Skyworks Solutions Inc. SI5338L-B04837-GM

Overview

SI5338L-B04837-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 and 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 clock trees.

For engineers reviewing the SI5338L-B04837-GM datasheet, SI5338L-B04837-GM pinout, SI5338L-B04837-GM application, or SI5338L-B04837-GM equivalent, key selection criteria include output format flexibility (LVPECL/LVDS/HCSL/CMOS), independent per-output voltage control (1.5–3.3 V), MultiSynth™ fractional synthesis resolution (1 ppb), spread-spectrum capability (0.5–5.0% down-spread), and I²C/SMBus programmability with ClockBuilder Pro support.

Technical Context

The SI5338L-B04837-GM implements a two-stage PLL architecture: a high-stability integer-N PLL for reference conditioning followed by four independent MultiSynth™ fractional-N synthesis blocks, each driving one output channel. This enables true zero-ppm frequency accuracy on all four outputs simultaneously, even at non-integer multiples of the input reference.

Each output supports independent configuration of signal format, supply voltage (VDDOx), termination, phase offset (±45 ns, <20 ps step), and frequency increment/decrement (1 ppm steps, glitchless). Input options include external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), or differential (5–710 MHz), with loss-of-signal and loss-of-lock alarms.

Key Specifications

Pinout & Package

SI5338L-B04837-GM uses a 24-lead, 4 × 4 mm QFN package with exposed thermal pad. Pin 1 is top-left corner (IN1), pin 24 is bottom-right (GND). The package supports JEDEC-standard reflow and provides low thermal resistance (θ_JA = 37 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5332A-D05894-GM and ICS853S01AGI-01LFT, the SI5338L-B04837-GM uniquely balances field-programmability, PCIe Gen 4 compliance, and 4-output flexibility in a compact 24-QFN footprint-making it optimal for mid-generation upgrades and mixed-signal FPGA platforms where design reuse and layout efficiency are critical.

Availability

SI5338L-B04837-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 server motherboards, 10GbE switching infrastructure, broadcast video processing systems, and telecom line cards requiring stable component supply and long-term lifecycle assurance.

Supply support for SI5338L-B04837-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 infrastructure, automotive, and mobile markets.

The SI5338 family is engineered for high-performance clock generation in datacenter, networking, and broadcast equipment-delivering ultra-low jitter, flexible output configurations, and robust programmability to replace multiple discrete timing components.

FAQ

What is the maximum output frequency supported by the SI5338L-B04837-GM?

The SI5338L-B04837-GM supports up to 710 MHz on LVPECL/LVDS/CML outputs, 350 MHz on SSTL/HSTL, 250 MHz on HCSL, and 200 MHz on CMOS. Frequencies above 350 MHz are limited to two unique values simultaneously (Fvco/4 and Fvco/6), as defined in the synthesis architecture. All outputs maintain 0.7 ps RMS jitter at 100 MHz HCSL, meeting PCIe Gen 4 specifications.

Does the SI5338L-B04837-GM support PCIe Gen 4 Common Clock mode?

Yes, the SI5338L-B04837-GM is compliant with PCIe Gen 4 Common Clock mode, delivering ≤0.45 ps RMS jitter (10 kHz–50 MHz) at 100 MHz HCSL output with PLL bandwidth set to 2–4 MHz and CDR at 10 MHz. This satisfies the PCI-SIG Base Specification 4.0 rev. 0.5 requirement for total jitter ≤33.6 ps pk-pk.

How is the SI5338L-B04837-GM programmed, and what software is required?

The SI5338L-B04837-GM is programmed via its I²C/SMBus interface using Skyworks' ClockBuilder Pro software, which provides GUI-based configuration, real-time jitter simulation, and one-click register file generation. The software supports full device initialization, output format assignment, spread-spectrum setup, and phase/frequency tuning-enabling complete SI5338L-B04837-GM configuration without manual register coding.

Can the SI5338L-B04837-GM operate with a 25 MHz crystal input?

No-the SI5338L-B04837-GM supports external crystals only in the 8–30 MHz range, and 25 MHz falls within that range. However, crystal drive level must not exceed 100 µW, and load capacitance must be matched to the on-chip 11–13 pF range (recommended 17–19 pF with external caps). For 25 MHz operation, use AN360 guidelines to configure CL registers and verify rESR ≤100 Ω.

What are the thermal characteristics of the SI5338L-B04837-GM in continuous operation?

The SI5338L-B04837-GM has a junction-to-ambient thermal resistance (θ_JA) of 37 °C/W under still-air conditions and junction-to-case (θ_JC) of 10 °C/W. At full load (100 MHz on all outputs, 25 MHz refclk), core supply current is 45 mA typical, resulting in ~150 mW dissipation. With proper PCB copper pour under the exposed pad, junction temperature remains ≤85 °C at 85 °C ambient-ensuring reliable operation across the full industrial temperature range.