Skyworks Solutions Inc. SI5345A-B03292-GM

Overview

SI5345A-B03292-GM from Skyworks is a 10-channel, any-frequency jitter attenuator and clock multiplier featuring fourth-generation DSPLL™ and MultiSynth™ architectures. It delivers ultra-low 90 fs rms jitter, supports 4 differential or LVCMOS inputs and 10 programmable outputs (LVDS/LVPECL/LVCMOS/CML/HCSL), and operates across –40 to +85 °C. It is deployed in ITU-T G.8262-compliant Synchronous Ethernet line cards requiring precise holdover stability and hitless clock switching.

For engineers reviewing the SI5345A-B03292-GM datasheet, SI5345A-B03292-GM pinout, SI5345A-B03292-GM application, or SI5345A-B03292-GM equivalent, key selection considerations include its digitally programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), factory-programmable NVM configuration, support for gapped clock locking, DCO mode with 0.001 ppb step size, and compliance with SyncE EEC Option 1/2.

Technical Context

The SI5345A-B03292-GM implements a fourth-generation DSPLL with fully integrated loop filter and fractional input dividers (P) enabling hitless switching between fractionally related input clocks. Its MultiSynth output dividers (N) support both integer and fractional synthesis, while independent R-dividers allow final output frequency tuning.

It operates in freerun, locked, holdover, and zero-delay modes, with programmable holdover averaging over up to 120 s of historical frequency data. Status monitoring includes LOS, OOF, and LOL detection, and input switching supports automatic priority-based selection, ramped transitions, and glitchless pull-in for ±500 ppm frequency offsets.

Key Specifications

Pinout & Package

The SI5345A-B03292-GM is housed in a 64-pin QFN package (9×9 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated per Skyworks Si5345 Rev D datasheet Section 9 (Pin Descriptions).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar jitter attenuator applications.

Compared with SI5345A-B03292-GM, Si5345B-D-GM sacrifices high-frequency capability for lower cost, while LMK04832RHAT trades integrated crystal simplicity for greater architectural flexibility and isolation-neither offers identical feature parity in SyncE holdover, gapped clock support, or NVM-based zero-config deployment.

Availability

SI5345A-B03292-GM is available at Aetrix Electronics and suitable for OTN muxponders, Synchronous Ethernet line cards, broadcast video infrastructure, and test equipment requiring stable component supply, guaranteed long-term availability, and factory-programmed configuration traceability.

Supply support for SI5345A-B03292-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 communications, industrial, and automotive markets.

The Si5345 family is designed specifically for high-performance timing in carrier-class networking and broadcast systems, emphasizing jitter attenuation, holdover stability, and field-programmable flexibility without external loop filters.

FAQ

What is the primary function of the SI5345A-B03292-GM in a telecom timing architecture?

The SI5345A-B03292-GM serves as a jitter-attenuating clock multiplier that cleans and regenerates timing signals from noisy or unstable network references. It locks to incoming sync sources (e.g., PTP-derived clocks or SyncE inputs), suppresses phase noise using its DSPLL, and generates multiple low-jitter outputs for SerDes, PHYs, and packet processors. Its holdover capability maintains timing integrity during input loss-making SI5345A-B03292-GM essential for ITU-T G.8262-compliant carrier infrastructure.

Does the SI5345A-B03292-GM require external loop filter components?

No, the SI5345A-B03292-GM integrates the entire DSPLL loop filter on-die. This eliminates discrete capacitors and resistors traditionally needed in PLL designs, reducing PCB area, component count, and susceptibility to board-level noise coupling. The loop bandwidth remains digitally programmable from 0.1 Hz to 4 kHz without hardware changes-ensuring SI5345A-B03292-GM delivers consistent jitter performance across temperature and voltage variations.

How does the SI5345A-B03292-GM handle input clock failures in a redundant timing system?

Upon input failure, the SI5345A-B03292-GM automatically enters holdover mode using up to 120 seconds of stored frequency history to compute an averaged holdover frequency. This minimizes phase transients and meets ITU-T G.8262 wander limits. When a valid clock returns, SI5345A-B03292-GM performs a ramped, glitchless reacquisition-linearly adjusting output frequency at user-defined rates (e.g., 0.2–40,000 ppm/s) to avoid disrupting downstream SerDes lock states.

Can the SI5345A-B03292-GM generate different output frequencies simultaneously?

Yes, the SI5345A-B03292-GM supports independent frequency generation on all 10 outputs. Each output connects via a crosspoint switch to one of multiple MultiSynth dividers, each configurable with unique integer/fractional division ratios. This allows concurrent synthesis of, for example, 156.25 MHz (10GbE), 311.04 MHz (OTN OTU4), 74.25 MHz (SMPTE video), and 10 MHz (reference)-all from a single 10 MHz or 100 MHz input, without external dividers or synthesizers.

Is factory programming required for the SI5345A-B03292-GM to operate out-of-box?

No-SI5345A-B03292-GM powers up with default configuration stored in on-chip NVM, providing functional clocks immediately. However, the B03292 suffix indicates this specific unit is factory preprogrammed by Skyworks with a custom frequency plan (e.g., defined input/output mappings, jitter BW, holdover settings). That configuration is retained across power cycles, eliminating boot-time I²C initialization and ensuring SI5345A-B03292-GM delivers known, verified timing behavior from power-on.