Datasheet

Oscillator
MC68HC912D60P Pierce Oscillator Specification
MC68HC912D60A — Rev. 3.1 Technical Data
Freescale Semiconductor Oscillator 195
Figure 12-4. MC68HC912D60P 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