SH7047 Datasheet, PDF (96/764 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTMRISC engine Family/SH7000 Series

A circuitry shown in figure 4.6 is recommended as an external circuitry around the PLL. Place
oscillation stabilization capacitor C1 close to the PLLCAP pin, and ensure that no other signal
lines cross this line. Separate PLLVcL and PLLVss circuit against Vcc and Vss circuit from the
board power supply source, and be sure to insert bypass capacitors CB and CPB close to the pins.
R1: 3kΩ
PLLCAP
C1: 470 pF
PLLV_CL
PLLV_SS
CPB = 0.47 µF^*
V_CC
CB = 0.47 µF^*
V_SS
(Values are recommended values.)
Note: * CB and CPB are laminated ceramic type.
Figure 4.6 Recommended External Circuitry Around the PLL
Electromagnetic waves are radiated from an LSI in operation. This LSI has an electromagnetic
peak in the harmonics band whose primary frequency is determined by the lower frequency
between the system clock (φ) and peripheral clock (Pφ). For example, when φ = 50 MHz and Pφ =
40 MHz, the primary frequency is 40 MHz. If this LSI is used adjacent to a device sensitive to
electromagnetic interference, e.g. FM/VHF band receiver, a printed circuit board of more than
four layers with planes exclusively for system ground is recommended.
Rev. 2.00, 09/04, page 56 of 720