EMI Reducing Spread Spectrum Clock Oscillators (SSXOs)
18HM Series (+1.8 V Supply Voltage)
Group “F”
Features:
◘
Reduces Electromagnetic Interference by approx. -12dB
◘
Drop-In Replacement for Conventional Oscillators
◘
No Need to Re-Spin the Board or Solder Pad Layout
◘
Operates with a +1.8V Supply Voltage
◘
RoHS Compliant & Lead - Free
◘
3.2 x 2.5, 5.0 x 3.2 or 5.0 x 7.0mm Package Sizes
◘
Save Money & Time to Market
MERCURY
Since 1973
18HM53
18HM572
18HM32
Applications:
◘
Printers; Multiple function printers (MPCs)
◘
Digital copiers; PDAs
◘
Networking; LAN / WAN; Routers
◘
Storage systems
(CD-ROM,
VCD, DVD & HDD)
◘
Scanner; Modems; Projectors
◘
Hand-held ID Readers
◘
Embedded systems;
◘
Automotive; GPS Navigation Systems
◘
LCD PC Monitors / LCD TVs
◘
ADSL; PCMCIA
◘
Still Digital Cameras (SDCs)
◘
Medical Devices
Spread Spectrum Crystal Oscillator (SSXO):
Unlike the conventional clock, the mode
energy of a spread spectrum clock is spread
(distributed) over a wider bandwidth between
two pre-defined frequency boundaries by the
frequency modulation
technique. The
modulation carrier frequency is in the KHz
range which makes the modulation process
transparent to the oscillator frequency. This
controlled modulation process can be on all
of one side of the nominal frequency (down
spread),
which is preferred if system over-
clocking is a concern, or 50% up and 50%
down (center
spread).
Modulation Types
DOWN SPREAD or CENTER SPREAD
Down spread “D”.
“D1” as an example
Center spread “C”.
“C0.5” as an example
Output amplitude (dB) vs frequency span (MHz)
dB
Conventional
Clock
dB
EMI reduction
Conventional
Clock
EMI reduction
Spread
spectrum
clock
fo - (fo*1%)
fc
Frequency
fo - (fo*0.5%)
fo=fc
fo+(fo*0.5%)
42 MHz non-SSC vs SSC at Center Spread 0.25%:
No modulation
(non-SSXO)
-9.9 dB
Center spread
0.25% (C0.25)
-22.8 dB
12.3 dB
EMI
reduction
Taiwan: TEL (886)-2-2406-2779, FAX (886)-2-2496-0769, e-mail:
sales-tw@mercury-crystal.com
U.S.A.: TEL (1)-909-466-0427, FAX (1)-909-466-0762, e-mail:
sales-us@mercury-crystal.com
MERCURY
Page 1 of 5
Oct. 11. 2012
Rev. 0
MERCURY
www.mercury-crystal.com
MERCURY [ MERCURY UNITED ELECTRONICS INC ]
