Datasheet

Electrical Specifications
MC68HC908QY/QT Family Data Sheet, Rev. 6
154 Freescale Semiconductor
16.8 5-V Oscillator Characteristics
Figure 16-4. RC versus Frequency (5 Volts @ 25•C)
Characteristic Symbol Min Typ Max Unit
Internal oscillator frequency
(1)
1. Bus frequency, f
OP
, is oscillator frequency divided by 4.
f
INTCLK
—12.8—MHz
Deviation from trimmed Internal oscillator
(2)(3)
12.8 MHz, fixed voltage, fixed temp
12.8 MHz, V
DD
± 10%, 0 to 70°C
12.8 MHz, V
DD
± 10%, –40 to 125°C
2. Deviation values assumes trimming @25•C and midpoint of voltage range.
3. Values are based on characterization results, not tested in production.
ACC
INT
—
—
—
± 0.4
± 2
—
—
—
± 5
%
Crystal frequency, XTALCLK
(1)
f
OSCXCLK
1—24MHz
External RC oscillator frequency, RCCLK
(1)
f
RCCLK
2—12MHz
External clock reference frequency
(1) (4)
4. No more than 10% duty cycle deviation from 50%.
f
OSCXCLK
dc — 32 MHz
Crystal load capacitance
(5)
5. Consult crystal vendor data sheet.
C
L
—20—pF
Crystal fixed capacitance
(3)
C
1
—
2 x C
L
——
Crystal tuning capacitance
(3)
C
2
—
2 x C
L
——
Feedback bias resistor
R
B
0.5 1 10 MΩ
RC oscillator external resistor
R
EXT
See Figure 16-4 —
Crystal series damping resistor
f
OSCXCLK
= 1 MHz
f
OSCXCLK
= 4 MHz
f
OSCXCLK
= > 8 MHz
R
S
—
—
—
20
10
0
—
—
—
kΩ
0
2
4
6
8
10
12
14
0 102030405060
R
EXT
(k
Ω
)
RC FREQUENCY, f
RCCLK
(MHz)
5 V 25°C