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Renesas Electronics America - Knowledgebase

What are the propagation delay time of H → L) tPHL and (L → H) tPLH?

Latest Updated:02/01/2008


These refer to the delay time from the change of forward current until the change of output voltage, when a pulsating forward current (IF) flows into the light-emitting side.
These two times may seem to refer to "rise time tr" and "fall time tf", but the definition is different. They actually refer to the time "from the change of input until the change of output."

The transfer delay time and test circuit shown on the data sheet of the PS9115 are reproduced below.

Suitable Products
Diodes for Constant Voltage
Photocouplers / Optocouplers