Skyworks Solutions Inc. SI5338C-B05412-GMR

Overview

SI5338C-B05412-GMR 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 from 1.8/2.5/3.3 V core supply. It replaces up to four crystal oscillators in high-speed serial interface timing applications such as PCIe switch cards and 10 GbE line cards.

For engineers reviewing the SI5338C-B05412-GMR datasheet, SI5338C-B05412-GMR pinout, SI5338C-B05412-GMR application, or SI5338C-B05412-GMR equivalent, key selection criteria include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz per output), independent output voltage control (1.5–3.3 V), ±20 ps phase step resolution, and 24-pin 4×4 mm QFN package with validated I²C/SMBus programming interface.

Technical Context

The SI5338C-B05412-GMR implements a two-stage PLL architecture: a high-stability reference stage followed by four independent MultiSynth™ fractional-N synthesizers, each driving a configurable output buffer. Its input supports eight reference sources - including external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), and differential (5–710 MHz) - enabling flexible system-level clock tree design.

Each of the four output drivers supports LVPECL, LVDS, HCSL, CML, CMOS, SSTL, or HSTL formats with independent supply voltage (VDDO0–VDDO3), programmable initial phase offset (±45 ns), and glitchless frequency increment/decrement in 1 ppm steps. The device includes loss-of-lock and loss-of-signal alarms, external feedback mode for zero-delay operation, and spread-spectrum clocking (0.5–5.0% spread, 33–63 kHz modulation).

Key Specifications

Pinout & Package

SI5338C-B05412-GMR uses a 24-pin, 4 × 4 mm QFN package with exposed thermal pad. Pin assignments are fixed across Si5338 family variants and validated per Skyworks Rev. 1.6 datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5332A-D05412-GM and ICS8430I-01T, SI5338C-B05412-GMR delivers optimal balance of programmability, jitter performance, and pin-compatible scalability within the Si5338 family - making it ideal for PCIe, Ethernet, and FPGA timing where field-upgradable frequency agility is essential.

Availability

SI5338C-B05412-GMR is available at Aetrix Electronics and suitable for PCIe switch timing, 10 GbE line card clocking, and FPGA processor clocking requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338C-B05412-GMR 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 product line was designed to replace multiple discrete oscillators with a single programmable clock generator for high-speed serial interfaces - targeting PCIe, Ethernet, and broadcast video systems demanding low jitter, flexible format support, and field-reprogrammability.

FAQ

What is the primary function of the SI5338C-B05412-GMR?

The SI5338C-B05412-GMR is an I²C-programmable quad clock generator that synthesizes four independent, low-jitter output clocks from a single reference input. It serves as a timing hub in systems like PCIe switches and 10 GbE line cards, replacing up to four discrete oscillators while enabling precise frequency, phase, and format control per output channel.

Does the SI5338C-B05412-GMR support PCIe Gen 4 timing requirements?

Yes, the SI5338C-B05412-GMR meets PCIe Gen 4 Common Clock jitter specifications (0.15–0.45 ps RMS) when configured per Skyworks AN562 guidelines. Its 0.7 ps RMS typical phase jitter, combined with optimized PLL bandwidth and differential output routing, ensures compliance under real-world conditions verified using the Skyworks PCIe Clock Jitter Tool.

Can the SI5338C-B05412-GMR generate different output voltages simultaneously?

Yes, the SI5338C-B05412-GMR supports independent output supply voltages (VDDO0–VDDO3) ranging from 1.5 V to 3.3 V. This allows simultaneous generation of LVDS (2.5 V), HCSL (1.8 V), and CMOS (3.3 V) signals on separate outputs - eliminating external level shifters in mixed-voltage FPGA or ASIC designs.

How is the SI5338C-B05412-GMR programmed in-system?

The SI5338C-B05412-GMR is programmed via its I²C/SMBus-compatible interface using Skyworks' ClockBuilder Pro software. Configuration is stored in on-chip OTP memory, enabling full functionality immediately after power-up. Pin-controlled frequency/phase adjustments are also supported for real-time tuning without host intervention.

What reference inputs does the SI5338C-B05412-GMR accept?

The SI5338C-B05412-GMR accepts eight reference types: 8–30 MHz crystal, 5–200 MHz CMOS, 5–350 MHz SSTL/HSTL, and 5–710 MHz differential (AC-coupled). Input flexibility enables direct connection to system clocks, GPS modules, or precision oscillators - all without external conditioning circuitry.