Datasheet

56F8014 Technical Data, Rev. 11
122 Freescale Semiconductor
• PCB trace lengths should be minimal for high-frequency signals
• Consider all device loads as well as parasitic capacitance due to PCB traces when calculating capacitance.
This is especially critical in systems with higher capacitive loads that could create higher transient currents
in the V
DD
and V
SS
circuits.
• Take special care to minimize noise levels on the V
REF
, V
DDA
and V
SSA
pins
• Using separate power planes for V
DD
and V
DDA
and separate ground planes for V
SS
and V
SSA
is
recommended. Connect the separate analog and digital power and ground planes as close as possible to
power supply outputs. If both analog circuit and digital circuit are powered by the same power supply, it is
advisable to connect a small inductor or ferrite bead in serial with both V
DDA
and V
SSA
traces.
• It is highly desirable to physically separate analog components from noisy digital components by ground
planes. Do not place an analog trace in parallel with digital traces. It is also desirable to place an analog
ground trace around an analog signal trace to isolate it from digital traces.
• Because the Flash memory is programmed through the JTAG/EOnCE port, SPI, SCI or I
2
C, the designer
should provide an interface to this port if in-circuit Flash programming is desired.