Datasheet

Section 5 Clock Pulse Generator
REJ09B0465-0300 Rev. 3.00 Page 139 of 982
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
5.7 Usage Notes
5.7.1 Note on Resonators
Resonator characteristics are closely related to board design and should be carefully evaluated by
the user, referring to the examples shown in this section. Resonator circuit parameters will differ
depending on the resonator element, stray capacitance of the PCB, and other factors. Suitable
values should be determined in consultation with the resonator element manufacturer. Design the
circuit so that the resonator element never receives voltages exceeding its maximum rating.
5.7.2 Notes on Board Design
When using a crystal resonator (ceramic resonator), place the resonator and its load capacitors as
close as possible to pins OSC1 and OSC2. Other signal lines should be routed away from the
oscillator circuit to prevent induction from interfering with correct oscillation (see figure 5.19).
C
1
C
2
Signal A Signal BProhibited
PJ0/OSC1
PJ1/OSC2/CLKOUT
Figure 5.19 Example of Incorrect Board Design