Skyworks Solutions Inc. SI5344A-B05359-GMR

Overview

SI5344A-B05359-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 input frequencies up to 750 MHz and differential outputs up to 1028 MHz, and operates across –40 to +85 °C for carrier-grade SyncE line cards requiring deterministic phase alignment and holdover stability.

For engineers reviewing the SI5344A-B05359-GMR datasheet, SI5344A-B05359-GMR pinout, SI5344A-B05359-GMR application, or SI5344A-B05359-GMR equivalent, key selection criteria include G.8262 EEC Option 1/2 compliance, programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), hitless/ramped input switching, DCO mode with 0.001 ppb step size, and support for LVDS/LVPECL/LVCMOS/CML/HCSL output formats with independent supply pins.

Technical Context

The SI5344A-B05359-GMR implements a digitally controlled DSPLL with fully integrated loop filter and programmable loop bandwidth (0.1 Hz–4 kHz), enabling precise jitter filtering without external components. Its MultiSynth dividers support both integer and fractional synthesis, allowing any-output-frequency generation from any-input-frequency while maintaining sub-100-fs jitter performance.

It features four configurable clock inputs (IN0–IN3), automatic/manual hitless input switching, status monitoring (LOS/OOF/LOL), and zero-delay mode with FB_IN on IN3. The device uses in-circuit programmable OTP NVM and supports I²C/SPI control with ClockBuilder Pro™ configuration software.

Key Specifications

Pinout & Package

SI5344A-B05359-GMR is housed in a 44-pin QFN package (7 × 7 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments follow Skyworks' standardized Si5344 pinout for signal integrity and thermal management in high-density timing designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5344A-B05359-GMR, Si5344A-D-GM1 offers identical timing performance but lacks field-programmability, while LMK04832RHAR provides greater output count and dual-loop robustness at the cost of higher BOM complexity and no integrated crystal interface.

Availability

SI5344A-B05359-GMR is available at Aetrix Electronics and suitable for OTN muxponders, SyncE line cards, broadcast video infrastructure, and test equipment requiring stable component supply, long-term lifecycle support, and guaranteed G.8262 compliance.

Supply support for SI5344A-B05359-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 is part of Skyworks' Any-Frequency Timing portfolio, engineered specifically for carrier-class jitter attenuation and clock multiplication in SyncE, OTN, and broadcast infrastructure where ultra-low jitter and holdover stability are non-negotiable.

FAQ

What is the primary function of the SI5344A-B05359-GMR in a timing system?

The SI5344A-B05359-GMR functions as a jitter-attenuating clock multiplier that cleans and regenerates high-frequency clock signals using a fourth-generation DSPLL™ architecture. It accepts up to four input clocks, selects among them with hitless or ramped switching, and generates four low-jitter output clocks - all programmable to arbitrary frequencies. Its 90 fs rms jitter and G.8262 EEC Option 1/2 compliance make it ideal for SyncE and OTN applications where phase integrity is critical. SI5344A-B05359-GMR achieves this with integrated loop filtering and in-circuit programmable NVM.

Does the SI5344A-B05359-GMR support both integer and fractional frequency synthesis?

Yes, the SI5344A-B05359-GMR supports both integer and fractional synthesis modes via its MultiSynth™ engine. This allows generation of exact output frequencies - such as 74.25 MHz for SMPTE 292/425 or 156.25 MHz for Ethernet - from any input frequency, including non-integer-related sources. The fractional capability is confirmed in Skyworks' Ordering Guide for Si5344A-D-GM1/GM2 variants and applies directly to SI5344A-B05359-GMR as a member of the same Si5344A family with full feature set enabled.

What crystal frequency range is recommended for optimal jitter performance with the SI5344A-B05359-GMR?

Skyworks recommends a 48–54 MHz fundamental-mode crystal for optimal jitter performance with the SI5344A-B05359-GMR. While the device supports 25–54 MHz crystals per datasheet specifications, the 48–54 MHz range delivers lowest integrated phase jitter due to improved VCO noise floor and reduced close-in phase noise. The device integrates load capacitance, eliminating external C_L components and simplifying PCB layout. SI5344A-B05359-GMR uses this crystal as its free-run and holdover reference, directly impacting long-term stability.

Can the SI5344A-B05359-GMR operate in holdover mode, and how long does it maintain accuracy?

Yes, the SI5344A-B05359-GMR automatically enters holdover mode upon loss of all valid input clocks. It stores up to 120 seconds of historical frequency data and calculates an averaged holdover frequency from a programmable window within that history. Accuracy during holdover depends on the external crystal: with a ±0.5 ppm 50 MHz crystal, SI5344A-B05359-GMR maintains better than ±1 ppm accuracy for >24 hours. The holdover exit can be ramped to avoid phase transients - a feature confirmed in the Functional Description section of the Rev D datasheet.

Is the SI5344A-B05359-GMR pin-compatible with other Si5344 variants like Si5344A-D-GM1?

Yes, the SI5344A-B05359-GMR is pin-compatible with all Si5344A-D-xM1/M2 variants in the 44-QFN 7×7 mm package, including Si5344A-D-GM1. Pin assignments, power domains, and signal definitions match exactly per Skyworks' Package Outline documentation (Section 10.2). Differences lie only in factory programming: SI5344A-B05359-GMR contains a custom preprogrammed NVM image (B05359), whereas Si5344A-D-GM1 is blank and requires field programming. SI5344A-B05359-GMR retains full I²C/SPI configurability post-deployment.