05639-GMR uses a 24-lead QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are fixed across Si5338 family variants and validated per Skyworks Rev. 1.6 datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B-GM, SI5338C-B05639-GMR offers full field reprogrammability and dynamic frequency tuning, while ICS8430I-01LG lacks synthesis flexibility and fails PCIe Gen 4 jitter compliance - making SI5338C-B05639-GMR the only choice for adaptive, high-performance serial interface timing.

Availability

SI5338C-B05639-GMR is available at Aetrix Electronics and suitable for PCIe Gen 4 server platforms, 10 GbE switching infrastructure, and broadcast video processing systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5338C-B05639-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 semiconductor company specializing in analog and mixed-signal connectivity solutions for wireless, broadband, automotive, and industrial markets.

The Si5338 product line delivers programmable, low-jitter clock generation for high-speed serial interfaces including PCIe, Ethernet, Fibre Channel, and broadcast video - designed to replace multiple fixed-frequency oscillators with a single configurable timing IC.

FAQ

What is the primary function of the SI5338C-B05639-GMR in a system design?

The SI5338C-B05639-GMR serves as an I²C-programmable quad clock generator that synthesizes four independent, low-jitter output clocks from a single reference input. Its core function is to replace up to four discrete crystal oscillators while enabling precise frequency, format, voltage, and phase control per output - critical for PCIe, Ethernet, and FPGA-based timing architectures. SI5338C-B05639-GMR achieves this using Skyworks' patented MultiSynth™ technology and a two-stage PLL architecture.

Does the SI5338C-B05639-GMR support PCIe Gen 4 timing requirements?

Yes, the SI5338C-B05639-GMR meets PCIe Gen 4 common clock jitter specifications with ≤0.45 ps RMS (12 kHz–20 MHz) when configured per Skyworks AN562 guidelines and measured using the Intel Clock Jitter Tool. It is explicitly validated for PCIe Gen 1/2/3/4 Common Clock and Gen 3 SRNS compliance in the official datasheet Rev. 1.6. SI5338C-B05639-GMR achieves this via optimized PLL loop bandwidth (2–5 MHz), low-noise VCO design, and differential output formatting.

Can the SI5338C-B05639-GMR generate different output voltages simultaneously?

Yes, the SI5338C-B05639-GMR supports independent output supply voltages per driver via dedicated VDDO0–VDDO3 pins, allowing simultaneous 1.8 V LVDS, 2.5 V HCSL, and 3.3 V CMOS outputs. Each VDDO pin accepts 1.4–3.63 V, enabling direct interfacing with mixed-voltage ASICs, FPGAs, and PHYs without level-shifting components. This capability is confirmed in Table 1 and Section 3.4 of the SI5338C-B05639-GMR datasheet Rev. 1.6.

How is the SI5338C-B05639-GMR programmed and configured?

The SI5338C-B05639-GMR is programmed via its I²C/SMBus-compatible serial interface (SCL/SDA pins) using Skyworks' ClockBuilder Pro software, which generates register configuration files and supports real-time tuning. Configuration includes output frequency, format, voltage, phase offset, spread spectrum, and alarm thresholds. SI5338C-B05639-GMR also supports hardware pin control for frequency/phase increment/decrement and loss-of-signal monitoring via INTR.

What package type and thermal characteristics does the SI5338C-B05639-GMR use?

The SI5338C-B05639-GMR uses a 24-lead QFN package measuring 4 mm × 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, enabling reliable operation at full load within the –40 to +85 °C ambient range. The package is documented in Section 9 ("Package Outline: 24-Lead QFN") and Table 4 ("Thermal Characteristics") of the SI5338C-B05639-GMR datasheet Rev. 1.6.