Spread spectrum oscillators for reducing EMI emissions

12-08-2021 | Saelig | Passives

Saelig Company now offers the Euroquarz 18EQHM32 series of oscillators that can decrease overall EMI issues in electronic equipment by subtly modifying the system clock oscillator centre frequency and distributing any EMI issues across a wider bandwidth. The new series are intended as drop-in replacements for standard clock oscillators and are aimed at PCBs that may have failed compliance testing by exceeding EMI thresholds. Exchanging the master clock component to an 18EQHM32 oscillator can instantly reduce system EMI by 12dB (typical) and circumvents the cost of redesigning an existing PCB. EMI threshold reduction is accomplished utilising Spread Spectrum Technology, whereby emitted energy is subtly modulated across a wider bandwidth. Centre frequency modulation by a few kilohertz may be applied below, centred, or above the nominal frequency.


These oscillators provide superior jitter performance with cycle-to-cycle jitter of ±100ps when compared to many standard oscillators. Contained in standard 3.2mm x 2.5mm x 1mm surface-mount package, the oscillators are form/fit/function replacements for standard 1.8V oscillators, allowing engineers to make an instant improvement in EMI performance. Other voltage versions are also provided.


Specifications for oscillators include a frequency range from 12.5MHz to 42MHz, a selection of spread types, centre frequency modulation of up to 2%, and a resultant EMI improvement of as much as -18dB depending on spread type. Frequency stability characteristics are as low as ±25ppm across commercial (0C to 70C) and industrial (-40C to +85C) temperature ranges.


The series oscillators are RoHS compliant and are excellent for a broad range of non-time-critical applications, including PDAs, multi-function printers, digital copiers, networking, LAN/WAN storage, computer storage systems (CD-ROM, VCD, DVD, HDD), scanners, projectors, modems, embedded systems, medical equipment, automotive electronics, GPS car navigation systems, LCD monitors and TVs, and digital cameras.

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