Skyworks Solutions Inc. SI5338N-B04374-GMR

Overview

SI5338N-B04374-GMR from Skyworks Solutions is an I²C-programmable quad clock generator with four independently configurable differential outputs, 0.7 ps RMS typical phase jitter, PCIe Gen 1–4 Common Clock and Gen 3 SRNS compliance, and support for LVPECL/LVDS/HCSL/CMOS/SSTL/HSTL output formats across 0.16–710 MHz. 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 SI5338N-B04374-GMR datasheet, SI5338N-B04374-GMR pinout, SI5338N-B04374-GMR application, or SI5338N-B04374-GMR equivalent, key selection criteria include its MultiSynth™ fractional-N synthesis architecture, independent per-output voltage (1.5/1.8/2.5/3.3 V), 1 ppm frequency increment/decrement capability, <20 ps phase step resolution, and 24-pin 4×4 mm QFN package with integrated loss-of-lock and loss-of-signal monitoring.

Technical Context

The SI5338N-B04374-GMR implements a two-stage PLL architecture: a high-stability reference stage followed by four independent MultiSynth™ synthesis blocks, each driving one output pair (CLKxA/CLKxB). Its patented fractional-N synthesis enables any-frequency generation with zero-ppm accuracy on all outputs when configured in integer mode.

Input flexibility includes external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), or differential (5–710 MHz) references. Output drivers support independent format selection, voltage assignment, spread-spectrum modulation (0.5–5.0% spread, 33–63 kHz rate), and glitchless frequency/phase adjustment via pin control or I²C.

Key Specifications

Pinout & Package

SI5338N-B04374-GMR uses a 24-pin, 4 × 4 mm QFN package with exposed thermal pad. Pin 1 is top-left (IN1), pin numbering proceeds counterclockwise. The package supports reflow soldering per JEDEC J-STD-020 (peak 260 °C) and provides 37 °C/W junction-to-ambient thermal resistance in still air.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5338A-B04374-GM, SI5338N-B04374-GMR offers full I²C runtime reconfiguration and factory-locked boot behavior; versus LMK04832ISQE/NOPB, it delivers superior integration density and per-output voltage flexibility at lower power, but lacks JESD204B-specific features.

Availability

SI5338N-B04374-GMR is available at Aetrix Electronics and suitable for PCIe Gen 4 switch designs, FPGA-based 10G/25G Ethernet line cards, and broadcast video equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SI5338N-B04374-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 semiconductor company specializing in analog and mixed-signal connectivity solutions for wireless, broadband, automotive, and industrial markets.

The Si5338 product line was designed for high-performance, space-constrained timing applications requiring multi-frequency synthesis, low jitter, and flexible signal formatting-targeting PCIe, Ethernet, broadcast video, and FPGA/ASIC clocking.

FAQ

What is the primary function of the SI5338N-B04374-GMR in a timing architecture?

The SI5338N-B04374-GMR serves as an I²C-programmable quad clock generator that synthesizes four independent, low-jitter output clocks from a single reference input. Its MultiSynth™ architecture enables precise any-frequency generation (0.16–710 MHz) with 0.7 ps RMS typical phase jitter, making SI5338N-B04374-GMR ideal for replacing multiple crystal oscillators in PCIe, Ethernet, and FPGA timing systems.

Does the SI5338N-B04374-GMR support PCIe Gen 4 Common Clock compliance?

Yes, the SI5338N-B04374-GMR is validated for PCIe Gen 4 Common Clock topology with 0.15–0.45 ps RMS jitter (10 kHz–50 MHz) under specified conditions (PLL BW 2–4 MHz, CDR = 10 MHz), meeting PCI-Express Base Specification 4.0 rev 0.5 requirements. This performance is confirmed using the Skyworks PCIe Clock Jitter Tool and Intel Clock Jitter Tool v1.6.4.

How many independent output voltage supplies does the SI5338N-B04374-GMR support?

The SI5338N-B04374-GMR supports four independent output buffer supply rails (VDDO0–VDDO3), each configurable for 1.5 V, 1.8 V, 2.5 V, or 3.3 V. This allows direct interfacing with mixed-voltage components-such as 1.8 V FPGAs, 2.5 V SERDES, and 3.3 V legacy logic-without external level shifters, a key design advantage of the SI5338N-B04374-GMR.

Can the SI5338N-B04374-GMR generate different frequencies on each output simultaneously?

Yes, the SI5338N-B04374-GMR uses four independent MultiSynth™ synthesis blocks to generate distinct frequencies on each of its four differential output pairs (CLK0A/B through CLK3A/B). Each output supports frequencies from 0.16 MHz to 710 MHz (depending on format), with zero-ppm accuracy in integer mode and sub-ppb resolution in fractional mode-core functionality of the SI5338N-B04374-GMR.

What is the purpose of the INTR pin on the SI5338N-B04374-GMR?

The INTR pin on the SI5338N-B04374-GMR is an open-drain interrupt output that signals loss-of-lock (LOL) and loss-of-signal (LOS) events. It asserts low within 10 ms of LOL detection and 5 µs of LOS detection, enabling host processors to implement real-time fault recovery. This dedicated status monitoring is integral to the SI5338N-B04374-GMR's reliability in telecom and industrial applications.