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Updated: October 14th, 2008 10:03 AM CDT

National Semiconductor's New Clock Jitter Cleaners Eliminate Need for VCXO Modules

via PRNewswire

These devices feature dual redundant inputs, five differential outputs and an optional default-clock upon power-up. The input block is equipped with loss of signal detection and automatic or manual selection of the reference clock. Each clock output pair consists of a programmable divider, a phase synchronization circuit, a programmable delay and either a low-voltage differential signaling (LVDS), low-voltage positive-emitter-coupled logic (LVPECL) or low-voltage CMOS (LVCMOS) output driver. The LVPECL and LVDS outputs support clock rates up to 1080 MHz, while the LVCMOS outputs reach up to 250 MHz. The default-clock is available on CLKout2 and it can be used to provide an initial clock for the field-programmable gate array (FPGA) or the microcontroller that programs the clock jitter cleaner during the system power-up sequence.

National's LMK04000 precision clock conditioners are supplied in 48-pin LLP(R) packages. National fabricates these products on its proprietary BiCMOS8 process technology in its South Portland, Maine , facility. This state-of-the- art silicon germanium process enables the devices to achieve the lowest jitter and power performance in the industry.

Pricing and Availability

The LMK04011B, LMK04031B and LMK04033B are available now and the LMK04000B, LMK04001B are sampling now with production volumes expected in the first quarter of 2009. All devices are priced at $14.50 each in 1,000-unit quantities. For more information on these precision clock conditioners, or to order samples and an evaluation board, visit,,, and

National's clock design tool simplifies design, analysis and parts selection for a wide variety of applications. To explore this new design tool, visit

About National's Communications Infrastructure Solutions

National Semiconductor's communications infrastructure solutions optimize system efficiency, increase power density and deliver robust system performance. Its PowerWise(R) subsystem reference designs solve energy- efficiency problems at an architectural level in a small footprint, thereby reducing cooling requirements while delivering superior performance. National's reference designs and solutions address the specific needs of wired data centers, wireless base stations and merchant power supply applications.

About National Semiconductor

National Semiconductor creates energy-efficient analog and mixed-signal semiconductors. Its PowerWise(R) products enable systems that consume less power, extend battery life and generate less heat. Headquartered in Santa Clara, Calif. , National reported sales of $1.89 billion for fiscal 2008 which ended May 25, 2008 . Additional company and product information is available at

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