Skyworks Solutions Inc. SI5338A-B01604-GM

Overview

SI5338A-B01604-GM from Skyworks Solutions is an I²C-programmable quad clock generator with four independent differential output drivers, 0.7 ps RMS typical phase jitter, PCIe Gen 1–4 Common Clock and Gen 3 SRNS compliance, and support for LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL output formats across 0.16–710 MHz. It replaces up to four crystal oscillators in high-speed serial interface timing applications such as PCIe root complexes and FPGA clock trees.

For engineers reviewing the SI5338A-B01604-GM datasheet, SI5338A-B01604-GM pinout, SI5338A-B01604-GM application, or SI5338A-B01604-GM equivalent, key selection criteria include its MultiSynth™ fractional-N synthesis architecture, per-output voltage configurability (1.5/1.8/2.5/3.3 V), independent phase/frequency adjustment (±45 ns / 1 ppm steps), and 24-pin 4×4 mm QFN package with integrated loss-of-lock and loss-of-signal alarms.

Technical Context

The SI5338A-B01604-GM implements a two-stage PLL architecture: a high-stability reference PLL (Stage 1) locks to one of six input sources (crystal, CMOS, SSTL/HSTL, or differential), followed by four independent MultiSynth™ fractional-N synthesis blocks (Stage 2) each driving a configurable output buffer. Each MultiSynth supports integer or fractional mode operation with <1 ppb frequency resolution and programmable initial phase offset (–45 to +45 ns).

Its output stage provides per-driver supply voltage selection (VDDO0–VDDO3), format flexibility (LVPECL up to 710 MHz, LVDS up to 350 MHz, HCSL up to 250 MHz, CMOS up to 200 MHz), and hardware- or I²C-triggered glitchless frequency increment/decrement (667 ns update time >18 MHz). Spread spectrum clocking is supported on any output (0.5–5.0% spread, 33–63 kHz modulation rate).

Key Specifications

Pinout & Package

SI5338A-B01604-GM uses a 24-pin QFN package (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are fixed per the Si5338 family: IN1/IN2 (differential ref 1), IN3/IN4 (single-ended ref 2), IN5/IN6 (differential ref 3), CLK0A/CLK0B through CLK3A/CLK3B (four differential output pairs), VDDO0–VDDO3 (independent output supply pins), VDD (core supply), SCL/SDA (I²C interface), INTR (interrupt output), and RSVD_GND (reserved ground).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5338A-B01604-GM, the Si5338A-B01605-GM offers identical electrical performance but reduces startup configuration time via factory programming, while the LMK04832RHAR trades integration density and power efficiency for superior jitter cleaning capability-making it appropriate only when input reference quality is insufficient for direct MultiSynth™ use.

Availability

SI5338A-B01604-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 server platforms, multi-rate Ethernet switching infrastructure, and FPGA-based broadcast video equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5338A-B01604-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 power management ICs for wireless, broadband, automotive, and industrial markets.

The Si5338 product line delivers highly configurable, low-jitter clock generation for high-speed serial interfaces-including PCIe, Ethernet, Fibre Channel, and telecom systems-enabling system architects to replace multiple discrete oscillators with a single programmable device.

FAQ

What is the primary function of the SI5338A-B01604-GM in a timing architecture?

The SI5338A-B01604-GM serves as an I²C-programmable quad clock generator that synthesizes four independent, low-jitter output clocks from a single reference input. Its MultiSynth™ architecture enables precise frequency generation (0.16–710 MHz) with 0 ppm error, making it ideal for replacing multiple crystal oscillators in PCIe, Ethernet, and FPGA-based systems. SI5338A-B01604-GM integrates PLL-based synthesis, configurable output drivers, and real-time frequency/phase tuning-all in a compact 4×4 mm QFN package.

Does the SI5338A-B01604-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338A-B01604-GM meets PCIe Gen 4 common clock jitter specifications with ≤0.45 ps RMS (12 kHz–20 MHz) when configured per Skyworks' recommended settings. It is explicitly listed as PCIe Gen 1/2/3/4 Common Clock and Gen 3 SRNS compliant in its official documentation. SI5338A-B01604-GM achieves this using its low-noise MultiSynth™ synthesis engine, optimized loop bandwidth (2–5 MHz), and differential output support (HCSL/LVDS) required for Gen 4 compliance.

How many reference inputs does the SI5338A-B01604-GM support, and what types are accepted?

The SI5338A-B01604-GM supports up to six reference inputs: two differential pairs (IN1/IN2 and IN5/IN6), two single-ended pins (IN3 and IN4), and two additional differential inputs (IN5/IN6 used as second differential pair). Accepted signal types include external crystals (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), and differential (5–710 MHz). SI5338A-B01604-GM automatically detects and selects among these based on configuration registers.

Can output voltage levels be configured independently for each clock channel on the SI5338A-B01604-GM?

Yes, the SI5338A-B01604-GM provides independent output supply pins VDDO0 through VDDO3, allowing each of the four differential output pairs (CLK0A/B through CLK3A/B) to operate at 1.5 V, 1.8 V, 2.5 V, or 3.3 V. This enables direct interfacing with mixed-voltage devices-for example, driving a 1.8 V FPGA bank and a 3.3 V Ethernet PHY simultaneously. SI5338A-B01604-GM maintains full specification compliance across all supported VDDO levels.

What software tools are available to configure the SI5338A-B01604-GM?

Skyworks' ClockBuilder Pro software is the official configuration tool for the SI5338A-B01604-GM. It provides graphical interface-based setup of output frequencies, formats, voltages, spread spectrum parameters, and I²C addresses, then generates register maps and configuration files. SI5338A-B01604-GM also supports in-system programming via standard I²C commands, and Skyworks offers the PCIe Clock Jitter Tool for validation against Intel's jitter compliance masks.