Recommendation for Hardware Setup 32-Bit FR81S Family
Document No. 002-09375 Rev. *B
10
Below is an example for PCB layer stack:
Figure 6. Example of PCB layer stack
GND
AVcc
Vcc
low speed signals
high speed signals
BAD
crosstalk between
different power supply
planes
GND
Avcc / Vcc
low speed signals
high speed signals
GOOD
separation of
power supply planes for
low EMC requirements
3.5
Power Supply Decoupling
DeCaps for power supply have to be placed within the “current flow”. Otherwise they are senseless, because then their
function become inoperable. The following graphic illustrates this:
Figure 7. Power Supply decoupling caps placement
