Regulator Power Supply Configuration (VREG)
V
and V
are the power supply and ground pins for the analog circuits of the MCU. These pins
DDA
SSA
should be decoupled as per the digital power supply pins.
MCU
V
V
V
V
SSA
DD
SS
DDA
C1(a)
0.1 µF
C1(b)
0.1 µF
+
+
C2(a)
C2(b)
V
V
DD
DD
NOTE: Component values shown represent typical applications.
Figure 1-5. Power Supply Bypassing
1.7 Regulator Power Supply Configuration (VREG)
V
V
is the output from the on-chip regulator. All internal logics, except for the I/O pads, are powered by
REG
REG
output. V
requires an external ceramic bypass capacitor of 100 nF as Figure 1-6 shows. Place
REG
the bypass capacitor as close to the V
pin as possible.
REG
MCU
V
V
SS
REG
C
VREGBYPASS
100 nF
Figure 1-6. Regulator Power Supply Bypassing
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
27
FREESCALE [ Freescale ]
