Skyworks Solutions Inc. SI5338N-B06121-GM

Overview

SI5338N-B06121-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 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 FPGA-based telecom line cards.

For engineers reviewing the SI5338N-B06121-GM datasheet, SI5338N-B06121-GM pinout, SI5338N-B06121-GM application, or SI5338N-B06121-GM equivalent, key selection criteria include its MultiSynth™-based any-frequency synthesis (0.16–710 MHz per output), independent output voltage per driver (1.5/1.8/2.5/3.3 V), spread-spectrum capability (0.5–5.0% down-spread), and 24-QFN package compatibility with space-constrained PCB layouts.

Technical Context

The SI5338N-B06121-GM implements a two-stage PLL architecture: a high-stability input stage with programmable R-divider followed by four independent MultiSynth™ fractional-N synthesis blocks, each feeding a configurable output driver. This enables true zero-ppm frequency accuracy across all outputs while supporting integer and fractional synthesis modes.

Each of the four output pairs (CLK0A/B through CLK3A/B) supports LVPECL, LVDS, HCSL, CML, SSTL, HSTL, or CMOS formats with independent VDDO supplies and programmable slew rate, phase offset (±45 ns), and frequency increment/decrement (1 ppm steps). Input flexibility includes external crystal (8–30 MHz), CMOS (5–200 MHz), SSTL/HSTL (5–350 MHz), or differential (5–710 MHz) references.

Key Specifications

Pinout & Package

SI5338N-B06121-GM uses a 24-lead QFN package (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignments are fixed per Skyworks Rev. 1.6 datasheet: IN1/IN2 (differential ref 1), IN3/IN4 (single-ended ref), IN5/IN6 (differential ref 2), CLK0A/CLK0B through CLK3A/CLK3B (four differential output pairs), VDD, VDDO0–VDDO3 (independent output supply pins), SCL/SDA (I²C interface), INTR (interrupt output), and GND/RSVD_GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si5332A-D06121-GM, SI5338N-B06121-GM offers field-programmability and broader input flexibility but higher jitter; versus ICS8430I-01T, it trades fixed-frequency simplicity for full any-frequency synthesis and multi-voltage support-making it optimal for prototyping and multi-standard platforms.

Availability

SI5338N-B06121-GM is available at Aetrix Electronics and suitable for PCIe switch timing, Ethernet PHY clocking, and FPGA-based telecom line card applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SI5338N-B06121-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, with leadership in RF, timing, and power management ICs for infrastructure, automotive, and mobile markets.

The Si5338 product line delivers programmable, low-jitter clock generation for high-speed serial interfaces-including PCIe, Ethernet, Fibre Channel, and SONET-enabling flexible, multi-protocol timing in space-constrained systems.

FAQ

What is the primary function of the SI5338N-B06121-GM in a timing architecture?

The SI5338N-B06121-GM serves as an I²C-programmable quad clock generator that synthesizes up to four independent, low-jitter output frequencies from a single reference input. Its MultiSynth™ technology enables zero-ppm accuracy across all outputs, making SI5338N-B06121-GM ideal for replacing multiple crystal oscillators in PCIe, Ethernet, and telecom timing applications.

Does the SI5338N-B06121-GM support PCIe Gen 4 timing requirements?

Yes, the SI5338N-B06121-GM meets PCIe Gen 4 common clock specifications with 0.15–0.45 ps RMS jitter (10 kHz–50 MHz) at 100 MHz HCSL output, validated per PCI-SIG Base Specification 4.0 rev. 0.5. It also complies with Gen 3 SRNS requirements at 0.11 ps RMS, confirmed using the Skyworks PCIe Clock Jitter Tool.

Can the SI5338N-B06121-GM generate different output voltages simultaneously?

Yes, the SI5338N-B06121-GM provides independent VDDO0–VDDO3 supply pins, allowing each of its four output drivers to operate at different voltages (1.4–3.63 V). This enables SI5338N-B06121-GM to drive mixed-voltage loads-such as a 1.8 V FPGA core and 3.3 V Ethernet PHY-without external level shifters.

How is the SI5338N-B06121-GM programmed and configured?

The SI5338N-B06121-GM is programmed via its I²C/SMBus-compatible interface using Skyworks' ClockBuilder Pro software. This GUI tool generates custom configuration files, validates timing constraints, and writes settings to the device's one-time-programmable (OTP) memory or volatile RAM-enabling rapid SI5338N-B06121-GM prototyping and field updates.

What package type and thermal characteristics does the SI5338N-B06121-GM use?

The SI5338N-B06121-GM uses a 24-pin QFN package (4 × 4 mm, 0.5 mm pitch) with exposed thermal pad. Its thermal resistance is θJA = 37 °C/W (still air), and θJC = 10 °C/W, enabling reliable operation at full load within the –40 to +85 °C industrial temperature range without forced airflow-critical for SI5338N-B06121-GM deployment in sealed telecom enclosures.