Skyworks Solutions Inc. SI5324D-C-GMR

Overview

SI5324D-C-GMR from Skyworks Solutions is a low-bandwidth, jitter-attenuating precision clock multiplier IC based on 3rd-generation DSPLL® technology. It accepts two differential input clocks (2 kHz–710 MHz), generates two independently programmable output clocks (2 kHz–945 MHz, up to 1.4 GHz at select ratios), delivers ultra-low jitter (290 fs rms, 12 kHz–20 MHz), supports I²C/SPI configuration, and operates from 1.8/2.5/3.3 V supply - used in OTN demapping, Synchronous Ethernet, and broadcast video genlock systems.

For engineers reviewing the SI5324D-C-GMR datasheet, SI5324D-C-GMR pinout, SI5324D-C-GMR application, or SI5324D-C-GMR equivalent, key selection criteria include its digitally programmable loop bandwidth (4–525 Hz), dual-input hitless switching with <200 ps phase step, compliance with ITU-T G.8251 and GR-253-CORE jitter specs, configurable LVPECL/LVDS/CML/CMOS outputs, and integrated loop filter eliminating external VCXO components.

Technical Context

The SI5324D-C-GMR implements a digitally controlled, low-loop-bandwidth DSPLL architecture with independent N1/N2/N31/N32 dividers enabling arbitrary frequency synthesis across its full range. Its core timing engine uses an external crystal or reference clock (XA/XB) as the stability anchor while accepting asynchronous CKIN1/CKIN2 inputs for flexible source selection.

It features tri-level rate-select pins (RATE0/RATE1), dedicated LOS/LOL/FOS alarm outputs, digital hold mode with historical frequency averaging, and phase build-out for seamless clock switching - all managed via register-based I²C or SPI control without requiring external compensation networks.

Key Specifications

Pinout & Package

SI5324D-C-GMR is housed in a Pb-free, RoHS-compliant 6 × 6 mm, 36-pin QFN package with exposed thermal pad. Pin functions are validated per Skyworks Rev. 1.1 datasheet (pages 60–63).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar jitter-attenuating clock multiplier applications.

Compared with Si5325D-C-GM and LTC6955IUF#PBF, the SI5324D-C-GMR uniquely balances jitter performance (290 fs), dual-input hitless switching, integrated loop filter, and broad frequency coverage - making it the optimal choice for carrier-grade OTN, SyncE, and broadcast infrastructure where reliability, standards compliance, and design simplicity are prioritized.

Availability

SI5324D-C-GMR is available at Aetrix Electronics and suitable for OTN demapping, Synchronous Ethernet, and broadcast video genlock applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SI5324D-C-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 leader in analog and mixed-signal semiconductors, specializing in RF, timing, and connectivity solutions for communications infrastructure, automotive, and industrial markets.

The SI5324D-C-GMR belongs to Skyworks' Si532x family of any-frequency jitter attenuators, engineered specifically for carrier-class timing in OTN, SyncE, and broadcast systems where sub-1 ps jitter, hitless redundancy, and standards compliance are non-negotiable.

FAQ

What is the maximum output frequency supported by the SI5324D-C-GMR?

The SI5324D-C-GMR supports up to 945 MHz across its full operating range; select configurations achieve 970–1134 MHz (N1 = 5) or 1.213–1.4 GHz (N1 = 4). CMOS outputs are limited to 212.5 MHz. These values are guaranteed per Skyworks Rev. 1.1 datasheet Table 3, and the SI5324D-C-GMR must be configured accordingly to meet frequency-grade limits.

Does the SI5324D-C-GMR support hitless clock switching between CKIN1 and CKIN2?

Yes, the SI5324D-C-GMR supports hitless input clock switching with phase build-out, limiting output phase disturbance to ≤200 ps during transitions - verified per Telcordia GR-253-CORE compliance testing. This behavior is inherent to the DSPLL architecture and requires no external circuitry; the SI5324D-C-GMR implements it autonomously upon detection of valid input clocks.

Which communication interfaces does the SI5324D-C-GMR support for configuration?

The SI5324D-C-GMR supports both I²C and SPI interfaces, selected via the CMODE pin. I²C uses SDA/SCL pins with 7-bit address; SPI uses SDI/SCLK/SDO/SS with standard timing (tDC = 40–60%, tcs ≥25 ns). Both protocols allow full register access and real-time reconfiguration of the SI5324D-C-GMR without reset.

What supply voltages are compatible with the SI5324D-C-GMR?

The SI5324D-C-GMR operates from a single supply: 1.8 V ±5%, 2.5 V ±10%, or 3.3 V ±10%. LVPECL outputs require ≥2.5 V nominal supply; CMOS drive strength scales with VDD (e.g., 32 mA max at 3.3 V). All specifications in the SI5324D-C-GMR datasheet are validated across this full voltage range and –40°C to +85°C ambient.

How does the SI5324D-C-GMR achieve jitter attenuation without external loop filter components?

The SI5324D-C-GMR integrates a fully digital loop filter within its 3rd-generation DSPLL® core, eliminating the need for external capacitors, resistors, or VCXOs. Loop bandwidth (4–525 Hz) is set via register writes, and filter coefficients are computed internally - enabling consistent jitter attenuation across temperature and voltage while reducing PCB area and component count for the SI5324D-C-GMR.