Si5351A/B/C

I2C-PROGRAMMABLE ANY-FREQUENCY CMOS CLOCK GENERATOR + VCXO

Features

Generates up to 8 non-integer-related frequencies from 8 kHz to 160 MHz

I2C user definable configuration

Exact frequency synthesis at each output (0 ppm error)

Highly linear VCXO

Optional clock input (CLKIN)

Low output period jitter: 100 ps pp

Configurable spread spectrum selectable at each output

Operates from a low-cost, fixed frequency crystal: 25 or 27 MHz

Supports static phase offset

Programmable rise/fall time control

Glitchless frequency changes

Separate voltage supply pins: Core VDD: 2.5 or 3.3 V Output VDDO: 1.8, 2.5, or 3.3 V

Excellent PSRR eliminates external power supply filtering

Very low power consumption

Adjustable output-output delay

Available in 3 packages types: 10-MSOP: 3 outputs 24-QSOP: 8 outputs 20-QFN (4x4 mm): 8 outputs

PCIE Gen 1 compliant

Supports HCSL compatible swing

10-MSOP

24-QSOP

Applications

HDTV, DVD/Blu-ray, set-top box

Residential gateways

Audio/video equipment, gaming

Networking/communication

Printers, scanners, projectors

Servers, storage

 

 

XO replacement

Description

The Si5351 is an I2C configurable clock generator that is ideally suited for replacing crystals, crystal oscillators, VCXOs, phase-locked loops (PLLs), and fanout buffers in cost-sensitive applications. Based on a PLL/VCXO + high resolution MultiSynth fractional divider architecture, the Si5351 can generate any frequency up to 160 MHz on each of its outputs with 0 ppm error. Three versions of the Si5351 are available to meet a wide variety of applications. The Si5351A generates up to 8 free-running clocks using an internal oscillator for replacing crystals and crystal oscillators. The Si5351B adds an internal VCXO and provides the flexibility to replace both free-running clocks and synchronous clocks. The Si5351B eliminates the need for higher cost, custom pullable crystals while providing reliable operation over a wide tuning range. The Si5351C offers the same flexibility but synchronizes to an external reference clock (CLKIN).

20-QFN

Ordering Information:

See page 66

Functional Block Diagram

XA

XB

I2C

SSEN

OEB

 

 

 

 

 

 

 

Multi

 

 

 

 

XA

 

 

 

PLLA

 

 

 

Synth

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OSC

 

 

 

 

 

 

Multi

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Synth

 

 

 

 

 

 

 

 

 

 

PLLB

 

 

 

1

 

 

 

 

XB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VC

Multi

Synth

N

Si5351A

N = 2 or 7

I2C

SSEN

OEB

OSC PLL

VCXO

Multi

XA

Synth

 

0

 

Multi

 

Synth

XB

1

Multi

Synth

2CLKIN

Multi Synth

Multi

Synth

4

Multi

Synth

5

Multi

Synth

6

Multi

 

 

I2C

Synth

 

 

 

 

 

 

7INTR

Si5351B OEB

OSC

PLLA

PLLB

Multi

Synth

0

Multi

Synth

1

Multi

Synth

2

Multi

Synth

3

Multi

Synth

4

Multi

Synth

5

Multi

Synth

6

Multi

Synth

7

Si5351C

Preliminary Rev. 0.95 8/11

Copyright © 2011 by Silicon Laboratories

Si5351A/B/C

This information applies to a product under development. Its characteristics and specifications are subject to change without notice.

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Silicon Laboratories SI5351A/B/C specifications Features, Applications, Description, Functional Block Diagram

SI5351A/B/C specifications

Silicon Laboratories SI5351A/B/C is a versatile, low-power clock generator and frequency synthesizer that has gained widespread popularity in various applications, including telecommunications, consumer electronics, and industrial control systems. These devices are primarily designed to provide precise clock frequency generation with low phase noise and jitter, making them ideal for high-performance applications.

One of the standout features of the SI5351 is its ability to generate multiple output frequencies simultaneously. Capable of producing up to three independent programmable outputs, the SI5351A/B/C can generate frequencies ranging from 8 kHz to 160 MHz. With its integrated phase-locked loop (PLL) technology, it achieves excellent frequency stability and accuracy, simplifying the design of frequency-dependent systems.

The device operates under a supply voltage range of 1.8V to 3.6V, allowing it to be used in battery-powered applications without excessive power consumption. The SI5351’s low current draw, typically as low as 25 mA, is especially beneficial in portable devices, extending battery life and enhancing overall efficiency. Furthermore, it features a programmable output driver, which can be set to various drive strengths, ensuring compatibility with a wide array of load requirements.

Configuration and control of the SI5351 are user-friendly, implemented via an I2C interface. This allows for straightforward integration into microcontroller-based designs. Moreover, the device includes an on-chip memory that stores settings, which streamlines the reconfiguration process when power cycling, minimizing setup time for developers.

Another significant advantage of the SI5351A/B/C is its output jitter performance, which is typically below 1 ps, resulting in clean output signals essential for high-speed data communications and precise timing applications. The SI5351’s integration of multiple synthesizer stages contributes to its impressive phase noise characteristics, making it suitable for demanding RF applications.

Additionally, the SI5351 devices offer programmable frequency stepping, allowing users to define custom frequency increments, which is particularly useful in applications requiring precise tuning or modulation. This flexibility, combined with its compact size and simple interface, makes the SI5351A/B/C an ideal choice for engineers seeking a reliable, cost-effective solution for generating clock signals in a myriad of electronic systems.

In summary, Silicon Laboratories SI5351A/B/C provides a robust, low-power solution for high-precision clock generation, characterized by its programmable outputs, low jitter, easy configurability, and broad frequency range, making it an excellent choice for both commercial and industrial applications across various sectors.