Skyworks Solutions Inc. SI5338M-B05848-GM

Overview

SI5338M-B05848-GM from Skyworks Solutions is a quad-output, I²C-programmable clock generator with MultiSynth™ frequency synthesis, delivering four independent low-jitter clocks (0.7 ps RMS typ) across LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL formats, supporting PCIe Gen 1–4 and Ethernet timing in telecom line cards and FPGA systems.

For engineers reviewing the SI5338M-B05848-GM datasheet, SI5338M-B05848-GM pinout, SI5338M-B05848-GM application, or SI5338M-B05848-GM equivalent, key selection factors include its 4× differential output capability, 0 ppm synthesis accuracy, 24-pin 4×4 mm QFN package, and PCIe Gen 3 SRNS compliance - all critical for high-speed serial interface clocking.

Technical Context

The SI5338M-B05848-GM integrates a dual-stage PLL architecture: a high-stability reference stage followed by four independent MultiSynth™ fractional-N synthesizers, each with programmable R/M/N dividers and phase/frequency increment/decrement control. It supports external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), and differential (5–710 MHz) inputs.

Each of its four output drivers is independently configurable for voltage (1.5/1.8/2.5/3.3 V), format, spread-spectrum modulation (0.5–5.0% at 33–63 kHz), and phase offset (<20 ps resolution). Loss-of-lock and loss-of-signal alarms provide real-time monitoring in mission-critical timing applications.

Key Specifications

Pinout & Package

SI5338M-B05848-GM uses a 24-lead, 4 × 4 mm QFN package with exposed thermal pad. Pin assignments are fixed per the Si5338 family: six input pins (IN1–IN6), eight output pins (CLK0A/B through CLK3A/B), four VDDOx supply pins, three power/ground pins (VDD, GND, RSVD_GND), and four control pins (SCL, SDA, INTR, OEB).

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B05848-GM, the SI5338M-B05848-GM offers identical hardware but enables full I²C reprogramming in-system; versus LMK04832RHAR, it delivers optimal cost, size, and power for mid-range communications timing without over-engineering.

Availability

SI5338M-B05848-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 server motherboards, 10/25 GbE switch fabric designs, and broadcast video processing equipment requiring stable component supply and long-term lifecycle support.

Supply support for SI5338M-B05848-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 product line was designed specifically for high-performance, multi-protocol clock generation in data center, telecom, and broadcast infrastructure - emphasizing low jitter, flexible I²C configurability, and compact QFN packaging.

FAQ

What is the primary function of the SI5338M-B05848-GM in a system design?

The SI5338M-B05848-GM serves as a quad-output, I²C-programmable clock generator that synthesizes four independent, low-jitter frequencies (0.16–710 MHz) from a single reference input. Its MultiSynth™ architecture enables zero-ppm accuracy and supports PCIe Gen 1–4, Ethernet, and broadcast video timing standards - replacing up to four discrete oscillators while maintaining tight jitter budgets. The SI5338M-B05848-GM is commonly used in switch/router line cards and FPGA-based acceleration platforms.

Does the SI5338M-B05848-GM support PCIe Gen 4 Common Clock compliance?

Yes, the SI5338M-B05848-GM meets PCIe Gen 4 Common Clock jitter requirements with 0.15–0.45 ps RMS jitter (10 kHz–50 MHz) when configured per Skyworks' recommended PLL bandwidth (2–4 MHz) and CDR settings. This is validated using the Skyworks PCIe Clock Jitter Tool and aligns with PCI-SIG Base Specification 4.0 rev. 0.5. The SI5338M-B05848-GM achieves this while delivering four independent outputs - a key differentiator versus single-output Gen 4 clock ICs.

Can the SI5338M-B05848-GM generate different output voltages simultaneously?

Yes, the SI5338M-B05848-GM supports independent output supply rails (VDDO0–VDDO3) set to 1.5 V, 1.8 V, 2.5 V, or 3.3 V per output pair. This allows simultaneous LVDS (2.5 V), HCSL (1.8 V), and CMOS (3.3 V) outputs without external level shifters - essential for interfacing with mixed-voltage FPGAs, ASICs, and PHYs. Each VDDO pin powers its corresponding CLKxA/CLKxB pair, and voltage selection is configured via I²C registers.

How is the SI5338M-B05848-GM programmed and configured?

The SI5338M-B05848-GM is programmed via its I²C/SMBus-compatible serial interface (SCL/SDA pins) using Skyworks' ClockBuilder Pro software. This GUI tool generates custom configuration files (.cbs) that define MultiSynth M/N/R dividers, output formats, voltage levels, spread-spectrum parameters, and phase offsets. Configuration can be loaded into volatile RAM at boot or written to one-time-programmable (OTP) NVM for autonomous startup - the SI5338M-B05848-GM retains full I²C reprogrammability even after OTP programming.

What package type and thermal characteristics does the SI5338M-B05848-GM have?

The SI5338M-B05848-GM uses a 24-pin QFN package measuring 4 mm × 4 mm with 0.5 mm pitch and an exposed thermal pad. Its thermal resistance is θJA = 37 °C/W (still air) and θJC = 10 °C/W, enabling reliable operation at full load (45 mA core current) across –40 °C to +85 °C ambient. The small footprint and low thermal impedance make it suitable for thermally constrained telecom line cards and high-density switch PCBs where the SI5338M-B05848-GM is often placed near SERDES or FPGA clock inputs.