Skyworks Solutions Inc. SI5394D-A-GM

Overview

SI5394D-A-GM from Skyworks Solutions is a 4-input, 4-output ultra-low-jitter clock multiplier and jitter attenuator with external crystal reference, supporting integer-only synthesis up to 350 MHz output frequency, 69 fs RMS phase jitter (P-grade), and operation in free-run, locked, and holdover modes for telecom and high-speed SerDes applications.

For engineers reviewing the SI5394D-A-GM datasheet, SI5394D-A-GM pinout, SI5394D-A-GM application, or SI5394D-A-GM equivalent, key selection criteria include its 44-QFN 7×7 mm package, external XTAL reference architecture, 8 kHz–750 MHz differential input range, G.8262 SyncE compliance, and hitless switching capability for 56G/112G PAM4 clocking systems.

Technical Context

The SI5394D-A-GM implements a fourth-generation DSPLL® with programmable loop bandwidth (0.1 Hz–4 kHz) and Multi-Synth™ fractional/integer dividers, enabling any-frequency synthesis from any input while attenuating incoming jitter. Its architecture integrates four independent input receivers, status monitoring (LOS/OOF/LOL), and in-circuit programmable NVM for known-power-up configuration.

It supports enhanced hitless switching between fractionally related inputs (e.g., 8 kHz, 19.44 MHz, 25 MHz), dynamic phase adjust, and ramped frequency transitions during holdover exit or input switching - all controlled via I²C/SPI interface without requiring external components for crystal biasing.

Key Specifications

Pinout & Package

SI5394D-A-GM 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 Si5394 Family Reference Manual Rev. 1.4 (Section 5.1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5394C-A-GM and SI5344D-A-GM, the SI5394D-A-GM delivers optimal balance of ultra-low jitter (69 fs), integer-only synthesis efficiency, and modern holdover/ramping features - making it ideal for new 56G SerDes and SyncE line card designs where 350 MHz output ceiling is acceptable.

Availability

SI5394D-A-GM is available at Aetrix Electronics and suitable for 56G SerDes clocking, OTN transponder timing, and Synchronous Ethernet line cards requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5394D-A-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, with leadership in RF, timing, and precision analog products for infrastructure, automotive, and industrial markets.

The SI5394D-A-GM belongs to Skyworks' Si539x Any-Frequency Jitter Attenuator family, engineered specifically for next-generation telecom and datacom systems demanding sub-100-fs jitter, multi-input redundancy, and G.8262/G.8262.1 compliance.

FAQ

What is the maximum output frequency supported by the SI5394D-A-GM?

The SI5394D-A-GM supports an output frequency range of 100 Hz to 350 MHz in integer-only synthesis mode. This upper limit is specified in Skyworks' official ordering guide for Grade D devices and reflects its optimization for high-stability, low-jitter generation in telecom and networking applications where frequencies above 350 MHz are typically handled by dedicated RF synthesizers or higher-grade variants like SI5394C-A-GM.

Does the SI5394D-A-GM include an integrated crystal resonator?

No, the SI5394D-A-GM uses an external crystal (XTAL) or crystal oscillator (XO) connected to the XA/XB pins. It belongs to the A/B/C/D/P grade family, which requires external reference - unlike J/K/L/M/E grades that integrate the resonator. The device includes internal load capacitors, eliminating need for external CL components.

Which communication interfaces does the SI5394D-A-GM support for configuration?

The SI5394D-A-GM supports both I²C (SCL/SDA pins) and SPI (CLKIN/CLKOUT plus CSb) interfaces for register access and NVM programming. I²C is commonly used for initial setup and status monitoring, while SPI enables faster bulk configuration during production programming or field updates.

How does the SI5394D-A-GM handle loss of input clock signal?

Upon loss of the selected input clock, the SI5394D-A-GM automatically enters holdover mode using averaged historical frequency data (up to 120 seconds) stored during prior lock. Its output remains stable with drift governed by the external crystal's accuracy, and it supports ramped exit to minimize phase transients when the reference returns - a key feature for carrier-grade timing resilience.

Is the SI5394D-A-GM compliant with ITU-T G.8262 standards?

Yes, the SI5394D-A-GM meets ITU-T G.8262 (SyncE EEC Options 1 and 2) and G.8262.1 (Enhanced SyncE eEEC) requirements. Compliance is achieved through its DSPLL architecture, programmable loop bandwidth, holdover performance, and jitter transfer/wander characteristics - validated per Skyworks' published test reports and reference manual specifications.