mc908jl16 Freescale Semiconductor, Inc, mc908jl16 Datasheet - Page 207

• Manufacturer Part Number: mc908jl16
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

17.7 5-V Oscillator Characteristics
Freescale Semiconductor
Internal oscillator clock frequency
External reference clock to OSC1
Crystal reference frequency
Crystal load capacitance
Crystal fixed capacitance
Crystal tuning capacitance
Feedback bias resistor
Series resistor
External RC clock frequency
RC oscillator external R
RC oscillator external C
1. Typical value reflect average measurements at midpoint of voltage range, 25 °C only. See
2. No more than 10% duty cycle deviation from 50%.
3. Use fundamental mode only, do not use overtone crystals or overtone ceramic resonators.
4. Due to variations in electrical properties of external components such as, ESR and Load Capacitance, operation above
5. Consult crystal vendor data sheet.
f
f
f
XTALCLK
XTALCLK
XTALCLK
16 MHz is not guaranteed for all crystals or ceramic resonators. Operation above 16 MHz requires that a Negative Resis-
tance Margin (NRM) characterization and component optimization be performed by the crystal or ceramic resonator vendor
for every different type of crystal or ceramic resonator which will be used. This characterization and optimization must be
performed at the extremes of voltage and temperature which will be applied to the microcontroller in the application. The
NRM must meet or exceed 10x the maximum ESR of the crystal or ceramic resonator for acceptable performance.
14
12
10
8
6
4
2
0
= 1MHz
= 4MHz
= 8MHz to 32MHz
0
(3)
Characteristic
(5)
(3)
10
(3)
(3)(4)
(2)
Figure 17-2. RC vs. Frequency (5V @25°C)
Table 17-6. Oscillator Specifications (5V)
Resistor, R
20
MC68HC908JL16 Data Sheet, Rev. 1.1
EXT
(kΩ)
30
f
Symbol
XTALCLK
f
RCCLK
R
C
f
f
ICLK
OSC
R
R
C
C
C
EXT
EXT
B
S
L
1
2
C
5V @ 25°C
EXT
= 10 pF
40
Min
1M
2M
dc
—
—
—
—
—
—
—
—
See
50
10 MΩ
Figure 17-2
2 × C
2 × C
50k
Typ
—
—
—
20
10
—
10
0
(1)
V
L
L
DD
5-V Oscillator Characteristics
Figure 17-4
R
EXT
Max
32M
32M
12M
—
—
—
—
—
—
—
—
OSC1
for plot.
MCU
C
EXT
Unit
Hz
Hz
Hz
kΩ
kΩ
kΩ
Hz
pF
Ω
207