Skyworks Solutions Inc. SI5345B-B04151-GMR

Overview

SI5345B-B04151-GMR from Skyworks is a 10-channel, any-frequency jitter attenuator/clock multiplier featuring fourth-generation DSPLL™ and MultiSynth™ technologies. 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 in free-run, synchronous, or holdover modes - deployed in OTN transponders and SyncE-compliant carrier Ethernet switches.

For engineers reviewing the SI5345B-B04151-GMR datasheet, SI5345B-B04151-GMR pinout, SI5345B-B04151-GMR application, or SI5345B-B04151-GMR equivalent, key selection considerations include its G.8262 EEC Option 1/2 compliance, programmable jitter attenuation bandwidth (0.1 Hz–4 kHz), 64-QFN 9×9 mm package, I²C/SPI configurability, and factory-programmed NVM configuration for known-power-up behavior.

Technical Context

The SI5345B-B04151-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 architecture supports fractional-N synthesis across all 10 outputs, allowing independent generation of any output frequency from any input frequency.

It features hitless and glitchless input switching between up to four inputs (IN0–IN3), status monitoring (LOS/OOF/LOL), and configurable holdover using averaged historical frequency data over up to 120 seconds - critical for maintaining phase continuity during input failure in telecom infrastructure.

Key Specifications

Pinout & Package

The SI5345B-B04151-GMR is housed in a 64-pin QFN package (9 mm × 9 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per Skyworks Si5345 pinout documentation (Rev D, Section 9).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5345B-B04151-GMR, Si5345A-D-GM1 offers broader synthesis flexibility but requires field programming, while LMK04832 provides more outputs and JESD204B support at higher power and reduced holdover robustness - making SI5345B-B04151-GMR optimal for drop-in SyncE/OTN deployments needing guaranteed startup behavior.

Availability

SI5345B-B04151-GMR is available at Aetrix Electronics and suitable for OTN transponders, SyncE carrier switches, broadcast video infrastructure, and test equipment requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for SI5345B-B04151-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 Si5345 family is engineered for high-performance timing in telecom infrastructure, delivering jitter-attenuated, multi-output clock synthesis with factory-programmed reliability for carrier-grade SyncE and OTN systems.

FAQ

What is the primary function of the SI5345B-B04151-GMR in a telecom timing system?

The SI5345B-B04151-GMR serves as a jitter-attenuating clock multiplier that cleans and regenerates timing signals in OTN and SyncE systems. It locks to noisy or wandering input references (e.g., recovered client clocks), suppresses jitter via its digitally programmable DSPLL, and generates up to 10 ultra-low-jitter outputs - ensuring SI5345B-B04151-GMR meets ITU-T G.8262 EEC Option 1/2 specifications for carrier Ethernet applications.

Does the SI5345B-B04151-GMR require external loop filter components?

No, the SI5345B-B04151-GMR integrates the entire DSPLL loop filter on-chip. This eliminates external passive components, reduces PCB area, and prevents noise coupling issues common in discrete filter implementations - a key advantage confirmed in the Si5345/44/42 Rev D datasheet Section 1.

How does the SI5345B-B04151-GMR handle loss of input reference?

Upon input failure, the SI5345B-B04151-GMR automatically enters holdover mode using up to 120 seconds of stored frequency history to compute a stable average holdover frequency. This minimizes phase disturbance at outputs - a behavior explicitly documented in Section 3.4.5 of the Rev D datasheet and validated for SI5345B-B04151-GMR's factory-programmed configuration.

What clock output formats does the SI5345B-B04151-GMR support?

The SI5345B-B04151-GMR supports LVDS, LVPECL, LVCMOS, CML, and HCSL output signaling with programmable amplitude and common-mode voltage. Each of its 10 outputs can be independently configured per Section 3.9.2 of the Rev D datasheet - enabling direct interfacing with diverse SERDES, FPGA, and ASIC clock inputs without level-shifting circuitry.

Is the SI5345B-B04151-GMR preprogrammed, and can it be reconfigured in-circuit?

Yes, SI5345B-B04151-GMR is factory preprogrammed with a specific frequency plan (B04151) stored in one-time-programmable (OTP) NVM, ensuring known-power-up behavior. It also supports in-circuit reprogramming via I²C or SPI per Section 3.11 - allowing field updates or temporary configuration changes without replacing the device.