Skyworks Solutions Inc. SI5344B-B05370-GM

Overview

SI5344B-B05370-GM from Skyworks is a 4-input, 4-output jitter attenuator/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 outputs from 100 Hz to 350 MHz with programmable jitter attenuation bandwidth (0.1 Hz–4 kHz). It is used in SyncE-compliant carrier Ethernet switches requiring precise holdover stability and hitless clock switching.

For engineers reviewing the SI5344B-B05370-GM datasheet, SI5344B-B05370-GM pinout, SI5344B-B05370-GM application, or SI5344B-B05370-GM equivalent, key selection criteria include its 350 MHz max output frequency limit (vs. 1028 MHz in Si5344A), G.8262 EEC Option 1/2 compliance, integrated loop filter, and factory-programmed configuration for immediate deployment in OTN line cards and 10/40 GbE systems.

Technical Context

The SI5344B-B05370-GM implements a digitally controlled DSPLL with fully integrated loop filter and programmable loop bandwidth (0.1 Hz–4 kHz), enabling optimized jitter attenuation for SyncE applications. Its MultiSynth dividers support integer-only synthesis up to 350 MHz, distinguishing it from fractional-capable variants like Si5344A.

It operates across freerun, locked, and holdover modes, with automatic input switching, glitchless frequency transitions, and ramped holdover exit using programmable slew rates (0.2–40,000 ppm/s). Input qualification includes LOS/OOF detection, and status monitoring is provided via INTRb pin and register flags.

Key Specifications

Pinout & Package

SI5344B-B05370-GM uses a 44-pin QFN package (7 mm × 7 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per Skyworks 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, SI5344B-B05370-GM trades synthesis flexibility for tighter jitter specification at lower frequencies and simplified layout. Against LMK04832, it eliminates external loop components and reduces design validation effort for telecom timing applications.

Availability

SI5344B-B05370-GM is available at Aetrix Electronics and suitable for carrier Ethernet switches, OTN muxponders, broadcast video infrastructure, and test & measurement equipment requiring stable component supply, guaranteed long-term availability, and factory-programmed reliability.

Supply support for SI5344B-B05370-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 infrastructure, automotive, and industrial markets.

The Si5344 family is designed specifically for high-reliability telecom timing applications, delivering jitter attenuation, holdover stability, and seamless clock switching in SyncE, OTN, and broadcast systems.

FAQ

What is the maximum output frequency supported by SI5344B-B05370-GM?

The SI5344B-B05370-GM supports a maximum output frequency of 350 MHz. This is specified in the Skyworks Si5345/44/42 Rev D Ordering Guide for the "B" variant, which denotes integer-only synthesis up to 350 MHz-distinct from the "A" variant's 1028 MHz capability. This limit ensures optimal jitter performance and stability for SyncE EEC Option 2 applications.

Does SI5344B-B05370-GM require an external loop filter?

No, SI5344B-B05370-GM does not require an external loop filter. Its fourth-generation DSPLL features a fully integrated loop filter, eliminating discrete RC components and associated noise coupling risks. This integration simplifies PCB layout, reduces bill-of-materials cost, and improves timing robustness in high-density telecom line cards.

Is SI5344B-B05370-GM compliant with ITU-T G.8262?

Yes, SI5344B-B05370-GM meets ITU-T G.8262 EEC Option 1 and Option 2 specifications for Synchronous Ethernet equipment clocks. Its 90 fs rms jitter (12 kHz–20 MHz), programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), and holdover stability with averaged historical frequency data ensure full compliance without external wander compensation circuits.

How is SI5344B-B05370-GM configured at power-up?

SI5344B-B05370-GM powers up with a known frequency configuration stored in on-chip non-volatile memory (NVM). As a factory preprogrammed part (indicated by "B05370" in the orderable part number), it loads its validated clock tree settings-including input selection, output frequencies, formats, and loop bandwidth-immediately after initialization, eliminating boot-time configuration delays.

What input clock types does SI5344B-B05370-GM support?

SI5344B-B05370-GM supports both differential (LVDS, LVPECL, CML, HCSL) and single-ended LVCMOS input clocks. Differential inputs operate from 8 kHz to 750 MHz; LVCMOS inputs cover 8 kHz to 250 MHz. Input termination is configurable per channel, and the device detects loss-of-signal (LOS) and out-of-frequency (OOF) conditions autonomously.