h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 762

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 21 Clock Pulse Generator
External circuitry such as that shown below is recommended around the PLL.
Place oscillation stabilization capacitor C1 and resistor R1 close to the PLLCAP pin, and ensure
that no other signal lines cross this line. Supply the C1 ground from PLLVSS.
Separate PLLVSS from the other VSS lines at the board power supply source, and be sure to insert
bypass capacitors CB close to the pins.
Rev. 5.00 Sep 22, 2005 page 736 of 1136
REJ09B0257-0500
Note: * CB is laminated ceramic capacitors.
Figure 21.5 Points for Attention when Using PLL Oscillation Circuit
Figure 21.4 Example of Incorrect Board Design
Avoid
PLLCAP
PLLV
V
V
CC
SS
SS
C
C
L2
L1
R1: 3 k
Signal A Signal B
CB: 0.1 F *
C1: 470 pF
(Values are preliminary recommended values.)
H8S/2646 Group
XTAL
EXTAL