Handling Notes
RL in the equation of load resonance resistance can be made equal to RS by connecting CL in series, or making it infinite,
which prevents increase in the load resonance resistance.
2
C0
CL
RL R1 1
Vcc
C
5
R
2
C
C
2
C
6
OUT
L
1
R
1
3
R
3
L
2
C
t
C
1
C
4
R
4
1000P
To prevent decrease in the negative resistance, connect the crystal unit to the base of the transistor as in the fundamental
mode crystal oscillation circuit. To use the crystal circuit for both oscillation and multiplication, connect a parallel resonance
circuit having multiplication frequency as resonance frequency to the collector of the transistor.
When selecting circuit constants for zero adjustment range by trimmer capacitor, set the constants to values obtained by
adding approx. 12 to 1510-6 to the room temperature deviation of the crystal unit, centering the value obtained by
measuring the crystal unit with load capacitances in series. (When the room temperature deviation specification of the crystal
unit is 1010-6)
(8) Excitation power of oscillation circuit
Normal operation of crystal units is not assured when excitation power is raised. The allowable excitation power varies
depending on the shape of the crystal unit or the stability of targeted frequency. When highly accurate oscillation is required,
however, it is recommended to use an oscillation circuit with an excitation power of 5 to 50 µW or less. For other cases, refer
to individual relevant crystal units on the pages of the catalog.
(9) Precautions for designing printed circuit board
Be sure to design printed circuit board patterns that connect a crystal unit with other oscillation elements so that the lengths
of such patterns become shortest possible to prevent deterioration of characteristics due to stray capacitances and wiring
inductance. For multi-layer circuit boards, it is important not to wire the ground and other signal patterns right beneath the
oscillation circuit.
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