sy89840u Micrel Semiconductor, sy89840u Datasheet - Page 9

• Manufacturer Part Number: sy89840u
• Description: Precision Lvpecl Runt Pulse Eliminator 2 1 Multiplexer
• Manufacturer: Micrel Semiconductor

February 2005
Case #2 Input Clock Failure: Switching from a
selected clock stuck HIGH to a valid clock (RPE
enabled).
If CLK1 fails HIGH before the RPE MUX selects
CLK2 (using the SEL pin), the switchover will occur
in three stages.
Case #3 Input Clock Failure: Switching from a
selected clock stuck Low to a valid clock (RPE
enabled).
If CLK1 fails LOW before the RPE MUX selects
CLK2 (using the SEL pin), the switchover will occur
in two stages.
Micrel, Inc.
Note:
Output shows extended clock cycle during switchover. Pulse width for both high and low of this cycle will always be greater than 50% of
the CLK2 period.
Timing Diagram 2
Timing Diagram 3
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Stage 1: The output will remain HIGH for a limited
number of pulses of CLK2.
Stage 2: The output will switch to LOW and then
remain LOW for a limited number of falling edges of
CLK2.
Stage 3: The output will follow CLK2
Stage 1: The output will remain LOW for a limited
number of falling edges of CLK2.
Stage 2: The output will follow CLK2.
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SY89840U