Datasheet
Oscillator
MC68HC912Dx128P Pierce Oscillator Specification
MC68HC912DT128A — Rev 4.0 Technical Data
MOTOROLA Oscillator 213
Figure 13-4. MC68HC912Dx128P Pierce Oscillator Architecture
There are the following primary differences between the previous
Colpitts (‘A’) and new Pierce (‘P’) oscillator configurations:
• Oscillator architecture was changed from Colpitts to Pierce.
• Hysteresis was added to the clock input buffer to reduce sensitivity
to noise.
• The bias current to the amplifier was optimized for less process
variation.
ALC
+
-
OTA
+
-
RFEEDBACK
EN
BIAS
Resonator
C
EX-VSS
C
X-VSS
BUF
RFLT
CFLT
2
GM
EXTAL XTAL
RESD
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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