5-2018

RF & Wireless
Switchable Oscillators Offer Frequency a la Carte
Euroquartz has launched a new range of
switchable crystal oscillators offering users
the ability to provide four different frequencies.
The new QuikXO HC_JF series oscillators
are available in frequencies from 15
to 2100 MHz with a choice of outputs including
LVCMOS (up to 250 MHz), LVPECL,
LVDS and CML differential. High current
steering logic (HCSL) differential outputs
are available for frequencies up to 700 MHz.
Integrated phase jitter performance of 150 fs
maximum makes these crystal oscillators
particularly suitable for high frequency
applications.
QuikXO HC_JF series crystal oscillators
are available at low cost and can be delivered
in days for prototypes with a choice of
supply voltages – 1.8, 2.5 or 3.3 V – across
the range apart from LVPECL with 2.5 and
3.3 V only. Customers can select any four
frequencies in the range and the oscillator
can switch to each as required, useful in
frequency bus distribution applications on
multi-processor boards where several frequencies
are required for the different processors.
The four chosen frequencies can
all be synchronised from the single crystal
oscillator instead of trying to sequence multiple
clocks to achieve switching in of the
various processors.
Frequency selection is made using two
logic control pads FS0 and FS1 to provide
the four user selectable frequencies with
frequency select timing of 2.5 ms maximum.
Frequency stability specifications of
±25, ±50 and ±100 ppm over both commercial
(-10 to +70 °C) and industrial (-40 to
+85 °C) temperature ranges are available
as standard. Other specifications include
maximum ageing of ±3ppm in first year,
duty cycle of 50% ± 5%, rise times of 0.35
ns maximum and current consumption from
62 to 99 mA typical. RoHS compliant, the
new QuikXO HC_JF crystal oscillators are
housed in industry standard 8-pad, 7 x 5 mm
surface mount packages.
■ Euroquartz, Ltd.
www.euroquartz.co.uk
New EMI Components
Manufacturers of electronic
equipment for Hi-Rel applications
often struggle to meet
stringent EMC and safety
standards. Knowles Precision
Devices (KPD) has a range of
EMI components, under the
SYFER brand, that particularly
appeal to designers in the
medical implantable and space
sectors as well as industrial,
automotive, aerospace and
telecom applications.
The increasing use of SMD
filters over conventional panel
mounted filters has simplified
assembly methods, reduced
production costs and enabled
smaller volumetric efficiencies
to be gained giving a greater
choice of options to the
designer - particularly shorter
lead-times for development
samples.
KPD continues to refine existing
ranges, explore new ones
and bring on board new materials,
like lead free dielectrics.
For example, the SYFER E01
and E07 ranges of feed through
MLCC ‘C’ filters now have
extended working voltages
from 25 to 200 Vdc, and in
certain cases up to 500 Vdc.
This will significantly broaden
the market for these devices.
These surface mount EMI filter
3 terminal chip devices are designed
to offer reduced inductance
compared to conventional
MLCC’s when used in
signal line filtering. The filtered
signal passes through the chip’s
internal electrodes with the
‘noise’ filtered to the grounded
side contacts, resulting in reduced
length noise transmission
paths. Available in C0G/NP0 &
X7R di electrics, in case sizes
0805 to 1812. Current ratings
are 300 mA to 3 A with voltage
ratings of 25 to 200 Vdc (500
Vdc in some case sizes).
Particularly effective in replacing
conventional array filters
in medical implantable devices
is the SYFER E03 (X2Y)
range. Available in case sizes
from 0805 to 2220 these are
integrated passive devices featuring
both common and differential
mode capacitors in a
single MLCC chip. C0G and
X7R dielectric versions are
both available options. X7R
dielectric versions are available
with KPD‘s proven FlexiCap
termination which is strongly
recommended for new designs.
Ideal for both signal and power
lines, and ensuring impressive
EMI filtering performance, is
the SYFER SBSP range of
surface mount pi-filters. With
a size of only a 1206 chip they
offer an unbeatable combination
of size and performance.
Ideal for telecoms, power
supplies and industrial electronic
equipment. The operating
temperature range of -55
to +125 °C ensures they are
also suitable for mil/aerospace
applications. The use of X7R
and C0G ceramic dielectrics
sees capacitance values from
22 pF to 150 nF with a 1 A current
rating. They have working
voltages up to 100 Vdc.
■ Knowles Precision Devices
www.knowlescapacitors.
com
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