Skyworks Solutions Inc. SI5338C-B04382-GM

Overview

SI5338C-B04382-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 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 SI5338C-B04382-GM datasheet, SI5338C-B04382-GM pinout, SI5338C-B04382-GM application, or SI5338C-B04382-GM equivalent, key selection criteria include PCIe Gen 4 jitter compliance (0.15–0.45 ps RMS), independent output voltage per driver (1.5/1.8/2.5/3.3 V), MultiSynth™ fractional synthesis resolution (1 ppb), spread-spectrum control (0.5–5.0% spread, 33–63 kHz modulation), and loss-of-lock/loss-of-signal alarm support.

Technical Context

The SI5338C-B04382-GM implements a two-stage PLL architecture: Stage 1 uses a high-frequency VCO (Fvco) with programmable R-divider for reference input conditioning; Stage 2 employs four independent MultiSynth™ fractional-N synthesizers (M0–M3), each with P-divider output scaling and configurable output format drivers. This enables true any-frequency synthesis across all four outputs with zero ppm frequency accuracy.

Input flexibility includes external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), or differential (5–710 MHz) references. Output stage supports LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats with independent VDDO per driver and glitchless 1 ppm frequency increment/decrement via pin or I²C control.

Key Specifications

Pinout & Package

SI5338C-B04382-GM is housed in a 24-lead, 4 × 4 mm QFN package with exposed thermal pad. Pin 1 is top-left (IN1), pin numbering proceeds counterclockwise. The package supports JEDEC-standard reflow and provides low thermal resistance (θJC = 10 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B04382-GM, SI5338C-B04382-GM offers identical hardware but user-programmable NVM, enabling full runtime configuration; versus LMK04832, it delivers lower power, smaller footprint, and true independent any-frequency synthesis-but lacks dual-loop jitter attenuation.

Availability

SI5338C-B04382-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 switch timing, multi-rate Ethernet clocking, and broadcast video synchronization requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338C-B04382-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 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-where precise, flexible, and compact timing is critical.

FAQ

What is the primary function of the SI5338C-B04382-GM in a PCIe Gen 4 system?

The SI5338C-B04382-GM serves as a quad-output common clock generator delivering four independent 100 MHz HCSL clocks compliant with PCIe Gen 4 Common Clock and SRNS specifications. Its 0.15–0.45 ps RMS jitter ensures reliable link training and stable operation across root complexes, switches, and endpoints. SI5338C-B04382-GM achieves this using MultiSynth™ fractional-N synthesis and a 2–5 MHz PLL bandwidth optimized per PCI-SIG requirements.

Does the SI5338C-B04382-GM support spread-spectrum clocking, and how is it configured?

Yes, the SI5338C-B04382-GM supports fully programmable spread-spectrum clocking on any output, with adjustable spread (0.5–5.0%), modulation rate (33–63 kHz), and direction (down-spread only). Configuration is performed via I²C registers controlling the SSC modulator within each MultiSynth™ block. SI5338C-B04382-GM defaults to ~0.5% down-spread at ~31.5 kHz, and parameters can be updated dynamically without interrupting output clocks.

How does the SI5338C-B04382-GM handle loss-of-signal or loss-of-lock conditions?

The SI5338C-B04382-GM integrates dedicated hardware comparators that monitor input clock validity and PLL lock status. Upon detection, it asserts the open-drain INTR pin and updates corresponding status registers (e.g., LOL_STATUS, LOS_STATUS). Detection times are 2.6–5 µs for input loss and 5–10 ms for loss-of-lock. SI5338C-B04382-GM allows masking and interrupt routing via I²C, enabling system-level fault response without polling.

Can the SI5338C-B04382-GM generate different output voltages simultaneously, and which pins control them?

Yes, the SI5338C-B04382-GM supports independent output supply voltages: VDDO0 powers CLK0A/B, VDDO1 powers CLK1A/B, VDDO2 powers CLK2A/B, and VDDO3 powers CLK3A/B. Each accepts 1.4–3.63 V, enabling simultaneous LVDS (2.5 V), HCSL (1.8 V), and CMOS (3.3 V) outputs. SI5338C-B04382-GM requires external decoupling on each VDDO rail and permits mixed-voltage operation without level-shifting components.

What development tools are officially supported for configuring the SI5338C-B04382-GM?

Skyworks provides ClockBuilder Pro software for intuitive GUI-based configuration of SI5338C-B04382-GM output frequencies, formats, spread-spectrum, and power modes. It generates I²C initialization scripts and validates settings against device limits. SI5338C-B04382-GM also supports the PCIe Clock Jitter Tool for automated jitter measurement and compliance reporting. Both tools are freely downloadable from skyworksinc.com.