
5V Oscillator Characteristics
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
301
22.7 5V Oscillator Characteristics
Figure 22-1. RC vs. Frequency
Table 22-6. Oscillator Specications (5V)
Characteristic(1)
1. The oscillator circuit operates at VREG.
Symbol
Min
Typ
Max
Unit
Internal oscillator clock frequency
fICLK
64k
88k(2)
2. Typical value reflect average measurements at midpoint of voltage range, 25
°C only.
104k
Hz
External reference clock to OSC1(3)
3. No more than 10% duty cycle deviation from 50%. The max. frequency is limited by an EMC filter.
fOSC
dc
32M
Hz
Crystal reference frequency
fXTALCLK
30
32.768
100
kHz
Crystal load capacitance(4)
4. Crystal manufacturer value.
CL
—
12.5
—
pF
Crystal xed capacitance(5)
5. Capacitor on OSC1 pin. Does not include parasitic capacitance due to package, pin, and board.
C1
—
15
—pF
Crystal tuning capacitance(6)
6. Capacitor on OSC2 pin. Does not include parasitic capacitance due to package, pin, and board.
C2
—
15
—pF
Feedback bias resistor
RB
110
22
M
Series resistor
RS
100
330
470
k
External RC clock frequency
fRCCLK
7.6M
Hz
RC oscillator external R
REXT
RC oscillator external C
CEXT
—10—
pF
REXT
CEXT
OSC1
VREG
MCU
0
1020
30
4050
8
6
4
2
Resistor, REXT (k)
RC
frequency
,f
RCCLK
(MHz)
CEXT = 10 pF
VDD = 5V, @ 25°C