Datasheet

Electrical Specifications
3.3V Control Timing
MC68HC908LJ24/LK24 — Rev. 2.1 Data Sheet
Freescale Semiconductor Electrical Specifications 441
24.9 3.3V Control Timing
24.10 5V Oscillator Characteristics
Table 24-7. 3.3V Control Timing
Characteristic
(1)
Notes:
1. V
SS
= 0 Vdc; timing shown with respect to 20% V
DD
and 70% V
DD
, unless otherwise noted.
Symbol Min Max Unit
Internal operating frequency
(2)
2. Some modules may require a minimum frequency greater than dc for proper operation; see appropriate table for this
information.
f
OP
—4MHz
RST
input pulse width low
(3)
3. Minimum pulse width reset is guaranteed to be recognized. It is possible for a smaller pulse width to cause a reset.
t
IRL
1.5 — µs
Table 24-8. 5V Oscillator Specifications
Characteristic Symbol Min Typ Max Unit
Internal oscillator clock frequency
f
ICLK
50k
(1)
Notes:
1. Typical value reflect average measurements at midpoint of voltage range, 25 ×C only. See Figure 24-1 for plot.
Hz
External reference clock to OSC1
(2)
2. No more than 10% duty cycle deviation from 50%.
f
OSC
dc — 20M Hz
Crystal reference frequency
(3)
3. Fundamental mode crystals only.
f
XCLK
— 32.768k 4.9152M Hz
Crystal load capacitance
(4)
4. Consult crystal manufacturer’s data.
C
L
———
Crystal fixed capacitance
C
1
—
2 × C
L
(27p)
—F
Crystal tuning capacitance
C
2
—
2 × C
L
(33p)
—F
Feedback bias resistor
R
B
—20M—Ω
Series resistor
(5)
5. Not Required for high frequency crystals.
R
S
—100k—Ω