Electrical Characteristics
MC9S12XHY-Family Reference Manual, Rev. 1.01
748
Freescale Semiconductor
A.6.2
Oscillator
A.6.3
Phase Locked Loop
A.6.3.1
Jitter Information
With each transition of the clock f
cmp
, the deviation from the reference clock f
ref
is measured and input
voltage to the VCO is adjusted accordingly.The adjustment is done continuously with no abrupt changes
in the clock output frequency. Noise, voltage, temperature and other factors cause slight variations in the
Table A-21. Oscillator Characteristics
Conditions are shown in Table A-4. unless otherwise noted
Num C
Rating
Symbol
Min
Typ
Max
Unit
1a
C Crystal oscillator range (loop controlled Pierce)
f
OSC
4.0
—
16
MHz
2
P Startup Current
i
OSC
100
—
—
µ
A
3a
C Oscillator start-up time (LCP, 4MHz)
1
1
These values apply for carefully designed PCB layouts with capacitors that match the crystal/resonator requirements..
t
UPOSC
—
2.2
10
ms
3b
C Oscillator start-up time (LCP, 8MHz)
1
t
UPOSC
—
1.1
8
ms
3c
C Oscillator start-up time (LCP, 16MHz)
1
t
UPOSC
—
0.75
5
ms
5
D Clock Quality check time-out
t
CQOUT
0.45
—
2.5
s
6
P Clock Monitor Failure Assert Frequency
f
CMFA
200
400
800
KHz
7
P External square wave input frequency
f
EXT
2.0
—
50
MHz
8
D External square wave pulse width low
t
EXTL
9.5
—
—
ns
9
D External square wave pulse width high
t
EXTH
9.5
—
—
ns
10
D External square wave rise time
t
EXTR
—
—
1
ns
11
D External square wave fall time
t
EXTF
—
—
1
ns
12
D Input Capacitance (EXTAL, XTAL pins)
C
IN
—
7
—
pF
13
P EXTAL Pin Input High Voltage
V
IH,EXTAL
0.75*V
DDPLL
—
—
V
T EXTAL Pin Input High Voltage
,2
2
Only applies if EXTAL is externally driven
V
IH,EXTAL
—
—
V
DDPLL
+ 0.3
V
14
P EXTAL Pin Input Low Voltage
V
IL,EXTAL
—
—
0.25*V
DDPLL
V
T
EXTAL Pin Input Low Voltage
,2
V
IL,EXTAL
V
SSPLL
- 0.3
—
—
V
15
C EXTAL Pin Input Hysteresis
V
HYS,EXTAL
—
180
—
mV
16
C
EXTAL Pin oscillation amplitude (loop controlled
Pierce)
V
PP,EXTAL
—
0.9
—
V
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