Texas Instruments has introduced an integrated clock generator featuring the jitter performance. The National LMK03806 features high-frequency VCO and programmable output dividers to simplify timing design in wired and optical communications line cards by simultaneously synthesising seven independent frequencies on 14 outputs. With an output frequency that spans 2.37MHz to 2.6GHz, the clock generator provides clocking support for all of the components on a typical line card, says the company.
The clock generator provides sub-50fs rms jitter at 312.5MHz output frequency to enhance bit error rate and carrier-to-noise ratio performance. It features programmable LVDS, LVPECL (low-voltage positive emitter-coupled logic) and LVCMOS in which each output clock is independently configurable, eliminating the need for level translators and fanout buffers, claims the company. The clock generator also features a crystal interface to generate multiple clocks.
The companion LMK00301 differential fanout buffer and level translator accepts a single-ended, differential or crystal input, and produces 10 additional buffered copies of the input clocks of up to 3GHz in LVDS, LVPECL or HCSL format. The translator features good jitter performance, generating 51fs rms jitter at 156.25MHz, and less than 30fs rms at 312.5MHz output frequency when paired with the clock generator, says the company.
The clock generator and translator clocking ICs can be combined with the company's TMS320C6748 DSP and TMS320C66x multicore DSPs to offer a signal-chain solution. The clock generator is available in a 9x9mm, 64pin LLP package and the translator is housed in a 7x7mm, 48pin LLP package.
