MC68HC908JG16 Datasheet, PDF (34/324 Pages) Motorola, Inc – Microcontrollers

General Description
Place the bypass capacitors as close to the MCU power pins as
possible. Use high-frequency-response ceramic capacitors for C_BYPASS.
C_BULK are optional bulk current bypass capacitors for use in applications
that require the port pins to source high current levels.
MCU
V_DD
V_SS
C_BYPASS
0.1 µF
+
C_BULK
V_DD
NOTE: Values shown are typical values.
Figure 1-3. Power Supply Bypassing
1.6.2 Voltage Regulator Output Pin (V_REG)
V_REG is the 3.3V output of the on-chip voltage regulator. V_REG is used
internally for the MCU operation and the USB data driver. It is also used
to supply the voltage for the external pullup resistor required on the
USB’s D– line. The V_REG pin requires an external bulk capacitor 4.7µF
or larger and a 0.1µF ceramic bypass capacitor as Figure 1-4 shows.
Place the bypass capacitors as close to the V_REG pin as possible.
V_REG
MCU
V_SS
Technical Data
34
C_REGBYPASS
0.1 µF
+
C_REGBULK
> 4.7 µF
Figure 1-4. Regulator Supply Capacitor Configuration
General Description
MC68HC908JG16 — Rev. 1.1
Freescale Semiconductor