Datasheet

MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
216 Electrical Specifications MOTOROLA
Electrical Specifications
NON-DISCLOSURE AGREEMENT REQUIRED
18.8 5-V Oscillator Characteristics
Figure 18-1. RC versus Frequency (5 Volts @ 25°C)
Characteristic Symbol Min Typ Max Unit
Internal oscillator frequency
f
INTCLK
— 12.8 — MHz
Crystal frequency, XTALCLK
f
OSCXCLK
1 — 32 MHz
RC oscillator frequency, RCCLK
f
RCCLK
2 — 12 MHz
External clock reference frequency
(1)
1. No more than 10% duty cycle deviation from 50%.
f
OSCXCLK
dc — 32 MHz
Crystal load capacitance
(2)
2. Consult crystal vendor data sheet.
C
L
————
Crystal fixed capacitance
(2)
C
1
—
2 x C
L
——
Crystal tuning capacitance
(2)
C
2
—
2 x C
L
——
Feedback bias resistor
R
B
— 10 — MΩ
Series resistor
(2), (3)
3. Not required for high frequency crystals
R
S
————
RC oscillator external resistor
R
EXT
See Figure 18-1 —
0
01020304050
14
12
10
8
6
4
2
Resistor, R
EXT
(kΩ)
RC FREQUENCY, f
RCCLK
(MHz)
R
EXT
OSC1
V
DD
MCU
5 V @ 25°C