What is the notation and terminology for a Phototransistor output?

The following table provides a description of notation and terminology used in catalogs for Photomicrosensors built into equipment with a phototransistor output.

Phototransistor Output

Notation Item Description
IFP Pulse forward current The maximum pulse current that is allowed to flow continuously from the
anode to cathode of an LED under a specified temperature, a repetition
period, and a pulse width condition.
Ic Collector current The current that flows to the collector junction of a phototransistor.
Pc Collector dissipation The maximum power that is consumed by the collector junction of a
phototransistor.
ID Dark current The current leakage of the phototransistor when a specified bias voltage is
imposed on the phototransistor so that the polarity of the collector is positive
and that of the emitter is negative on condition that the illumination of the
Photomicrosensor is 0 lx.
IL Light current The collector current of a phototransistor under a specified input current
condition and at a specified bias voltage.
VCE(sat) Collector-emitter
saturated voltage
The ON-state voltage between the collector and emitter of a phototransistor
under a specified bias current condition.
ILEAK Leakage current The collector current of a phototransistor under a specified input current
condition and at a specified bias voltage when the phototransistor is not
exposed to light.
tr Rising time The time required for the leading edge of an output waveform of a
phototransistor to rise from 10% to 90% of its final value when a specified
input current and bias condition is given to the phototransistor.
tf Falling time The time required for the trailing edge of an output waveform of a
phototransistor to decrease from 90% to 10% of its final value when a
specified input current and bias condition is given to the phototransistor.
VCEO Collector-emitter voltage The maximum positive voltage that can be applied to the collector of a
phototransistor with the emitter at reference potential.
VECO Emitter-collector voltage The maximum positive voltage that can be applied to the emitter of a
phototransistor with the collector at reference potential.

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