Skyworks Solutions Inc. SI5344B-B04173-GM

Overview

SI5344B-B04173-GM from Skyworks is a 4-input, 4-output jitter attenuator/clock multiplier IC using fourth-generation DSPLL™ and MultiSynth™ technologies. It delivers ultra-low 90 fs rms jitter, supports differential (8 kHz–750 MHz) and LVCMOS (8 kHz–250 MHz) inputs, and generates programmable outputs from 100 Hz to 350 MHz with G.8262 SyncE compliance - deployed in carrier Ethernet switches and OTN transponders.

For engineers reviewing the SI5344B-B04173-GM datasheet, SI5344B-B04173-GM pinout, SI5344B-B04173-GM application, or SI5344B-B04173-GM equivalent, key selection considerations include its 350 MHz max output frequency limit (vs. 1028 MHz in Si5344A), integer-only synthesis mode, 44-QFN 7×7 mm package, and factory-programmed configuration for immediate deployment in SyncE-compliant line cards.

Technical Context

The SI5344B-B04173-GM implements a digitally controlled DSPLL with fully integrated loop filter and programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), enabling precise optimization of phase noise suppression in telecom timing applications. Its MultiSynth architecture uses integer-only frequency synthesis (no fractional-N dividers), supporting hitless and glitchless input switching between up to four clocks.

It operates across freerun, locked, and holdover modes with status monitoring (LOS/OOF/LOL), automatic/manual input selection, and ramped holdover exit. Core supply is 1.8 V ±5% (VDD), analog supply 3.3 V ±5% (VDDA), with independent 1.8/2.5/3.3 V output supply pins for signal integrity control.

Key Specifications

Pinout & Package

The SI5344B-B04173-GM is housed in a 44-pin QFN package (7 mm × 7 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per Skyworks Si5344 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 Si5344A-B04173-GM, SI5344B-B04173-GM trades frequency range and synthesis flexibility for improved phase noise purity in integer-only operation - making it optimal for fixed-frequency SyncE deployments. Versus LMK04832, it offers smaller footprint and lower power but lacks dual-loop architecture for ultra-deep jitter cleaning.

Availability

SI5344B-B04173-GM is available at Aetrix Electronics and suitable for carrier Ethernet switches, OTN transponders, broadcast video infrastructure, and test equipment requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for SI5344B-B04173-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, automotive, and industrial markets.

The Si5344 family is designed specifically for high-performance jitter attenuation and any-frequency clock generation in telecom infrastructure, meeting stringent ITU-T G.8262 and Telcordia GR-1244-CORE requirements.

FAQ

What is the maximum output frequency supported by the SI5344B-B04173-GM?

The SI5344B-B04173-GM supports a maximum output frequency of 350 MHz. This limit is defined by its "B" variant designation in the Si5344 ordering guide and applies across all output formats (LVDS, LVPECL, LVCMOS, etc.). It is optimized for SyncE EEC Option 2 applications such as 10G/100G Ethernet PHY clocks and OTN OTU2/OTU4 framing clocks, where frequencies above 350 MHz are not required.

Does the SI5344B-B04173-GM support fractional-N synthesis?

No, the SI5344B-B04173-GM implements integer-only frequency synthesis. This is confirmed by its part number suffix "B" (per Skyworks Ordering Guide), which denotes the 0.001–350 MHz integer-only variant. Fractional-N capability is reserved for "A" and "C" variants. Integer-only operation eliminates fractional spurs and simplifies loop filter design, enhancing spectral purity in fixed-frequency telecom timing roles.

Is the SI5344B-B04173-GM preprogrammed at the factory?

Yes, the SI5344B-B04173-GM is a factory preprogrammed device. The "B04173" segment of the part number indicates a unique configuration assigned by Skyworks and programmed into its on-chip non-volatile memory (NVM). Upon power-up, SI5344B-B04173-GM immediately delivers its designated output frequencies and settings without requiring host processor initialization or external configuration.

What crystal frequency is recommended for optimal jitter performance with the SI5344B-B04173-GM?

A 48–54 MHz fundamental-mode crystal is recommended for optimal jitter performance with the SI5344B-B04173-GM. Per Skyworks Si5344 Rev D datasheet Section 3.5, crystals in this range minimize phase noise contribution to the DSPLL's reference path. The device integrates internal load capacitors, eliminating external C_L components and reducing board-level noise coupling - critical for achieving the specified 90 fs rms jitter.

Can the SI5344B-B04173-GM operate in holdover mode, and what determines its holdover stability?

Yes, the SI5344B-B04173-GM supports holdover mode with programmable averaging of up to 120 seconds of historical lock data. Holdover stability depends entirely on the external crystal or TCXO connected to XA/XB: a standard 50 ppm crystal yields ~±50 ppm holdover drift, while a 0.1 ppm TCXO enables <±0.1 ppm drift over 24 hours - essential for SyncE pizza-box applications meeting G.8262 EEC Option 1.