Skyworks Solutions Inc. SI5344B-B03743-GMR

Overview

SI5344B-B03743-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 outputs from 100 Hz to 1028 MHz (differential) or 250 MHz (LVCMOS), meeting ITU-T G.8262 EEC Option 1/2 for Synchronous Ethernet in carrier-grade networking line cards.

For engineers reviewing the SI5344B-B03743-GMR datasheet, SI5344B-B03743-GMR pinout, SI5344B-B03743-GMR application, or SI5344B-B03743-GMR equivalent, key selection criteria include its 44-QFN 7×7 mm package, programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), hitless/automatic input switching, integrated loop filter, and factory-programmed configuration for SyncE-compliant timing in OTN transponders and 10/40/100G line cards.

Technical Context

The SI5344B-B03743-GMR implements a digitally controlled DSPLL with fully integrated loop filter and programmable loop bandwidth (0.1 Hz–4 kHz), enabling precise jitter filtering and holdover stability. Its MultiSynth output dividers support integer and fractional synthesis, while the crosspoint switch routes any synthesized frequency to any of four outputs.

It operates in freerun, locked, holdover, and zero-delay modes; supports gapped clock locking; provides status monitoring (LOS/OOF/LOL); and enables glitchless on-the-fly frequency changes via I²C/SPI interface with on-chip NVM for power-up configuration.

Key Specifications

Pinout & Package

The SI5344B-B03743-GMR 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 SI5344B-B03743-GMR, Si5344A-D-GM1 offers broader synthesis flexibility but requires ClockBuilder Pro setup, while LMK04832 prioritizes ultra-high-frequency precision over telecom compliance - making SI5344B-B03743-GMR optimal for drop-in SyncE deployment with guaranteed jitter and wander performance.

Availability

SI5344B-B03743-GMR is available at Aetrix Electronics and suitable for OTN transponders, Carrier Ethernet switches, and broadcast video equipment requiring stable component supply, long-term lifecycle assurance, and prequalified SyncE timing performance.

Supply support for SI5344B-B03743-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 infrastructure, automotive, and industrial markets.

The Si5344 family is designed specifically for high-reliability, jitter-critical timing applications in telecom and networking equipment - delivering certified SyncE performance with minimal external components and factory-configurable operation.

FAQ

What is the primary function of the SI5344B-B03743-GMR in a telecom timing system?

The SI5344B-B03743-GMR serves as a jitter-attenuating clock multiplier that cleans incoming reference clocks (e.g., from SyncE or OTN line interfaces) and generates multiple low-jitter output clocks for downstream PHYs, MACs, and framer ICs. Its DSPLL architecture achieves 90 fs rms jitter and meets ITU-T G.8262 EEC Option 1/2 - making SI5344B-B03743-GMR essential for maintaining phase integrity in carrier-grade infrastructure where wander and jitter directly impact service-level agreements.

Does the SI5344B-B03743-GMR require external loop filter components?

No, the SI5344B-B03743-GMR integrates the entire analog loop filter on-die, eliminating discrete capacitors and resistors traditionally needed in PLL designs. This integration removes sensitivity to PCB layout parasitics and board-level noise coupling - a key reliability advantage in dense line cards. The SI5344B-B03743-GMR's fully integrated loop filter is confirmed in the Si5345/44/42 Rev D datasheet Section 1, and contributes directly to its specified 90 fs rms jitter performance.

How does the SI5344B-B03743-GMR handle input clock failures in a redundant timing architecture?

Upon loss of the active input clock, the SI5344B-B03743-GMR automatically enters holdover mode using up to 120 seconds of stored frequency history to compute a stable averaged holdover frequency. This minimizes phase step at switchover - critical for hitless protection. The SI5344B-B03743-GMR also supports automatic input selection with priority-based fallback and glitchless pull-in to new references, ensuring continuous timing integrity without service interruption.

Can the SI5344B-B03743-GMR generate both LVDS and LVCMOS outputs simultaneously?

Yes, the SI5344B-B03743-GMR supports independent configuration of each of its four outputs for LVDS, LVPECL, LVCMOS, CML, or HCSL signaling - including mixed-mode operation. Each output has programmable amplitude, common-mode voltage (for differential), and slew rate. This capability is explicitly documented in the Si5345/44/42 Rev D datasheet Section 3.9.2 and enables SI5344B-B03743-GMR to drive heterogeneous loads (e.g., FPGA banks, SerDes PHYs, and legacy logic) from a single device.

Is the SI5344B-B03743-GMR preprogrammed, and can its configuration be modified after deployment?

Yes, SI5344B-B03743-GMR is factory preprogrammed with a specific SyncE-compliant configuration stored in one-time-programmable (OTP) NVM, enabling immediate operation at power-up. While the OTP memory is not reprogrammable in-system, the device retains full I²C/SPI configurability for runtime adjustments (e.g., input switching, output enable/disable, status monitoring). ClockBuilder Pro software can generate custom configurations for alternative part numbers like Si5344A-D-GM1, but SI5344B-B03743-GMR's preset remains fixed per ordering code B03743.