Skyworks Solutions Inc. SI5338M-B04122-GM

Overview

SI5338M-B04122-GM from Skyworks Solutions is a quad-output, I²C-programmable clock generator with MultiSynth™ frequency synthesis. It delivers four independent, any-frequency clocks (0.16–710 MHz) with 0.7 ps RMS typical phase jitter, PCIe Gen 1–4 compliance, and support for LVPECL/LVDS/HCSL/CMOS/SSTL outputs. It replaces up to four crystal oscillators in FPGA, processor, and Ethernet switch timing applications.

For engineers reviewing the SI5338M-B04122-GM datasheet, SI5338M-B04122-GM pinout, SI5338M-B04122-GM application, or SI5338M-B04122-GM equivalent, key selection criteria include differential output jitter performance (0.7 ps RMS), PCIe Gen 4 SRNS compliance, independent per-output voltage control (1.5–3.3 V), and I²C-configurable spread-spectrum modulation (0.5–5.0% at 33–63 kHz).

Technical Context

The SI5338M-B04122-GM implements a two-stage PLL architecture: a high-stability reference PLL (stage 1) locks to an external crystal or clock input (5–710 MHz), followed by four independent MultiSynth™ fractional-N synthesizers (stage 2) generating each output. Each synthesizer supports integer or fractional mode with <1 ppb frequency resolution and programmable initial phase offset (±45 ns).

It features dedicated control logic for loss-of-signal (2.6–5 µs detection), loss-of-lock (5–10 ms), and interrupt reporting via INTR pin. Output drivers are fully configurable per channel - including format (LVPECL/LVDS/HCSL/CMOS/SSTL), supply voltage (VDDOx = 1.4–3.63 V), and enable/disable - enabling mixed-signal timing in heterogeneous systems.

Key Specifications

Pinout & Package

SI5338M-B04122-GM uses a 24-lead, 4 × 4 mm QFN package with wettable flanks and an exposed thermal pad. Pin 1 is top-left (IN1), pin 24 is bottom-right (GND). 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-D06122-GM and ICS853S01AGI-01LFT, the SI5338M-B04122-GM offers unique trade-offs: full I²C programmability and broad input/output flexibility at moderate jitter, making it optimal for prototyping, multi-standard systems, and designs requiring post-silicon timing tuning.

Availability

SI5338M-B04122-GM is available at Aetrix Electronics and suitable for PCIe Gen 4 switch timing, Ethernet switch clocking, and FPGA/processor clocking requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338M-B04122-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 designed for high-performance, multi-protocol timing in datacenter, telecom, and broadcast systems - emphasizing low jitter, PCIe compliance, and software-configurable flexibility over fixed-function alternatives.

FAQ

What is the primary function of the SI5338M-B04122-GM?

The SI5338M-B04122-GM is a quad-output, I²C-programmable clock generator that synthesizes four independent, any-frequency clocks (0.16–710 MHz) with ultra-low phase jitter (0.7 ps RMS). It serves as a replacement for multiple crystal oscillators in systems requiring precise, flexible timing - such as PCIe Gen 4 switches, Ethernet routers, and FPGA-based accelerators. Its MultiSynth™ architecture ensures true zero-ppm frequency accuracy on all outputs.

Does the SI5338M-B04122-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338M-B04122-GM is explicitly validated for PCIe Gen 4 Common Clock compliance with 0.15–0.45 ps RMS jitter (10 kHz–50 MHz) and meets Gen 3 Separate Reference No Spread (SRNS) requirements at 0.11–0.32 ps RMS. These specifications are measured per PCI Express Base Specification 4.0 rev. 0.5 using the Intel Clock Jitter Tool and Skyworks' PCIe Clock Jitter Tool, confirming suitability for Gen 4 root complexes and endpoints.

How many input clock sources can the SI5338M-B04122-GM accept?

The SI5338M-B04122-GM supports up to six distinct input sources: two differential pairs (IN1/IN2 and IN5/IN6, 5–710 MHz), two single-ended inputs (IN3 and IN4, 5–350 MHz), and an integrated crystal oscillator interface (8–30 MHz on IN1/IN2). This allows flexible reference selection - e.g., using a 25 MHz crystal for stability and a 156.25 MHz CMOS clock for backup - without external multiplexing circuitry.

Can output voltage levels be configured independently per channel on the SI5338M-B04122-GM?

Yes, the SI5338M-B04122-GM provides four independent output supply rails (VDDO0–VDDO3), each configurable for 1.5 V, 1.8 V, 2.5 V, or 3.3 V. This enables mixed-signal interfacing - for example, driving 1.8 V LVDS I/O banks and 1.2 V HCSL transceivers simultaneously - without external level shifters. Each output driver's format (LVPECL/LVDS/HCSL/CMOS/SSTL) and voltage are set independently via I²C registers.

What development tools are supported for configuring the SI5338M-B04122-GM?

Skyworks' ClockBuilder Pro software fully supports the SI5338M-B04122-GM for GUI-based configuration, jitter simulation, and register file generation. It auto-generates I²C initialization scripts and validates PCIe/Ethernet timing compliance. Additionally, the free Skyworks PCIe Clock Jitter Tool enables rapid validation against Intel's jitter specification. Hardware evaluation requires the Si5338-EVB platform, which connects via USB-to-I²C bridge for real-time tuning.