Skyworks Solutions Inc. SI5338C-B11301-GM

Overview

SI5338C-B11301-GM from Skyworks Solutions is an I²C-programmable quad clock generator IC with four independent differential or single-ended output drivers, 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, processor/FPGA clocking, and broadcast video timing systems.

For engineers reviewing the SI5338C-B11301-GM datasheet, SI5338C-B11301-GM pinout, SI5338C-B11301-GM application, or SI5338C-B11301-GM equivalent, key selection considerations include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz per output), independent output voltage control (1.5/1.8/2.5/3.3 V), flexible input reference support (8–30 MHz crystal or 5–710 MHz differential), and glitchless 1 ppm frequency increment/decrement capability.

Technical Context

The SI5338C-B11301-GM implements a two-stage PLL architecture: a high-stability integer-N PLL for reference conditioning followed by four independent MultiSynth™ fractional-N synthesis blocks, each driving one output channel. This enables true zero-ppm frequency accuracy on all outputs without shared dividers or frequency coupling.

Each output driver supports configurable signal formats (LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL), independent supply voltage (VDDOx), programmable initial phase offset (±45 ns), and fine-grained phase adjustment (<20 ps steps). The device also integrates loss-of-lock and loss-of-signal alarms, spread-spectrum control (0.5–5.0% spread, 33–63 kHz modulation), and external feedback mode for zero-delay operation.

Key Specifications

Pinout & Package

SI5338C-B11301-GM uses a 24-lead QFN package (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per Skyworks Rev. 1.6 datasheet, page 33.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B11301-GM, the SI5338C-B11301-GM trades ±10 ppm initial accuracy for broader qualification across industrial temperature and lower unit cost, while retaining full MultiSynth™ configurability; versus ICS8430I-01, it adds full frequency/phase/format flexibility at the cost of higher design complexity and software dependency.

Availability

SI5338C-B11301-GM is available at Aetrix Electronics and suitable for Ethernet switch/router, PCIe Gen 1–4 systems, and broadcast video timing applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5338C-B11301-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 family is designed as a highly configurable, low-jitter clock generator platform targeting high-speed digital systems requiring multiple precision clocks from a single compact IC-specifically addressing PCIe, Ethernet, and broadcast video timing challenges.

FAQ

What is the primary function of the SI5338C-B11301-GM?

The SI5338C-B11301-GM is an I²C-programmable quad clock generator IC that synthesizes four independent, low-jitter output clocks from a single input reference. Its core function is to replace multiple discrete oscillators in high-speed digital systems while enabling precise frequency, phase, format, and voltage configuration per output channel. The SI5338C-B11301-GM achieves this using Skyworks' patented MultiSynth™ technology and supports PCIe Gen 1–4, Ethernet, and broadcast video timing standards.

Does the SI5338C-B11301-GM support spread-spectrum clocking (SSC)?

Yes, the SI5338C-B11301-GM supports fully programmable spread-spectrum clocking on any output. It allows selection of spread percentage from 0.5% to 5.0%, modulation rate from 33 kHz to 63 kHz, and spread direction (down-spread only). These parameters are configured independently per output via I²C registers. The SI5338C-B11301-GM's SSC capability is validated for EMI reduction in PCIe Gen 3/4 and Ethernet applications without violating jitter limits.

What input reference options does the SI5338C-B11301-GM accept?

The SI5338C-B11301-GM accepts multiple input reference types: an 8–30 MHz fundamental-mode crystal connected to IN1/IN2, or external clock signals applied to IN1/IN2 (5–710 MHz differential), IN3/IN4 (5–200 MHz CMOS), or IN5/IN6 (5–350 MHz SSTL/HSTL). All inputs support automatic loss-of-signal detection with configurable release timing. The SI5338C-B11301-GM does not require external buffering for standard crystal or LVDS inputs.

Can the SI5338C-B11301-GM generate different output voltages simultaneously?

Yes, the SI5338C-B11301-GM supports independent output supply voltages per driver bank: VDDO0, VDDO1, VDDO2, and VDDO3 each accept 1.5 V, 1.8 V, 2.5 V, or 3.3 V. This allows simultaneous generation of LVDS (2.5 V), HCSL (1.8 V), and CMOS (3.3 V) outputs from a single SI5338C-B11301-GM device, eliminating level-shifting components in mixed-voltage systems such as FPGA-based compute platforms.

Is the SI5338C-B11301-GM pin-compatible with other Si5338 variants?

Yes, all Si5338 variants-including SI5338C-B11301-GM, SI5338A-B11301-GM, and SI5338B-B11301-GM-are fully pin-compatible and share identical 24-QFN packaging, pin assignments, and register maps. Differences lie solely in factory-programmed NVM calibration data (affecting initial frequency accuracy and jitter performance), not hardware layout or firmware interface. Migration between variants requires only reprogramming or replacement without PCB changes.