MC68HC908AZ32ACFU MOTOROLA [Motorola, Inc], MC68HC908AZ32ACFU Datasheet - Page 160

• Manufacturer Part Number: MC68HC908AZ32ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Clock Generator Module (CGM)
Advance Information
160
The K factor in the equations is derived from internal PLL parameters.
K
K
Acquisition and Tracking Modes
Note the inverse proportionality between the lock time and the reference
frequency.
In automatic bandwidth control mode, the acquisition and lock times are
quantized into units based on the reference frequency. (See
and Automatic PLL Bandwidth Modes
number of clock cycles, n
within the tracking mode entry tolerance,
mode. A certain number of clock cycles, n
that the PLL is within the lock mode entry tolerance,
acquisition time, t
acquisition to lock time, t
since the average frequency over the entire measurement period must
be within the specified tolerance, the total time usually is longer than
t
Lock
acq
trk
Freescale Semiconductor, Inc.
•
•
•
•
is the K factor when the PLL is configured in tracking mode. (See
For More Information On This Product,
is the K factor when the PLL is configured in acquisition mode, and
as calculated above.
Correct selection of filter capacitor, C
Capacitor
Room temperature operation
Negligible external leakage on CGMXFC
Negligible noise
Clock Generator Module (CGM)
Go to: www.freescale.com
on page 159).
ACQ
, is an integer multiple of n
t
al
t
acq
AL
=
ACQ
t
, is an integer multiple of n
Lock
=
------------------- -
f
, is required to ascertain that the PLL is
CGMRDV
V
=
------------------- -
f
DDA
CGMRDV
V
t
on page 141).
ACQ
DDA
+
----------- -
K
on page 141). A certain
TRK
TRK
t
TRK
4
F
AL
------------ -
K
(see
, before exiting acquisition
, is required to ascertain
ACQ
8
ACQ
68HC908AZ32A — Rev 0.0
Choosing a Filter
/f
TRK
Lock
CGMRDV
/f
. Therefore, the
CGMRDV
MOTOROLA
Manual
, and the
. Also,