PORTLAND, Ore. -- Mobius Microsystems Inc. (Sunnyvale, Calif.) today unveils its CMOS Harmonic Oscillator (CHO) technology that eliminates the need for quartz crystals in many applications. By integrating an oscillator onto an ordinary complementary metal oxide semiconductor (CMOS) chip, the company claims to have removed the last moving part from electronics circuitry.
"We are announcing today the most accurate CMOS oscillator that has ever been built," claimed Tunc Cenger, director of marketing at Mobius. "Our CMOS oscillators are not as accurate as quartz, but our CMOS Harmonic Oscillator adds proprietary compensation circuitry that meets the requirements of a wide variety of timing-chip applications."
Quartz crystals, a piezoelectric material, provide a rock-solid mechanical time reference for traditional electronic oscillators by permitting them to sync with its mechanical vibrations. Using a quartz crystal and a phased-locked loop chip, a traditional oscillator can achieve ultra-high accuracy of 25 parts-per-million (PPM) or less. MEMS oscillators follow the same tack, but downsize the quartz-crystal resonator to the size of a microscopic tuning fork. Now, Mobius claims to have eliminated the need for the mechanical reference and PLL altogether, albeit only for applications that can tolerate inaccuracies of 100 parts PPM.
"Mobius is going one step further than MEMS, since its oscillators have no moving parts at all," said contributing analyst Steve Cullen with In-Stat (Scottsdale, Ariz.) "It's an all-CMOS solution, which is tough to beat, but it's not universally applicable, since it's not as stable as quartz crystals."
Mobius has identified multiple high-volume markets for its CHO technology (where 100 PPM is adequate), including providing the timing signals for the serial PCI-Express peripheral bus; for universal serial bus (USB) devices; for serial hard disk drives (S-ATA); for flat-panel displays; and for printers. For each of these applications, switching to a CHO chip means that OEMs can reduce their bills-of-material (BOM) by dropping quartz crystals.
"Mobius has done a good job of identifying high-volume applications that will work well with its CMOS oscillator . . . where a drift of 100 parts per million is no big deal," said Cullen.
Mobius' first commercial part--the MM8511--is pin-compatible replacement with existing Spread Spectrum PLLs. The MM8511, however, does not require users to hook-up a quartz crystal to it.
"[The] MM8511 replaces both a quartz crystal and its phases locked loop, which demonstrates how CHO can be used to build large-scale CMOS functions," said Cenger.
Mobius claims that eventually it wants to stake a claim on more territory now owned by quartz crystals, but admits that CHO is not the right solution to every timing chip problem.
"We believe that in the overall landscape of timing chips there will always be a need for quartz crystals, but we are taking CMOS oscillators where they have never been before in terms of performance," said Cenger.
"In the end, there is probably room in the market for all three technologies--quartz crystal, MEMS and CMOS oscillators," said Cullen. "Quartz will probably remain preferred for high-accuracy applications especially ones that require elaborate temperature stabilization, and there are many applications where the smaller size of MEMS chips will work even better. But for those places that can tolerate relatively lower accuracy, Mobius has got a good shot at offering a very low-cost, no-moving-parts solution."