Si5345-44-42-D-RM
Rev. 1.0
9
1. Scope
This Family Reference Manual is intended to provide system, PCB design, signal integrity, and software engineers
the necessary technical information to successfully use the Si5345/44/42 devices in end applications. The official
device specifications can be found in the Si5345/44/42 data sheets.
1.1. Related Documents
Si5345/44/42 Data Sheet
Si5345/44/42 Device Errata
Si5345/44/42-EVB User Guide
2. Overview
The Si5345/44/42 jitter attenuating clock multipliers combine 4th generation DSPLL and MultiSynth™ technologies
to enable any-frequency clock generation for applications that require the highest level of jitter performance. These
devices are programmable via a serial interface with in-circuit programmable non-volatile memory (NVM) ensuring
power up with a known frequency configuration. Free-run, synchronous, and holdover modes of operation are
supported offering both automatic and manual input clock switching. The loop filter is fully integrated on-chip
eliminating the risk of potential noise coupling associated with discrete solutions. Further, the jitter attenuation
bandwidth is digitally programmable providing jitter performance optimization at the application level.
These devices are capable of generating any combination of output frequency from any input frequency within the
specified input and output range.
2.1. Work Flow Expectations with ClockBuilder Pro™ and the Register Map
This reference manual is to be used to describe all the functions and features of the parts in the product family with
register map details on how to implement them. It is important to understand that the intent is for customers to use
the
ClockBuilder Pro software
to provide the initial configuration for the device. Although the register map is
documented, all the details of the algorithms to implement a valid frequency plan are fairly complex and are beyond
the scope of this document. Real-time changes to the frequency plan and other operating settings are supported
by the devices. However, describing all the possible changes is not a primary purpose of this document. Refer to
Applications Notes and
Knowledge Base
article links within the ClockBuilder Pro GUI for information on how to
implement the most common, real-time frequency plan changes.
The primary purpose of the software is that it saves having to understand all the complexities of the device. The
software abstracts the details from the user to allow focus on the high level input and output configuration, making
it intuitive to understand and configure for the end application. The software walks the user through each step, with
explanations about each configuration step in the process to explain the different options available. The software
will restrict the user from entering an invalid combination of selections. The final configuration settings can be
saved, written to an EVB and a custom part number can be created for customers who prefer to order a factory
preprogrammed device. The final register maps can be exported to text files, and comparisons can be done by
viewing the settings in the register map described in this document.
2.2. Family Product Comparison
Table 1 lists a comparison of the different family members.
Table 1. Product Selection Guide
Part Number
Number of Inputs Number of MultiSynths Number of Outputs
Package Type
Si5342
4
2
2
44-QFN
Si5344
4
4
4
44-QFN
Si5345
4
5
10
64-QFN