MT9045AN Zarlink Semiconductor, Inc., MT9045AN Datasheet - Page 19

• Manufacturer Part Number: MT9045AN
• Description: Framer, Framer Circuit, T1/E1/OC3 System Synchronizer
• Manufacturer: Zarlink Semiconductor, Inc.

MT9045
Data Sheet
MT9045
R=3.3M
74HC14
74HC14
Lock
LOCK
IN4148
+
C=1µf
Figure 11 - Time-constant Circuit
A digital alternative to the RC-time-constant circuit is presented in Figure 12. The circuit in Figure 12 can be
used to generate a steady lock signal. The circuit monitors the MT9045’s LOCK pin, as long as it detects a
positive pulse every 1.024 seconds or less, the Advanced Lock output will remain high. If no positive pulse is
detected on the LOCK output within 1.024 seconds, the Advanced LOCK output will go low.
Figure 12 - Digital Lock Pin Circuit
Zarlink Semiconductor Inc.
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