Oscillator needs no divider for 4MHz operation

The CX3225SB is the world's first miniature low-frequency quartz crystal unit that oscillates in the 4MHz frequency range.

New from Kyocera, the CX3225SB is the world's first miniature low-frequency quartz crystal unit that oscillates in the 4MHz frequency range.

At one twenty-seventh the size of conventional units, the CX3225SB provides stable frequency sources for applications that require compact size and power savings, such as portable DVDs, handheld game-players, PDAs and cellular handsets.

Previously, when no small quartz crystal unit was available oscillating at this frequency, Kyocera Kinseki divided higher frequencies, such as 16MHz, using ICs, to obtain 4MHz.

However, if small crystal units oscillate at 4MHz directly, the dividing process can be omitted.

Based on this, the CX3225SB reduces the power consumption of the overall device by approximately 30%.

Moreover, the CX3225SB complies with the RoHS Directive, the European Union's Restriction of Certain Hazardous Substances, and is compatible with the reflow profile of lead-free soldering.

Masahiko Goto of the Kyocera Kinseki Engineering Division explains: "We reviewed all designs from the level of crystal fragments used as elements".

"If crystal fragments are made thinner in conventional thickness-shear mode oscillation, the oscillation frequency will increase, so products cannot be made smaller".

"We consequently decided to introduce Lame-mode oscillation, which has yet to find widespread application in the industry".

Lame-mode oscillation possesses a different oscillation pattern from the thickness-shear mode oscillation, which has been the most common approach in crystal units.

"There are many types of oscillation patterns, including face shear, flexture, extensional and thickness shear".

"Considering the two factors of compact size and low frequency, we presumed that the Lame-mode oscillation would be the most appropriate".

"We conducted an analysis using our simulation technology, and concluded that the Lame-mode oscillation is superior to face shear, flexture, and extensional even in frequency temperature characteristics", says Goto.

"This product is not as small as some ceramic oscillators, but it outperforms those ceramic oscillators in accuracy and stability, in frequency tolerance and frequency temperature characteristics at room temperature".

"We hope that this product will enable smaller digital mobile devices and improve performance, as demand is expected to grow in the future".

With cellular handsets and other digital devices becoming increasingly compact, and with ongoing needs for power savings, there has been growing demand for quartz crystal units that support greater needs.

As one of the key components of digital devices, quartz crystal units can make them smaller and reduce the power consumption of batteries by providing support for low frequencies.

As the frequency falls, however, the element normally becomes larger.

At present, there are few quartz crystal units on the market that meet the twin demands of compact size and support for low frequency.

Kyocera Kinseki, a company that specialises in crystal materials and components and is 100% owned by Kyocera, has responded to this demand, applying its advanced technologies in the simulation, etching, and production of small crystal units that have been developed over many years.

The result is the successful development of this miniature low-frequency quartz crystal unit.

This product dramatically reduces capacity to one twenty-seventh compared with the company's conventional product, while oscillating at low frequencies around 4MHz.

Samples of CX3225SB will ship from November.

Mass production is scheduled to commence in April 2006 at Kyocera Kinseki Yamagata on a monthly production basis of 100,000 units.

Back to top