MT9040AN Zarlink Semiconductor, MT9040AN Datasheet - Page 13

• Manufacturer Part Number: MT9040AN
• Description: Description = Single Reference Frequency Selectable, 3.3V Digital PLL With Multiple Clock Outputs For Stratum 4 Applications ;; Package Type = Ssop ;; No. Of Pins = 48
• Manufacturer: Zarlink Semiconductor

MT9040
Data Sheet
MT9040
R=3.3M
74HC14
74HC14
LOCK
Lock
IN4148
+
C=1µf
Figure 8 - Time-constant Circuit
A digital alternative to the RC-time-constant circuit is presented in Figure 9. The circuit in Figure 9 can be used to
generate a steady lock signal. The circuit monitors the MT9040’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.
MT9040
Figure 9 - Digital Lock Pin Circuit
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Zarlink Semiconductor Inc.