The role of a clock generator

Traditionally, designs commonly used individual crystal oscillators or crystal resonators, but in recent years, with the increasing sophistication of systems, there has been a growing consideration of adopting clock generators, and this trend is expected to continue.

This chapter will briefly explain the role of a clock generator.

A clock generator is a device that uses a crystal oscillator or an externally input clock as a reference and generates and outputs multiple frequencies by dividing and multiplying them using an internal PLL (phase-locked loop) and a subsequent frequency divider.

When synchronization is not required, a crystal oscillator is used as the source to generate the desired clock. On the other hand, when synchronization is required, an external clock is used as a reference, and a PLL generates a clock that tracks the reference clock.

Thus, a clock generator has the following functions:
- Generation of multiple clocks
• Frequency conversion (frequency division/multiplication)
Clock distribution

These features make it possible to consolidate circuits that previously consisted of multiple clock ICs into a single clock generator.

As a result, it becomes possible to reduce the board area and the number of components, ultimately contributing to cost reduction.

Skyworks Clock Generator Product Lineup

The following is a list of Skyworks' clock generator product lineup.

In recent years, the demand for high-precision clock quality has been increasing in data centers, telecommunications infrastructure, broadcasting equipment, industrial equipment, and other applications.
Skyworks' clock generator product line meets these demands.

Skyworks offers industry-leading low-jitter performance and flexible, customizable tools.

Below is a list of clock generator products.

Products on the left side of the slide offer lower jitter, while those on the right have higher jitter but are also more affordable.

Introducing Skyworks Clock Generators

Latest Clock Generator SKY62101

Skyworks' latest clock generator, the SKY62101, is a next-generation timing device featuring ultra-low jitter performance and flexible clock generation capabilities.

It is suitable for generating clocks for high-speed interfaces such as data centers, AI accelerators, and communication equipment.

This device achieves ultra-low jitter performance equivalent to 55fs and is compatible with next-generation high-speed interfaces such as PCIe Gen7.

The latest jitter cleaners, SKY63104/5/6, are pin-compatible, allowing you to flexibly choose the device that best suits your input clock jitter reduction requirements.

Highly versatile clock generator Si5332

This article introduces the Si5332, a multi-functional and programmable clock generator that utilizes Skyworks' proprietary MultiSynth technology.

With up to 12 outputs, it can flexibly set and generate frequencies, even complex frequencies with decimal points, using its internal fractional frequency divider (MultiSynth).

Furthermore, it supports multiple output formats in single-ended and differential configurations. This product can also be used for PCIe Gen1 to Gen6 applications.

Therefore, it is suitable for a wide range of applications, including not only PCIe applications but also industrial equipment, video equipment, and communication equipment.

More detailed articles about Si5332 can be viewed at the following link.

Programmable Clock Generator Si5332

Low-jitter and flexible frequency setting clock generator Si534x/Si5391

Among Skyworks' clock generators, the Si539x and Si534x series are widely used as reference clocks for FPGAs and SoCs.

It has been adopted as a reference design and is used in a wide range of fields, including telecommunications equipment, data center equipment, and industrial equipment.

The difference between the Si534x and Si5391 lies in their jitter performance and output line count.

This is an Si5391 (12ch) unit. Its jitter performance is equivalent to 69fs.

These are Si5340 (4ch) and Si5341 (10ch) models. Jitter performance is equivalent to 100fs.

Furthermore, since the Si5391 and Si5341 are pin-compatible, systems already using the Si5341 can improve performance by replacing it with the Si5391 without changing the basic design.

This compatibility offers benefits such as improved clock jitter performance, system performance upgrades, and reduced design change risks.

Summary

A clock generator is a device that generates the required frequency using an internal PLL and frequency divider, based on a reference crystal oscillator or input clock.

Because it can generate multiple different frequencies simultaneously from a single reference clock, it is possible to supply the optimal clock for systems that incorporate multiple devices such as FPGAs, SoCs, CPUs, and ASICs.

Furthermore, if you already have many existing crystal oscillators and distributors, consolidating them into a single clock generator can lead to benefits such as lowering BOM costs.

Skyworks clock generators are low-jitter devices with flexible frequency settings,

It is used in a wide range of application fields, including high-speed communication equipment, industrial equipment, video equipment, and data center equipment.