P17E.pdf
2015.12.25
• Please read rating and CAUTION (for storage, operating, rating, soldering, mounting and handling) in this catalog to prevent smoking and/or burning, etc.
• This catalog has only typical specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.
Note
Characteristics and Types of CERALOCK®
RoHS
1
1
®ꢀ
1. General Characteristics of CERALOCK
Ceramic resonators use the mechanical resonance of
piezoelectric ceramics. (Generally, lead zirconium titanate:
PZT.)
The oscillation mode varies with resonant frequency.
The table on the right shows this relationship.
As a resonator device, Crystal Unit is well-known. RC
oscillation circuits and LC oscillation circuits are also used
to produce electrical resonance. The following are the
characteristics of CERALOCK®.
① High stability of oscillation frequency:
ꢁ Oscillation frequency stability is between that of Crystal
Units and LC or RC oscillation circuits.
ꢁ The temperature coefficient of Crystal Units is 10–6/ °C
maximum and approximately 10–3 to 10–4/°C for LC or
RC oscillation circuits. For comparison these, it is 10–5/°C
at –20 to +80°C for ceramic resonators.
Vibration Mode and Frequency Range
Frequency (Hz)
Vibration Mode
1k 10k 100k 1M 10M100M 1G
1
Flexural
mode
2
Length
mode
3
Area
expansion
mode
4
Radius
vibration
5
Shear
thickness
mode
6
Thickness
expansion
mode
7
② Small configuration and light weight:
ꢁ The ceramic resonator is half the size of popular Crystal
Units.
Surface
acoustic
wave
[Note] : ←→show the direction of vibration
③ Low price, non-adjustment:
ꢁ CERALOCK® is mass produced, resulting in low cost and
high stability.
ꢁ Unlike RC or LC circuits, ceramic resonators use
mechanical resonance. This means it is not basically
affected by external circuits or by the fluctuation of the
supply voltage.
ꢁ Highly stable oscillation circuits can therefore be made
without the need of adjustment.
The table briefly describes the characteristics of various
oscillator elements.
Characteristics of Various Oscillator Elements
Oscillation
Long-
term
Adjust-
ment
Frequency
Initial
Name
Symbol
Price
Size
Stability
Tolerance
lower
cost
LC
Big
Required ±2.0%
Required ±2.0%
Fair
Fair
lower
cost
CR
Small
Big
Crystal
Unit
Expen-
sive
Not
±
Excellent
required 0.001%
Ceramic
Resonator
Inexpen-
sive
Not
required
Small
±0.5% Excellent
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