Skyworks Solutions Inc. SI5344C-A-GM

Overview

SI5344C-A-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 integer-only frequency synthesis up to 1028 MHz (differential), operates across –40 to +85 °C, and powers up with factory-programmed configuration via on-chip NVM - deployed in 10/40/100G networking line cards and ITU-T G.8262 SyncE systems.

For engineers reviewing the SI5344C-A-GM datasheet, SI5344C-A-GM pinout, SI5344C-A-GM application, or SI5344C-A-GM equivalent, key selection criteria include its integer-only synthesis mode, 44-QFN 7×7 mm package, programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), G.8262 EEC Option 1/2 compliance, and support for LVDS/LVPECL/LVCMOS/CML/HCSL output formats with independent supply pins.

Technical Context

The SI5344C-A-GM implements a digitally controlled DSPLL architecture with fully integrated loop filter, enabling jitter attenuation without external components. Its fractional input dividers (P) and integer-only MultiSynth output dividers (N) allow hitless switching between fractionally related inputs while maintaining phase coherence.

It supports three operational modes - freerun (crystal-referenced), locked (input-synchronized), and holdover (averaged historical frequency retention up to 120 s) - with programmable fastlock bandwidth (100 Hz–4 kHz) for accelerated lock acquisition and ramped holdover exit to minimize phase transients.

Key Specifications

Pinout & Package

SI5344C-A-GM uses a 44-pin QFN package (7 mm × 7 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated 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-D-GM, SI5344C-A-GM trades fractional flexibility for cleaner spectral purity and reduced EMI filtering complexity; versus LMK5B12204, it delivers superior jitter performance, integrated NVM boot reliability, and full G.8262 compliance - making it the definitive choice for carrier Ethernet and OTN timing.

Availability

SI5344C-A-GM is available at Aetrix Electronics and suitable for 10/40/100G networking line cards, ITU-T G.8262 Synchronous Ethernet systems, and broadcast video infrastructure requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for SI5344C-A-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, with leadership in RF, timing, and precision analog ICs.

The Si5344 family is designed specifically for high-performance jitter attenuation and any-frequency clock generation in carrier-grade communications infrastructure - emphasizing G.8262 compliance, holdover resilience, and field-programmable flexibility.

FAQ

What is the primary function of the SI5344C-A-GM in a timing architecture?

The SI5344C-A-GM serves as a jitter attenuator and clock multiplier, synchronizing to noisy or unstable input references and generating ultra-low-jitter (90 fs rms) output clocks. It uses DSPLL™ technology to suppress input jitter while supporting integer-only synthesis up to 1028 MHz. In systems like 100G line cards, SI5344C-A-GM ensures timing integrity across SerDes lanes, meeting ITU-T G.8262 EEC Option 1/2 requirements without external loop filters.

Does the SI5344C-A-GM support fractional-N synthesis?

No, the SI5344C-A-GM is explicitly an integer-only device, as indicated by the "C" suffix in its ordering code per Skyworks' Si5344 Rev D Ordering Guide. It uses integer MultiSynth dividers (N) only - eliminating fractional spurs and simplifying phase noise design. This makes SI5344C-A-GM ideal for SyncE and OTN applications where spectral purity and EEC mask compliance are prioritized over arbitrary frequency ratios.

How does the SI5344C-A-GM handle input clock failures?

Upon input failure, the SI5344C-A-GM automatically enters holdover mode using averaged historical frequency data stored over up to 120 seconds. It calculates a final holdover frequency from a programmable window within that history, minimizing phase disturbance. The SI5344C-A-GM then ramps output frequency to this value - ensuring glitchless, phase-continuous operation until a valid input returns, which triggers re-lock with fastlock-assisted acquisition.

What package and thermal characteristics does the SI5344C-A-GM have?

The SI5344C-A-GM uses a 44-pin QFN package measuring 7 mm × 7 mm with 0.5 mm pitch and an exposed thermal pad. Its specified operating temperature range is –40 °C to +85 °C. Thermal resistance (θ_JA) is 36 °C/W per Skyworks' package documentation, and the exposed pad must be soldered to a thermal land for reliable power dissipation in sustained 4-output operation.

Can the SI5344C-A-GM generate LVCMOS and differential outputs simultaneously?

Yes, the SI5344C-A-GM supports simultaneous LVCMOS and differential (LVDS/LVPECL/CML/HCSL) outputs. Each of its four outputs is independently configurable for signal format, amplitude, common-mode voltage (for differential), and impedance (for LVCMOS). This allows mixed-interface designs - for example, driving a 3.3 V LVCMOS FPGA clock input and a 100 Ω LVDS SerDes reference on the same device - without external level-shifting circuitry.