Date post: | 18-Jan-2015 |
Category: |
Business |
Upload: | nicolewindsome |
View: | 294 times |
Download: | 0 times |
slatsyrC
ComponentsMarketplaceSpecialReport:Crystals|March2011
Crystals
Oscillating
with accuracy For almost every electronics application, from microprocessor timing to radio station transmission,
precise frequency control is critical. In order to enable system synchronization and signal
generation, a reference signal or source is generally required for data transfer and communication.
Oscillator, at the heart of most reference sources, produces an output signal without input signal.
By injecting energy composed of noise or the transient power supply response, the start up of
oscillator can be achieved.
Crystal Resonators
• HC series, SMD series, DIP series, VCXO, TCXO
• Rohs, compliant
• No Pb
Anhui Safe Electronics Co Ltd
SMD Quartz Crystal
Gen-Worldly Quartz Crystal Co Ltd
1103 SR_ECMP.indd 46 2011-1-25 15:42:29
Lithium Battery
ComponentsMarketplace
Ceramic Crystal
Resonator (SMD) • All ceramic enclosure
• Frequency available from
3.2768MHz ~ 50MHz
• Initial tolerance up to
±20ppm
• RoHS compliant
• Lead free reflow
solderable
• Package sizes available
from 3.2x2.5mm to
10x4.5mm
Interquip Electronics
Company Ltd
Through the utilization of piezoelectric properties of
various materials, such as ceramic, Rochelle salt, tourmaline
and silicon dioxide (quartz crystals), signals are produced
by resonators and filters. Among these materials, quartz
crystals are frequently used.
Mechanical considerations like vibration, shock and
handling are as important as electrical considerations
for frequency control devices. These devices need to be
handled more carefully than most of the other electronic
components, as they are fragile despite seemingly rugged
packaging.
A feedback network and an amplifier are essential building
blocks for a crystal oscillator. Incorporating a resonator with
an active device and several discrete components, a stand-
alone frequency control device can be produced.
Traditionally speaking, companies specializing in
frequency control products design and manufacture them.
Nowadays, the design and manufacture of crystals and
amplifiers are carried out by separate companies, which
changed the paradigm.
Clock oscillators Being one of the subsets of the general crystal oscillators,
clocks are frequently used to supply frequency timing
to digital circuits and microprocessors. As they are the
simplest of all types of oscillators, they are smaller in size,
consuming less power and more affordable than the
others.
Clocks require only one power supply voltage for operation
and take only a few milliseconds to start up. They can be
found in digital integrated circuits like TTL, CMOS, ECL and
so on. Based on the technology being driven, like 75 MHz
for STTL and 125 MHz for 10k ECL, the frequency range of
1103 SR_ECMP.indd 47 2011-1-25 15:42:37
slatsyrC
ComponentsMarketplaceSpecialReport:Crystals|March2011
Crystals these clocks is initially limited.
Among different crystal cuts that
determine the frequency characteristics
of crystals, AT cut is most commonly
used. Calibration frequency tolerances of
below ∮10ppm can be obtained by clocks.
Depending on the temperature change
of critical resistors, capacitors or inductors,
the oscillator circuit could add to the
crystal drift, although its significance in
frequency variation would be limited.
Voltage controlled
crystal oscillators Voltage controlled crystal oscillators
(VCXOs) enable fine adjustments of
output frequencies through changing the
voltage of control pins of oscillators. They
are suitable for applications that require an
accurate external reference. The oscillator
circuits with a given voltage change
influence the amount of frequency shift.
In most cases, varactor diodes are utilized
to vary the frequency by changing
the capacitance across their terminals
based on the DC voltage across the
same terminals. Only a small range of
frequencies, however, can be varied by
these oscillators due to the limitations
imposed by high Q factor of crystals.
Temperature
compensated crystal oscillator Temperature compensated crystal
oscillator (TCXO) adjusts the frequency
for temperature variation. In order to
compensate for the aging of the crystal
over time, they generally have an outside
adjustment for setting the calibration
frequency periodically. Depending on
the level of accuracy required, the period
between calibrations might range from
Piezoelectric Ceramic
Devices & Quartz Crystals Chequers Electronic (China) Ltd
Crystal oscillators (Model DOC5204)
• High-stability solution OCXO for CDMA, VSAT and
switching applications
• Temperature drift: 0.2ppb
• Ageing: less than 20ppb per year
• Phase noise: -120dBc/Hz at 10Hz
• Ageing: less than 500ppb per year
• Package: metallic through-hole 50mm x 50mm x 38mm
Shenzhen Nearzenith Technologies Co Ltd
1103 SR_ECMP.indd 48 2011-1-25 15:42:46
Battery Charger
ComponentsMarketplace
Crystal Resonators
• HC series, SMD series, DIP series, VCXO, TCXO
• Rohs, compliant
• No Pb
Anhui Safe Electronics Co Ltd
Crystal Resonator
• Compact and thin (3.2× 2.5× 0.65mm typ)
• Both sides supporting structure
advantageous to shock resistance
• Excellent for applications in mobile
communications
• Frequency Range: 12.000MHz~50.000MHz
• Frequency tolerance: ± 30ppm Max
• Storage temperature range: -40ºC to +85ºC
• Load capacitance: 9pF typ
Wuhan HDC Technology Co Ltd
1103 SR_ECMP.indd 49 2011-1-25 15:42:55
slatsyrC
ComponentsMarketplaceSpecialReport:Crystals|March2011
Crystals Quartz Crystal Resonators
(SMD)
• All quartz enclosure • Frequency available from
3.2768MHz ~ 50MHz
• Initial tolerance up to
±20ppm
• RoHS compliant
• Lead free reflow solderable
• Package sizes available from
3.2x2.5mm to 10x4.5mm
Interquip Electronics Company Ltd
Piezoelectric Ceramic
Devices & Quartz Crystals Chequers Electronic (China) Ltd
Crystal oscillators (Model DOC5525)
• Designed for test & measurement,
switches, GPS synchronization
applications, VSAT and DAB
infrastructure
• Cost effective OCXO solution • Temperature drift: less than 200ppb
• Phase noise: -90dBc/Hz at 10Hz
• Ageing: less than 500ppb per year
• Package: 25.4mm x 22mm x 10mm
Shenzhen Nearzenith Technologies Co Ltd
Dip-14 Oscillator Gen-Worldly Quartz Crystal Co Ltd
1103 SR_ECMP.indd 50 2011-1-25 15:43:04
Laptop Battery
ComponentsMarketplace
Dip-8 Oscillator
HC49/U Quartz crystal Gen-Worldly Quartz Crystal Co Ltd
Gen-Worldly Quartz Crystal Co Ltd
High-temp Crystal Oscillator
• Frequency Range: 32.768K-160.000M
• Frequency Stability: 25PPM
• Supply Voltage: 3.3v 5.0v
• Current: 25-90MA
• TS: 10MS
• TR/TF: 10NS
• Operation Temperature: -40ºC~175ºC
• Storage Temperature: -40ºC~70ºC
• Symmetry: 45%-55%
• Output Load: 10TTL/HCMOS
• Dimensions: 20mmx 13.2mmx 5.5mm &13.2mmx 13.2mmx 5.5mm
Wuhan HDC Technology Co Ltd
Crystal oscillators (Model DOC5383)
• Cost-effective SC-cut OCXO • Temperature drift: 10ppb
• Phase noise: -120dBc/Hz at 10Hz
• Ageing: less than 100ppb per year
• Package: metallic through-hole
36mm x 26mm x 18mm
Shenzhen Nearzenith Technologies Co Ltd
once a month to once a year. A TCXO has a larger size,
higher cost and longer start-up time than a clock oscillator.
Oven controlled crystal oscillator Oven controlled crystal oscillator (OCXO) stabilize
frequency variations with an oven. In the instrumentation
market, they are popular timing standards in measurement
equipments such as frequency counters, spectrum
analyzers and network analyzers. Every oven contains
at least a sealed crystal. The oven temperature must be
higher than the maximum ambient temperature expected
in the application in order to maintain control. The cost
and overall size of an OCXO is about 40 times of a clock
oscillator, as it requires periodical calibrations, a separate
power supply for the heater and isolation between
building blocks.
Combination of crystal oscillators Meeting the needs of special applications, combinations
like Temperature Compensated, Voltage Controlled
Crystal Oscillator (TCVCXO) and Oven Controlled,
Voltage Controlled Crystal Oscillator (OCVCXO) have
been developed. These designs are gaining popularity
in applications that previously require several different
oscillators, as various dividers can produce various output
frequencies.
1103 SR_ECMP.indd 51 2011-1-25 15:43:16
slatsyrC
ComponentsMarketplaceSpecialReport:Crystals|March2011
Crystals Anhui Safe Electronics Co Ltd
Address: North of Weiyi Road, Shizishan Economic
Development Zone, Tongling, Anhui, China
Tel: +86 (0562) 2828 608; +86 (0562) 2828 238
Fax: +86 (0562) 2828 708; +86 (0562) 2855 972
E-mail: [email protected]
Homepage: www.anhuisafe.com
Chequers Electronic (China) Ltd
Address: Room 1101-3, Mongkok Commercial Centre, 16
Argyle Street, Mongkok, Kowloon, Hong Kong
Tel: +852 2391 6725
Fax: +852 2789 3205
E-mail: [email protected]
Homepage: www.chequers-electronic.com
Gen-Worldly Quartz Crystal Co Ltd
Address: Unit 403-404, 4/F, Sun Ling Plaza, 30 On Kui
Street, On Lok Tsuen, Industrial Area, Fanling, New
Territories, Hong Kong
Tel: +852 2675 8976
Fax: +852 2675 4792
E-mail: [email protected]
Homepage: www.gen-worldly.com.hk
CONTACT INFORMATION Interquip Electronics Company Ltd
Address: Flat A, 9/F, On Shing Industrial Building, 2-16
Wo Liu Hang Road, Fotan, New Territories, Hong Kong
Tel: +852 2413 5515
Fax: +852 2413 7053
E-mail: [email protected]
Homepage: www.interquip.com
Shenzhen Nearzenith Technologies Co Ltd
Address: 5/F, 51Building, 5 QiongYu Road, High-tech
Industrial Park, Nanshan District, Shenzhen, China
Tel: +86 (755) 8610 0308; +86 (755) 8610 0942
Fax: +86 (755) 8610 1078
E-mail: [email protected]
Homepage: www.nearzenith.com
Wuhan HDC Technology Co Ltd
Address: International Business Center (3rd), Jinfeng
Building A305, Donghu Hi-Tech Development Zone,
Wuhan, Hubei, China
Tel: +86 (27) 8774 5207
Fax: +86 (27) 8759 2096
E-mail: [email protected]
Homepage: www.wuhanhdc.com
1103 SR_ECMP.indd 52 2011-1-25 15:43:19