HD64F3048F16 Datasheet, PDF (659/903 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

EXTAL
Section 19 Clock Pulse Generator
C _L1
XTAL
Rd
C _L2
Figure 19.2 Connection of Crystal Resonator (Example)
If a crystal resonator with a frequency higher than 20 MHz in the case of the 5 V version, or 13
MHz in the case of the 3 V version, is connected, the external load capacitance values in table 19.2
should not exceed 10 [pF]. Also, in order to improve the accuracy of the oscillation frequency, a
thorough study of oscillation matching evaluation, etc., should be carried out when deciding the
circuit constants.
Table 19.1 Damping Resistance Value
Damping Resistance
Value
Frequency f (MHz)
2 2 < f ≤ 4 4 < f ≤ 8 8 < f ≤ 10 10 < f ≤ 13 13 < f ≤ 16 16 < f ≤ 18 18 < f ≤ 25
Rd (Ω) H8/3048B
1 k 500
200
0
0
0
0
0
Group
Note: A crystal resonator between 2 MHz and 25 MHz can be used. If the chip is to be operated
at less than 2 MHz, the on-chip frequency divider should be used. (A crystal resonator of
less than 2 MHz cannot be used.)
Table 19.2 External Capacitance Values
External Capacitance Value
Frequency f (MHz)
C = C (pF)
L1
L2
5 V Version
20 < f ≤ 25
2 ≤ f ≤ 20
10
10 to 22
3 V Version
2 ≤ f ≤ 13
13 < f ≤ 25
10 to 22
10
Rev. 3.00 Sep 27, 2006 page 631 of 872
REJ09B0325-0300