Skyworks Solutions Inc. SI5338A-B04524-GMR

Overview

SI5338A-B04524-GMR from Skyworks Solutions is an I²C-programmable quad clock generator IC with four independently configurable differential or single-ended outputs, 0.7 ps RMS typical phase jitter, PCIe Gen 1–4 and SRNS compliance, and operation across –40 to +85 °C in a 4 × 4 mm 24-QFN package. It replaces up to four crystal oscillators in high-speed serial interface timing applications.

For engineers reviewing the SI5338A-B04524-GMR datasheet, SI5338A-B04524-GMR pinout, SI5338A-B04524-GMR application, or SI5338A-B04524-GMR equivalent, key selection considerations include its MultiSynth™ fractional-N synthesis architecture, independent output voltage per driver (1.5/1.8/2.5/3.3 V), spread-spectrum capability (0.5–5.0% down-spread), and support for differential input frequencies up to 710 MHz.

Technical Context

The SI5338A-B04524-GMR implements a two-stage PLL architecture: a high-performance integer-N Phase-Locked Loop (PLL) stage followed by four independent MultiSynth™ fractional-N synthesis blocks, each driving one output pair. This enables true zero-ppm frequency accuracy on all four outputs simultaneously.

It supports flexible reference inputs-including external crystals (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), and differential clocks (5–710 MHz)-and provides independent programmable phase offset (<20 ps steps), frequency increment/decrement (1 ppm steps), and spread-spectrum modulation (33–63 kHz rate, 0.5–5.0% spread) per output.

Key Specifications

Pinout & Package

SI5338A-B04524-GMR is housed in a 24-lead QFN package (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments follow Skyworks' standard Si5338 pinout: IN1/IN2 (diff input 1), IN3/IN4 (SE input), IN5/IN6 (diff input 2), CLK0A–CLK3B (four differential output pairs), VDD/VDDOx (core and output supply rails), SCL/SDA/INTR (I²C interface and interrupt), and RSVD_GND (reserved ground).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-output clock generator applications.

Compared with Si5332A-D06524-GM, SI5338A-B04524-GMR offers broader input reference support and lower system cost but trades off 0.35 ps RMS jitter and 1.4 GHz output ceiling; versus ICS8430I-01T, it delivers full programmability and PCIe Gen 4 compliance at the expense of fixed-function simplicity and lower unit price.

Availability

SI5338A-B04524-GMR is available at Aetrix Electronics and suitable for PCIe Gen 4 switch timing, 10 GbE routing, broadcast video synchronization, and FPGA clocking applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338A-B04524-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 infrastructure, automotive, and mobile markets.

The Si5338 product line was designed specifically for high-performance, multi-protocol clock generation in datacenter, telecom, and broadcast systems-emphasizing low jitter, software configurability, and compact packaging without sacrificing flexibility.

FAQ

What is the maximum differential input frequency supported by the SI5338A-B04524-GMR?

The SI5338A-B04524-GMR supports differential input frequencies up to 710 MHz on pins IN1/IN2 and IN5/IN6. This enables direct use of high-speed SerDes reference clocks (e.g., 622.08 MHz OC-12, 644.53125 MHz 10G-KR) without external division, preserving jitter performance and simplifying system design. The device maintains <0.225 ps RMS additive jitter in clock buffer mode at this frequency.

Does the SI5338A-B04524-GMR support PCIe Gen 4 Common Clock compliance?

Yes, the SI5338A-B04524-GMR is explicitly validated for PCIe Gen 4 Common Clock compliance with 0.15–0.45 ps RMS jitter (10 kHz–50 MHz band), measured per PCI-SIG specifications using the Intel Clock Jitter Tool. Its PLL loop bandwidth (1.6–4 MHz) and MultiSynth™ architecture meet the stringent phase noise and jitter floor requirements for Gen 4 link training and stable operation.

Can the SI5338A-B04524-GMR generate four different output frequencies simultaneously?

Yes, the SI5338A-B04524-GMR uses four independent MultiSynth™ fractional-N synthesizers to generate four fully independent output frequencies-from 0.16 MHz to 710 MHz-with true zero-ppm accuracy. Each output can be configured for different formats (LVDS, LVPECL, HCSL, etc.), voltages (1.5–3.3 V), and features (spread spectrum, phase offset), enabling complex multi-protocol timing in a single IC.

What is the purpose of the RSVD_GND pin on the SI5338A-B04524-GMR?

The RSVD_GND pin (Pin 21) on the SI5338A-B04524-GMR is a reserved ground terminal designated for PCB layout optimization and noise isolation. Though not internally connected to functional circuitry, it must be tied to the system ground plane to maintain signal integrity, reduce crosstalk between adjacent differential pairs (CLK2A/B and CLK3A/B), and ensure consistent thermal dissipation across the 24-QFN package's exposed pad.

How does the SI5338A-B04524-GMR handle loss-of-signal detection?

The SI5338A-B04524-GMR provides dedicated loss-of-signal (LOS) detection on all input pins (IN1–IN6) with programmable thresholds. Detection time is 2.6–5 µs, and release time is 0.01–1 µs. When triggered, the event asserts the open-drain INTR pin and updates corresponding status registers, enabling host firmware to initiate failover, logging, or reconfiguration-critical for telecom and industrial systems requiring high availability.