Skyworks Solutions Inc. SI5344A-B05904-GMR

Overview

SI5344A-B05904-GMR from Skyworks is a 4-input, 4-output jitter-attenuating clock multiplier with fourth-generation DSPLL™ and MultiSynth™ architecture. 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 1028 MHz across LVDS/LVPECL/LVCMOS/CML/HCSL formats - deployed in SyncE-compliant carrier Ethernet switches and OTN transponders.

For engineers reviewing the SI5344A-B05904-GMR datasheet, SI5344A-B05904-GMR pinout, SI5344A-B05904-GMR application, or SI5344A-B05904-GMR equivalent, key selection criteria include G.8262 EEC Option 1/2 compliance, digitally programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), integrated loop filter, hitless input switching, and factory-programmable NVM configuration for deterministic power-up behavior.

Technical Context

The SI5344A-B05904-GMR implements a fourth-generation DSPLL with fractional input dividers (P), high-resolution MultiSynth output dividers (N), and integer R-dividers to synthesize any output frequency from any input frequency. Its loop bandwidth is fully digital (0.1 Hz–4 kHz), enabling application-level jitter optimization without external components.

It supports three operational modes - freerun (crystal-referenced), locked (input-synchronized), and holdover (averaged historical frequency retention up to 120 s) - with automatic/manual input selection, glitchless switching across ±500 ppm input offsets, and ramped transitions for plesiochronous clocks.

Key Specifications

Pinout & Package

SI5344A-B05904-GMR uses 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-attenuating clock multiplier applications.

Compared with SI5344A-B05904-GMR, Si5344A-D-GM1 offers identical hardware but requires field programming, while LMK04832ISQE/NOPB trades lower jitter for higher integration and different interface/power architecture - making SI5344A-B05904-GMR optimal for compact, low-jitter, I²C-configurable SyncE line cards.

Availability

SI5344A-B05904-GMR is available at Aetrix Electronics and suitable for carrier Ethernet switches, OTN transponders, and broadcast video infrastructure requiring stable component supply, long-term lifecycle support, and guaranteed G.8262 compliance.

Supply support for SI5344A-B05904-GMR 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, SyncE systems, and precision timing equipment - emphasizing ultra-low jitter, integrated loop filtering, and robust holdover operation.

FAQ

What is the primary function of the SI5344A-B05904-GMR in a SyncE system?

The SI5344A-B05904-GMR serves as a jitter-attenuating clock multiplier that cleans and regenerates timing signals to meet ITU-T G.8262 EEC Option 1/2 specifications. In SyncE systems, it locks to an incoming reference (e.g., from a primary reference clock), suppresses accumulated jitter, and distributes low-jitter outputs to downstream PHYs and MACs - ensuring phase stability and wander control across the network. SI5344A-B05904-GMR achieves this using its fourth-generation DSPLL and integrated loop filter without external components.

Does the SI5344A-B05904-GMR require external loop filter components?

No, the SI5344A-B05904-GMR integrates the entire loop filter on-die, eliminating discrete resistors and capacitors. This reduces PCB area, avoids noise coupling from external passive components, and ensures consistent jitter attenuation performance across temperature and voltage variations. The loop bandwidth remains digitally programmable from 0.1 Hz to 4 kHz, and SI5344A-B05904-GMR maintains <0.1 dB peaking across all settings due to its stable digital control architecture.

How does the SI5344A-B05904-GMR handle input clock failures in telecom applications?

Upon input clock failure, SI5344A-B05904-GMR automatically enters holdover mode using up to 120 seconds of stored historical frequency data to compute an averaged holdover frequency. This minimizes phase transients and maintains output stability during outages. The holdover window size and delay are programmable, and SI5344A-B05904-GMR exits holdover glitchlessly by ramping to the new input frequency - a feature critical for carrier-grade 50 ms failover requirements in OTN and SyncE systems.

Can the SI5344A-B05904-GMR generate both LVDS and LVCMOS outputs simultaneously?

Yes, SI5344A-B05904-GMR supports independent configuration of each of its four outputs for LVDS, LVPECL, LVCMOS, CML, or HCSL signaling. Each output has dedicated supply pins (3.3 V, 2.5 V, or 1.8 V) and programmable amplitude and common-mode voltage, enabling mixed-format clock distribution on a single device. This capability allows SI5344A-B05904-GMR to drive diverse interfaces - such as FPGA banks, SERDES PHYs, and microcontrollers - without level-shifting components.

Is the SI5344A-B05904-GMR pin-compatible with other Si5344 variants?

Yes, all Si5344 devices - including SI5344A-B05904-GMR - use the same 44-QFN 7×7 mm package with identical pinout and footprint. This allows drop-in replacement across variants (e.g., Si5344A-D-GM1, Si5344B-D-GM1) when board layout accommodates the same thermal pad and decoupling scheme. However, firmware/NVM configuration differs per variant, so SI5344A-B05904-GMR retains its preprogrammed B05904 frequency plan unless reconfigured via I²C.