CSTCW24M0X53-R0 Datasheet, PDF (10/32 Pages) Murata Manufacturing Co., Ltd. – Ceramic Resonator

P17E.pdf
2012.10.31 ^{Note • 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 because there is no space for detailed specifications. Therefore, please review our product specifications or consult the approval sheet for product specifications before ordering.
2 _{Principles of CERALOCK}^®
2
Notes
(Note 1)
The relationship between the size of the resonator
and the resonant frequency is described as follows.
For example, the frequency doubles if the thickness
doubles, when thickness vibration is used.
The following relationship is obtained when the
length of the resonators is Ὑ, the resonance
frequency is Fr, the speed of sound waves travelling
through piezoelectric ceramics, and the wavelength
is λ.
Fr. Ὑ = Const.
(frequency constant, Fr.t for the thickness)
λ = 2Ὑ
C = Fr.λ = 2Fr. Ὑ
As seen in the above formula, the frequency
constant determines the size of the resonator.
(Note 2)
In Fig. 2-3, when resistance R1 is omitted for
simplification, the impedance Z (ω) between two
terminals is expressed by the following formula.
Z (Т) =
1
jТC0
1
jТC0
(
jТL1+
1
jТC1
)
+
(
jТL1+
1
jТC1
)
=
j
(
ТL1
–
1
ТC1
)
1+
C0
C1
– Т² C0L1
When Т = ¹ = Тr, Z (Тr) =0
L1C1
When Т =
1
= Тa, Z (Тa) = ʿ
C0C1L1/(C0+C1)
Therefore from Т =2πF,
Fr = Тr/2π = _2π
1
L1C1
Fa = Тa/2π = _2π
1
= Fr
C0C1L1/(C0+C1)
1+
C1
C0
Amplitude
Range of
Standing
Wave
L1
C1
(Min.Amplitude) (Max.Amplitude)
Fig. ᶗ
C0
Fig. ᶘ
8