Skyworks Solutions Inc. SI5338A-B05246-GM

Overview

SI5338A-B05246-GM from Skyworks Solutions is an I²C-programmable quad clock generator with four independently configurable differential or single-ended outputs, 0.7 ps RMS typical phase jitter, PCIe Gen 1–4 Common Clock and Gen 3 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 Ethernet switch/router, processor/FPGA clocking, and broadcast video timing systems.

For engineers reviewing the SI5338A-B05246-GM datasheet, SI5338A-B05246-GM pinout, SI5338A-B05246-GM application, or SI5338A-B05246-GM equivalent, key selection considerations include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz per output), independent output voltage support (1.5/1.8/2.5/3.3 V), spread-spectrum capability (0.5–5.0% down-spread), and I²C/SMBus programmability with ClockBuilder Pro software integration.

Technical Context

The SI5338A-B05246-GM implements a two-stage PLL architecture: a high-stability reference stage (with crystal or external clock input) followed by four independent MultiSynth™ fractional-N synthesizers, each driving a configurable output buffer. Its synthesis resolution is 1 ppb, enabling true zero-ppm frequency accuracy on all outputs.

Each output supports LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats with independent supply voltage (VDDOx), programmable initial phase offset (±45 ns), and glitchless frequency increment/decrement in 1 ppm steps. The device includes loss-of-lock and loss-of-signal alarms, external feedback mode for zero-delay operation, and configurable spread-spectrum modulation (33–63 kHz rate, 0.5–5.0% spread).

Key Specifications

Pinout & Package

SI5338A-B05246-GM is housed in a 24-lead, 4 × 4 mm QFN package with exposed thermal pad. Pin 1 is top-left corner (IN1), and pin numbering proceeds counterclockwise. The package supports reflow soldering per JEDEC J-STD-020 (peak 260 °C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5332A-D05286-GM, SI5338A-B05246-GM offers smaller footprint and lower cost but higher jitter; versus ICS8430I-01T, it provides full programmability and multi-standard compliance at the expense of fixed-frequency simplicity.

Availability

SI5338A-B05246-GM is available at Aetrix Electronics and suitable for Ethernet switch/router timing, PCIe Gen 3/4 clocking, and broadcast video/audio timing requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for SI5338A-B05246-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 for wireless, broadband, automotive, and industrial markets.

The Si5338 family is designed as a programmable, low-jitter clock generator platform targeting high-speed serial interface timing in networking, computing, and broadcast infrastructure where flexibility, precision, and PCIe/Ethernet compliance are critical.

FAQ

What is the maximum output frequency supported by SI5338A-B05246-GM in LVPECL format?

The SI5338A-B05246-GM supports LVPECL outputs up to 710 MHz, as confirmed in Table 6 of the datasheet. This capability enables direct clocking of high-speed SerDes lanes in 10G/25G Ethernet and CPRI interfaces without external frequency multiplication. Operation above 350 MHz is limited to two unique frequencies simultaneously (Fvco/4 and Fvco/6), and SI5338A-B05246-GM maintains 0.7 ps RMS jitter at 125 MHz and 156.25 MHz outputs.

Does SI5338A-B05246-GM support PCIe Gen 4 Common Clock architecture?

Yes, SI5338A-B05246-GM is explicitly compliant with PCIe Gen 4 Common Clock requirements, achieving 0.15–0.45 ps RMS jitter (Table 12) under specified conditions including PLL bandwidth of 2–5 MHz and CDR = 10 MHz. It meets the PCI-SIG Base Specification 4.0 rev. 0.5 jitter mask and is validated using the Skyworks PCIe Clock Jitter Tool. SI5338A-B05246-GM also supports Gen 1–3 and SRNS modes.

Can SI5338A-B05246-GM generate different output voltages on each channel?

Yes, SI5338A-B05246-GM provides independent VDDO0–VDDO3 supply pins, allowing each of its four output groups to operate at 1.5 V, 1.8 V, 2.5 V, or 3.3 V. This enables direct interfacing with mixed-voltage SoCs and FPGAs - for example, driving 1.8 V DDR4 PHYs, 3.3 V microcontroller peripherals, and 2.5 V transceivers simultaneously. SI5338A-B05246-GM's datasheet specifies output voltage ranges per format (e.g., LVDS at 1.8 V: VOC = 0.875 V typical).

How is SI5338A-B05246-GM programmed, and what tools are required?

SI5338A-B05246-GM is programmed via its I²C/SMBus-compatible interface (SCL/SDA pins) using Skyworks' ClockBuilder Pro software, which generates configuration files and supports real-time register editing. The tool auto-generates initialization code for MCU integration and validates frequency plans against jitter and phase noise constraints. SI5338A-B05246-GM also supports pin-controlled frequency increment/decrement and stores one factory-programmed configuration in OTP NVM for power-on default operation.

What is the thermal performance of SI5338A-B05246-GM in continuous operation?

SI5338A-B05246-GM has a junction-to-ambient thermal resistance (θJA) of 37 °C/W under still-air conditions and junction-to-case (θJC) of 10 °C/W (Table 4). With typical core current of 45 mA at 3.3 V (148.5 mW), self-heating is ~5.5 °C above ambient - well within the –40 to +85 °C operating range. The exposed thermal pad must be soldered to a PCB copper plane for optimal heat dissipation, and SI5338A-B05246-GM remains fully functional up to TJ = 150 °C (absolute max rating).