Skyworks Solutions Inc. SI5338L-B04358-GM

Overview

SI5338L-B04358-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. It replaces up to four crystal oscillators in high-speed serial interface timing applications such as PCIe root complexes and FPGA-based compute platforms.

For engineers reviewing the SI5338L-B04358-GM datasheet, SI5338L-B04358-GM pinout, SI5338L-B04358-GM application, or SI5338L-B04358-GM equivalent, key selection criteria 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 24-pin 4×4 mm QFN package with I²C/SMBus control interface.

Technical Context

The SI5338L-B04358-GM implements a two-stage PLL architecture: a high-stability input stage with programmable R-divider followed by a fractional-N MultiSynth™ synthesis stage per output path. Each of the four output drivers supports independent format selection (LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL) and voltage rail (VDDO0–VDDO3).

It accepts multiple reference inputs - external 8–30 MHz crystal, CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), or differential (5–710 MHz) - and enables glitchless frequency adjustment in 1 ppm steps and phase tuning in <20 ps increments. Loss-of-lock and loss-of-signal alarms are integrated for system monitoring.

Key Specifications

Pinout & Package

SI5338L-B04358-GM is housed in a 24-lead, 4 × 4 mm QFN package with exposed thermal pad. Pin assignments follow Skyworks' standard Si5338 pinout: six input pins (IN1–IN6), eight clock output terminals (CLK0A/B through CLK3A/B), four VDDO supply rails (VDDO0–VDDO3), dual core VDD, SCL/SDA/I²C interface, INTR interrupt, and ground/pad connections.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI5338L-B04358-GM, the Si5332A-D06989-GM offers superior jitter and integrated crystal but requires PCB redesign, while the ICS8430I-01LG provides lower cost and simpler interface at the expense of configurability and jitter performance.

Availability

SI5338L-B04358-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 server motherboards, 10 GbE switching infrastructure, and FPGA-based broadcast video equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338L-B04358-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 leader in analog and mixed-signal semiconductors, specializing in RF, timing, and connectivity solutions for communications, automotive, and industrial markets.

The Si5338 family is designed for high-performance, programmable clock generation in datacenter, networking, and broadcast video systems where flexibility, low jitter, and multi-format output capability are critical.

FAQ

What is the maximum output frequency supported by SI5338L-B04358-GM in LVPECL mode?

The SI5338L-B04358-GM supports LVPECL outputs up to 710 MHz, as confirmed in Table 6 of the datasheet. This applies when operating in integer synthesis mode with appropriate VDDO supply (2.5 V or 3.3 V) and proper termination (50 Ω to VDDO–2 V). Frequencies above 350 MHz are limited to two unique values simultaneously (Fvco/4 and Fvco/6).

Does SI5338L-B04358-GM support PCIe Gen 4 Separate Reference No Spread (SRNS) mode?

No - SI5338L-B04358-GM is compliant with PCIe Gen 4 Common Clock mode (≤0.45 ps RMS jitter), but it does not support Gen 4 SRNS. The datasheet explicitly lists SRNS compliance only for PCIe Gen 3. For Gen 4 SRNS, Skyworks recommends the Si5332 or Si534x families.

Can SI5338L-B04358-GM generate four different output frequencies simultaneously?

Yes - the SI5338L-B04358-GM uses four independent MultiSynth™ engines, allowing simultaneous synthesis of four distinct frequencies (e.g., 100 MHz, 125 MHz, 156.25 MHz, and 312.5 MHz), each with independent format, voltage, phase, and spread-spectrum settings.

What is the minimum input clock frequency supported in PLL bypass (buffer) mode for SI5338L-B04358-GM?

In PLL bypass mode, SI5338L-B04358-GM supports input frequencies as low as 1 MHz on single-ended inputs (IN3/IN4), though loss-of-signal detection is disabled below 5 MHz. Differential inputs (IN1/IN2, IN5/IN6) require ≥5 MHz for full functionality including LOS monitoring.

Is an external crystal required for SI5338L-B04358-GM operation?

No - SI5338L-B04358-GM supports multiple reference sources: external 8–30 MHz crystal, CMOS clock (5–200 MHz), or differential clock (5–710 MHz). Crystal use is optional; the device can operate entirely from an external clock source without any crystal.