Clock Jitter Cleaners Generate Frequencies To 1.5 GHz

To enhance performance while reducing bill-of-materials (BOM) cost, a family of clock jitter cleaners features low phase noise and RMS jitter performance: 111 fs from 12 kHz to 20 MHz and a wideband noise floor of 162 dBc/Hz at 184-MHz output. The LMK04800 family comprises the LMK04808, LMK04806, LMK04805, and LMK04803 integrated circuits (ICs). It is optimized for generating different frequencies to 1.5 GHz for clocking analog-to-digital converters (ADCs), digital- to-analog converters (DACs), SerDes, and field-programmable gate arrays (FPGAs).

To increase flexibility and configurability, the family integrates features like holdover, switchover, multiple inputs, digital delay, analog delay, odd/even dividers, and 12 programmable output-format drivers. As a result, clock-architecture complexity is reduced while design engineers gain options for trading off system performance, component count, and cost. In addition, the LMK04800 clock jitter cleaners combine with the firm's high-speed operational amplifiers and ADCs (LMH6554, LMH6517, ADC12D1600, ADC12D1000, and ADC16DV160) to provide a low-noise signal-path system solution. Supplied in 64-pin LLP packages, the LMK04808, LMK04806, LMK04805, and LMK04803 are priced at $9.15 each in 1000-unit quantities.

National Semiconductor Corp., 2900 Semiconductor Dr., Santa Clara, CA 95051; (408) 721-5000,

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