原标题：IDT 8V49NS0312 12路2.5 GHz时钟发生器解决方案

　　IDT公司的8V49NS0312是FemtoClock® NG 12路时钟发生器:11个差分(LVPECL或LVDS)和1个LVCMOS,提供各种频率配置和输出格式,以优化相位噪音性能.差分输出频率从10.91 MHz到2.5 GHz,LVCMOS频率250MHz,相位抖动小于100fs,集成了OTP非易失性存储器,主要用在如10Gb,40Gb和100Gb以太网系统等通信和数据通信市场.本文介绍了8V49NS0312主要特性,功能框图,应用电路图以及评估板EVK-8V49NS0312主要特性和电路图.

　　The IDT® 8V49NS0312 enables the high-performance timing needed for complex system environments such as those seen in 10, 40 and100 Gigabit Ethernetsystems.

　　The 8V49NS0312 is a flexible Clock Generator with a total of four output dividers: three integer and one that is either integer or fractional. When used with an external crystal, the 8V49NS0312 generates high-performance timing geared towards the communications and datacom markets, especially for applications demanding extremely low phase noise, such as 10, 40 and 100GE. The device is offered in a lead-free 64-VFQFN package and is designed to operate across full industrial temperature range.

　　The 8V49NS0312 provides versatile frequency configurations and output formats and is optimized to deliver excellent phase noise performance. The device delivers an optimum combination of high clock frequency and low phase noise performance, combined with high-power supply noise rejection. Flexibility and ease of programmability allow these devices to be used in a variety of clock trees while reducing engineering effort. The device is programmable through an I2C interface and also supports I2C master capability to allow the register configuration to be read from an external EEPROM. IDT’s Timing Commander™ software tool enables a fast and easy reconfiguration of the devices.

　　8V49NS0312主要特性:

　　Provides a total of 12 outputs: 11 differential (LVPECL or LVDS) and 1 LVCMOS on 3 integer and 1 integer or FracN divider

　　Low phase jitter: < 100 fs RMS Phase Jitter, 12 kHz to 20 MHz

　　Output frequencies from 10.91 MHz up to 2.5 GHz differential, 250 MHz LVCMOS

　　Flexible input options

　　10 MHz to 50 MHz fundamental-mode crystal such as the IDT 603-40-48 or 603-38.88-7

　　Reference input from 5 MHz to 1 GHz

　　Flexibility

　　One Time Programmable (OTP) non-volatile memory

　　Select configurations may be controlled via the use of control input pins without the need for serial port access

　　LVCMOS compatible I2C serial interface gives access to additional configurations either alone or in combination with the control input pins

　　-40℃ to +85℃ ambient operating temperature

　　Packaged in 64-pin VFQFN, lead-free RoHS (6)

　　Supported by IDT Timing Commander Software

　　图.8V49NS0312功能框图

　　8V49NS0312评估板EVK-8V49NS0312

　　The board can be configured through I2C, which offers complete control of the device features, or throughtri-level pin selections which offers the most popular configurations. When the board is connected to a PCrunning IDT Timing Commander Software through USB, the device can be configured and programmed togenerate frequencies with best-in-class performances.

　　The EVK-8V49NS0312 evaluation board kit is a platform that is designed to help the customer evaluate IDT’s 8V49NS0312 FemtoClock® NG 12-output Clock Generator. When the board is connected to a PC running IDT Timing Commander software through USB, the device can be configured and programmed through a graphical interface or through register settings, to generate frequencies with best-in-class performance.

　　评估板EVK-8V49NS0312主要特性:

　　Terminals for input clocks

　　Fully configurable through IDT Timing Commander software

　　Allows access to all output signals

　　图.评估板EVK-8V49NS0312外形图