Datasheet

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 Specifications (5V)
Characteristic
(1)
1. The oscillator circuit operates at V
REG
.
Symbol Min Typ Max Unit
Internal oscillator clock frequency
f
ICLK
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.
f
OSC
dc 32M Hz
Crystal reference frequency
f
XTALCLK
30 32.768 100 kHz
Crystal load capacitance
(4)
4. Crystal manufacturer value.
C
L
— 12.5 — pF
Crystal fixed capacitance
(5)
5. Capacitor on OSC1 pin. Does not include parasitic capacitance due to package, pin, and board.
C
1
—
15
—pF
Crystal tuning capacitance
(6)
6. Capacitor on OSC2 pin. Does not include parasitic capacitance due to package, pin, and board.
C
2
—
15
—pF
Feedback bias resistor
R
B
11022MΩ
Series resistor
R
S
100 330 470 kΩ
External RC clock frequency
f
RCCLK
7.6M Hz
RC oscillator external R
R
EXT
See Figure 22-1 Ω
RC oscillator external C
C
EXT
—10—pF
R
EXT
C
EXT
OSC1
V
REG
MCU
0
0 1020304050
8
6
4
2
Resistor, R
EXT
(kΩ)
RC frequency, f
RCCLK
(MHz)
C
EXT
= 10 pF
V
DD
= 5V, @ 25°C