Ceramic Resonator Design Notice

Operating Temperature Ranges:

The resonators should not be operated beyond the Operating Temperature Range specified in the catalog.

Changes/Drifts in Oscillating Frequency:

Oscillating frequency may drift depending upon the controlling IC and/or external capacitors C1 and C2 used in the circuit design.
Direct standard resonator is adjusted with our standard measuring circuit. There could be slight shift in frequency other types of IC are used. When you require exact oscillation frequency in your application, we can adjust it with your specified circuit on request.

Fail-Safe Design for Equipment:

When using The resonators, it is recommended that you build a protective failsafe circuit into your design to prevent equipment damage in the event that the resonator malfunctions or fails.

Abnormal Oscillation:

The resonators are always accompanied by spurious resonances. Spurious oscillations or stoppage of oscillation may occur depending on the circuit design (IC used, frequency characteristics of the IC, supply voltage etc.) and/or environmental conditions. These factors should be taken into consideration when designing the circuit.

Stray Capacitance:

Stray capacitances and insulation resistances on printed circuit boards may cause abnormal oscillation or stoppage of oscillation. These factors should be taken into consideration when designing the circuit.

Overvoltage Spikes & Electrostatic Discharges:

Voltage spikes and electrostatic discharges may cause damage/malfunction or failures of the resonators.

Abnormal Mechanical Stresses:

Abnormal or excess mechanical stresses such as vibration or shock should be avoided when handling or storing resonators to prevent damage and cracking.

Surface Mounting Consideration:

In automated mounting of The resonators on printed circuit boards, any bending, expanding and pulling forces or shocks to the resonator should be kept to a minimum to prevent electrical failures and/or mechanical damage to the devices.

Prohibited Applications

  • Flow Soldering should not be used to solder resonators.
  • Please do not apply excess mechanical stress to the component and lead terminals at soldering.
  • Ultrasonic Cleaning and Ultrasonic Welding should not be used on resonators to avoid possible damage.
  • Avoid washing in water because it could deteriorate the resonator's performance characteristics.
  • Avoid resin coating or potting for humidity protection because it could deteriorate the resonator's performance characteristics.

Crystal VS Ceramics

The majority of clock sources for microcontrollers can be grouped into two types: those based on mechanical resonant devices, such as crystals and ceramics, and those based on electrical phase-shift circuits such as RC (resistor, capacitor) oscillators. Ceramic and crystal resonator-based oscillators (mechanical) typically provide very high initial accuracy and a moderately low temperature coefficient.

Power consumption is another important consideration of oscillator selection. The power consumption of discrete component crystal-oscillator circuits is primarily determined by the feedback-amplifier supply current and by the in-circuit capacitance values used. The power consumption of amplifiers fabricated in CMOS is largely proportional to the operating frequency and can be expressed as a power-dissipation capacitance value.

Ceramic circuits typically specify larger load capacitance values than crystal circuits, and draw still more current than the crystal circuit using the same amplifier.

Advantage of Quartz Crystal

  • Good Frequency Accuracy and Good Stability Over Temperature.

Advantage of Ceramics

  • Cost Saving:
    Lower cost than crystal resonators.

  • Smaller Package Size:
    Miniaturized packaging technology results in very small mainstream packages. Built-in load capacitors are included in same miniature package.

  • Quicker Rise Up of Oscillation:
    Rise time is generally approx. 1/102 of a crystal resonator, significantly faster startup possible.

  • Drive Level Free Circuit Design:
    Due to better holding method of the ceramic element, drive level is not a concern for piezoelectric type resonators.

  • Variety of Characteristics:
    It is possible to control the material (type and amount ) used to make the ceramic material, allowing for various characteristics to be achieve.

  • Overtone Oscillation with No Tank:
    Materials used to make a ceramic material that naturally suppresses its own fundamental response and allows the third overtone response to be used as the oscillation frequency, without addition external tank circuit.

Replace the Crystal?

Piezoelectric resonators provide an attractive alternative to quartz crystals for oscillation frequency stabilization in many applications. Their low cost, mechanical ruggedness and small size often outweigh the reduced precision to which frequencies can be controlled, when compared to quartz devices. Direct resonators are now available in surface mountable packages suitable for automated production processes.

Reducing cost is a key issue for any existing or new design. A popular avenue for cost reduction is replacing a crystal resonator with a ceramics, when possible.

The most important factor for this replacement is frequency tolerance. If your design can accept the looser frequency tolerance of a piezoelectric resonator, then you can gain the benefits offered by a modern ceramic resonator.

Besides cost reduction, ceramics offer impressive size reductions and included two built-in load capacitors. This allows for smaller PCB area to be used and less time in part placement (one part verse three with a crystal).

Direct Electronics Cuts Resonator Size and Cost

Direct's Resonators are made of high stability piezoelectric ceramics that function as a mechanical resonator. This device has been developed to function as a reference signal generator. The frequency is primarily adjusted by the size and thickness of the ceramic element. With the advance of the IC technology, various equipment may be controlled by a single LSI (Large-Scale Integration) integrated circuit, such as the one-chip microprocessor.

Resonator can be used as the timing element in most microprocessor based equipment. In the future, more and more applications will use ceramic resonator because of its high stability non-adjustment performance, miniature size and cost savings.

Typical applications include TVs, VCRs, remote controls and toys, voice synthesizers, automotive electronic devices, copiers, telephones, cameras, communication equipment.

Direct offers a full range of industry standard through hole and surface mount resonators both with and without internal capacitors. For standard Operating Temperatures (-20°C to 80°C), and for Automotive applications (-40°C to +125°C), with a wide range of frequencies and frequency stability options. Additionally, Direct Application Engineering and Design capabilities allow for custom design and characterization requirements that meet the demands of most applications.

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