Spread-spectrum clock source uses active CMOS circuitry, replaces crystal, PLL

Sunnyvale, Calif—Using patented CMOS Harmonic Oscillator (CHO) technology, a frequency/clock source from Mobius Microsystems Inc. provides accurate, stable clocking with spread-spectrum capability, in a self-contained package and without external resonator (crystal or MEMS), PLL, or passives.

The initial version of the MM8511 integrated clock generator provides outputs from 10 to 100 MHz, with spread-spectrum modulation span of zero to six percent; EMI reduction ranges up to 15 dB. Fabricated using standard CMOS, and available either standalone or suitable for incorporation as IP into a larger IC, the device reduces BOM cost and board footprint due to its self-contained operation. The units meet USB, S-ATA, and PCIe timing requirements for accuracy, stability, phase noise, and jitter, and are suitable for other applications as well.

The monolithic topology of the CHO includes an RF LC GHz resonator at its core. In addition, it incorporates a 96-bit non-volatile memory block for factory calibration and trim, frequency lock loop (FLL, similar to a PLL) for frequency and spread-spectrum programmability, output buffer, and active analog-compensation circuitry.

The 3.3 V IC typically dissipates between 12 and 14 mA. The device is pin- and footprint-compatible with industry-standard PLL/crystal-based oscillators, to simplify BOM substitution and layout revisions. It is available in 8-lead 3×3 mm DFN, 1.6×1.6 mm chip-scale, and 3×6.4 mm TSSOP packages. —Bill Schweber

Pricing:$1.35 each, in 1000-piece quantities
Availability: May availability

Mobius Microsystems Inc. , 1-408-739-5400, www.mobiusmicro.com