mc68hc908jw32 Freescale Semiconductor, Inc, mc68hc908jw32 Datasheet - Page 21

• Manufacturer Part Number: mc68hc908jw32
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

1.7 Pin Function
1.7.1 Power Supply Pins (V
V
Fast signal transitions on MCU pins place high, short-duration current demands on the power supply. To
prevent noise problems, take special care to provide power supply bypassing at the MCU as
shows. Place the C1 bypass capacitor as close to the MCU as possible. Use a high-frequency-response
ceramic capacitor for C1. C2 is an optional bulk current bypass capacitor for use in applications that
require the port pins to source high current levels.
V
1.7.2 Analogy Power Supply (V
V
a decoupling capacitor be connected between the V
as possible.
1.7.3 Internal Voltage Regulator Supply (REG25V, REG33V, and V
VREG25 is the internal core voltage regulator supply. VREG33 and VSS33 are the internal USB voltage
regulator supply.
1.7.4 Oscillator Pins (OSC1 and OSC2)
The OSC1 and OSC2 pins are the connections for the on-chip oscillator circuit.
Freescale Semiconductor
DD
SS
DDPLL
must be grounded for proper MCU operation.
and V
is the internal voltage regulator supply for the CGM module of the device. It is recommended that
SS
are the power supply and ground pins. The MCU operates from a single power supply.
DD
Figure 1-5. Power Supply Bypassing
and V
MC68HC908JW32 Data Sheet, Rev. 5
NOTE: Component values shown
DDPLL
V
DD
V
DD
SS
represent typical applications.
and V
)
MCU
0.1 μF
+
SSPLL
C1
C2
DDPLL
)
and V
SSPLL
V
SS
pins placing it as close to the pins
SS33
)
Pin Function
Figure 1-5
21