EURO
QUARTZ
Provides up to 15dB reduction in system EMI
‘Drop-in’ replacement for standard clocks
Choice of modulation rate and spread
Miniature package: 7.0mm x 5.0mm x 1.8mm
3EQHM57 Low EMI Oscillator
Page 1 of 2
7 x 5 x 1.8mm SMD - Group 'P' - Low Jitter
In electrical systems the principal cause of electro-
magnetic interference (EMI) is the system clock
oscillator. Traditional methods of 'patching-up' systems
with too high a level of EMI is to use ferrite beads,
filters, ground planes, metal shielding and similar costly
methods, However, the most efficient and economic
method to reduce EMI is to reduce it at source: replace
the system clock ocillator with a low EMI clock oscillator.
Compared with conventional clock oscillators, Spread
Spectrum (Dithered) Oscillators can reduce EMI by as
much as 15dB. The part is a 'drop-in' replacement for a
standard clock oscillator hence there is no requirement
to re-design existing PCBs.
DESCRIPTION
EQHM57 series low EMI oscillators can reduce system EMI by 15dB.
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, operating in the kHz region, makes the
process transparent to the oscillator frequency. There is a choice of
modulation rates and spread to suit application requirements.
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 by the frequency modulation technique. The controlled
modulation process may be applied to the 'down' side of the nominal
frequency (known as
DOWN SPREAD,)
or spread equally either side
of nominal (CENTRE
SPREAD).
Down Spread is preferred if over-
clocking would cause 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
EURO
QUARTZ
3EQHM57 Low EMI Oscillator
13.0MHz to 220MHz
Page 2 of 2
7 x 5 x 1.8mm SMD - Group 'P' - Low Jitter
SPECIFICATION
Model No:
3EQHM57 (Group ‘P’)
Frequency Range:
13.0MHz to 220MHz
Spread Types:
See table below
EMI Reduction*:
EMI Reduction (dB) = 10log("Total%"x"SSC Frequency(MHz)"/0.12)
Modulation Carrier Frequency:
25.3kHz min, 58.6kHz max.
Frequency dependent
Call for details
Output Logic:
CMOS
Input Voltage:
Vdd = +3.3VDC ±5%
Frequency Stability***
Commercial (0~70°C): ±25ppm (Spec. code = ‘A’)
±50ppm (Spec. code = ‘B’)
±100ppm (Spec. code = ‘C’)
Industrial (-40~+85°C):
±25ppm (Spec. code = ‘D’)
±50ppm (Spec. code = ‘E’)
±100ppm (Spec. code = ‘F’)
Output Voltage HIGH ‘1’:
2.4V min. at 80% Vdd
Output Voltage LOW ‘0’:
0.4V max. at 20% Vdd
Rise/fall Times:
1.2ns max,
(frequency dependant)
Load:
15pF
Start-up Time:
2ms typical, 5ms max.
Current Consumption:
25mA typical,
freq. dependant
Duty Cycle:
50%±5% (CL=15pF, 50%Vdd)
Cycle to Cycle Jitter:
±100ps typ. ±150ps max.
Output Impedance:
40 Ohms typical
Static Discharge Voltage:
>2000V (per MIL STD 833)
Storage Temperature:
-65°C to +150°C
Ageing:
±5ppm /year max at Ta=25°C
Packaging:
EIA 16mm tape and reel, 1k per.
Pad 1 Option:
No function available. Do not
electrically connect pad 1.
Notes:
*
EMI reduction is applied to the entire frequency spectrum
**
dBc: with respect to no modulation. Frequency and total %
spread dependant.
***
Frequency Stability parameter excludes modulation.
OUTLINE & DIMENSIONS
ENVIRONMENTAL SPECIFICATION
RoHS Compliance:
Storage Temperature Range:
Humidity:
Hermetic Seal:
Solderability:
Reflow:
Vibration:
Shock:
RoHS compliant and Pb (lead) free
-55° to +125°C
85% RH, 85°C for 48 hours
Leak Rate 2x10
-8
ATM-cm
3
/s max.
MIL-STD-2002F method 208E
260° for 10 seconds
MIL-STD-202F method 204,
35g 50Hz to 2000Hz
MIL-STD-202F method 213B, test
condition: E, 1000g ½ sine wave
SPREAD TYPES and % MODULATION
PART NUMBER CONFIGURATION
DOWN SPREAD
Series designation
Group ‘P’
D0.5
D0.75
-0.5%
-0.75%
-1.25%
-2.0%
-2.5%
-3.0%
-3.5%
-3.75%
CENTRE SPREAD
C0.25
C0.375
C0.625
C1.0
C1.25
C1.5
C1.75
C1.875
±0.25%
±0.375%
±0.625%
±1.0%
±1.25%
±1.5%
±1.75%
±1.875%
3EQHM57-B-32.768P-C0.5
Frequency (MHz)
Frequency Stability Code
‘A’ to ‘F’. See specification above
D1.25
D2.0
D2.5
D3.0
D3.5
D3.75
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
Analog electronics
京公网安备 11010802033920号
EEWORLD
