CSTCW24M0X53-R0 Datasheet, PDF (8/32 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®}
1. Equivalent Circuit Constants
Fig. 2-1 shows the symbol for a ceramic resonator. The
impedance and phase characteristics measured between
the terminals are shown in Fig. 2-2. This illustrates that
the resonator becomes inductive in the frequency zone
between the frequency Fr (resonant frequency), which
2
provides the minimum impedance, and the frequency Fa
(anti-resonant frequency), which provides the maximum
impedance.
It becomes capacitive in other frequency zones. This
means that the mechanical vibration of a two-terminal
resonator can be replaced equivalently with a
combination of series and parallel resonant circuits
consisting of an inductor : L, a capacitor : C, and a
resistor : R. In the vicinity of the specific frequency
(Refer to Note 1 on page 8), the equivalent circuit can be
expressed as shown in Fig. 2-3.
Fr and Fa frequencies are determined by the
piezoelectric ceramic material and the physical
parameters. The equivalent circuit constants can be
determined from the following formulas. (Refer to Note
2 on page 8)
Fr=1/2π L1C1
Fa=1/2π L1C1C0/(C1+C0)=Fr
Qm=1/2πFrC1R1
1+C1/C0
(Qm : Mechanical Q)
(2-1)
(2-2)
(2-3)
Considering the limited frequency range of FrʽFʽFa,
the impedance is given as Z=Re+jω Le (Leʾ0) as shown
in Fig. 2-4, and CERALOCK^® should work as an
inductance Le (H) having the loss Re (Ω).
Symbol
Impedance between Two Terminals Z=R+jx
(R : Real Component, X : Impedance Component)
Phase φ =tan^-1X/R
Fig. 2-1 Symbol for the Two-Terminal CERALOCK^®
10⁵
10⁴
10³
10²
10
Fr
Fa Frequency (kHz)
90
0
-90
Fig. 2-2 Impedance and Phase Characteristics of CERALOCK^®
L1
C1
R1
C0
R1 : Equivalent Resistance
L1 : Equivalent Inductance
C1 : Equivalent Capacitance
C0 : Parallel Equivalent Capacitance
Fig. 2-3 Electrical Equivalent Circuit of CERALOCK^®
Re
Le
Re : Effective Resistance
Le : Effective Inductance
Fig. 2-4 Equivalent Circuit of CERALOCK^®
in the Frequency Band FrʽFʽFa
6