Clock cleaner ICs offer low phase noise performance

National Semiconductor Corp. has released a family of clock jitter cleaners that they claim features the industry's lowest phase noise and rms jitter performance of 111 femtosecond (fs) from 12kHz to 20MHz, and a wideband noise floor of -162dBc/Hz at 184MHz output frequency. This enhances the performance of systems used in wireless and wired communications, test and measurement, medical imaging, software defined radio (SDR) and digital broadcast applications, while reducing overall bill of materials (BOM) cost.

The LMK04800 family, comprised of four ICs—LMK04808, LMK04806, LMK04805 and LMK04803—is optimized for generating different frequencies up to 1.5GHz for clocking ADCs, DACs, SerDes and FPGAs. With integrated features such as holdover, switchover, multiple inputs, digital delay, analog delay, odd/even dividers and 12 programmable output format drivers, the LMK04800 ICs are highly flexible and configurable to support a variety of different architectures while reducing the number of components and design effort required to implement these functions.

This combination of performance and functional integration reduces clock architecture complexity and provides design engineers with multiple options to tradeoff system performance, component count and cost. The LMK04800 clock jitter cleaners combine with National's high-speed op amps and ADCs (LMH6554, LMH6517, ADC12D1600, ADC12D1000, and ADC16DV160) to provide a complete signal-path system solution.

Supplied in 64-pin LLP packages, the LMK04808, LMK04806, LMK04805 and LMK04803 are available now, priced at US$9.15 each in 1,000-unit quantities.