EQHM14 Group ‘R’ Low EMI Oscillators
14 pin Dual-in-Line Spread Spectrum Clock Ocillator
Page 1 of 3
DESCRIPTION
EQHM14R series low EMI oscillators can reduce system EMI by 12dB.
The principal cause of EMI problems is the system
The oscillators are a ‘drop-in’ replacement for standard oscillators.
EMI reduction is achieved by the use of Spread Spectrum Technology
whereby the mode energy is spread over a wider bandwidth. The
modulation carrier frequency in the kHz region makes the process
transparent to the oscillator frequency. There is a choice of
modulation rates and spread.
clock. Therefore, rather than patch the problem
with ferrite beads, filters, ground planes and
metal shielding the most efficient and economic
method of EMI reduction is to use a low EMI clock
oscillator.
Compared with conventional clock oscillators
3EQHM14R series Spread Spectrum (Dithered)
Oscillators can reduce RMI by as much as 12dB.
The part is a 'drop-in' replacement for a standard
14 pin DIL clock oscillator hence there is no
requirement to re-design existing PCBs.
SPREAD SPECTRUM TECHNOLOGY
Unlike a conventional clock oscillator, in a Spread Spectrum Clock
Oscillator the mode energy is spread over a wider bandwidth. This is
achieved resulting from the frequency modulation technique. The
controlled modulation process may be on all on one side of the
nominal frequency (known as DOWN SPREAD,) or spread equally
either side of nominal (CENTRE SPREAD). Down Spread is preferred
is over-clocking would be a problem to the system.
APPLICATIONS
Printers, Multiple Function Printers (MPCs)
Digital Copiers; PDAs
Networking: LAN/WAN; Routers
Storage Systems (CD-ROM, VCD, DVD, HDD)
Scanners; Modems; Projectors
Embedded Systems
Musical Instruments
Automotive: GPS car navigation systems
LCD PC Monitors; LSD TVs
ADSL; PCMCIA
Still Digital Cameras (SDCs)
MODULATION TYPES - EXAMPLES
Output amplitude (dB) vs. frequency span (MHz)
EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE
Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info@euroquartz.co.uk
www.euroquartz.co.uk