Design Considerations
Mobius Microsystems’ CMOS Harmonic Oscillator™ (CHO) is a simple, robust and reliable frequency reference for Multi-Purpose Printers. CHO products replace the commonly used microcontroller, USB, PCI, and display crystals and crystal oscillators to simplify system design, reduce start-up latency and failure rates. The devices are built in standard CMOS process, and assembled in low profile plastic packages to support thin designs. A single CHO device can generate multiple frequencies, replacing many crystals that are needed on a printer system.

Spread Spectrum Clocking

Spread Spectrum Clocking to Lower EMI

With its CHO technology, Mobius Microsystems offers a powerful tool to lower EMI. The MM8511 product builds upon the standard Spread Spectrum Clock Generation (SSCG) technique, by far the most effective and most preferred method to control EMI. Unlike conventional SSCG implementations, however, the MM8511 CHO replaces both the quartz crystal and the PLL ICs with a monolithic CMOS die, generating Spread Spectrum Clocks without the need for an external resonator. The elimination of the quartz crystal improves reliability, eliminates bulky packages from the system and lowers BOM cost. The elimination of the PLL improves performance by reducing clock jitter, and lowering phase noise and power consumption. The MM8511 supports common TV frequencies, and features selectable frequency spread percentages and modulation rates.