| collector-base breakdown voltage |
| The minimum dc reverse bias voltage at which the collector-base junction of a transistor will allow a speci ied (non-destructive) current to flow. For an NPN transistor, it is measured with the collector positive, the base negative and the emitter open. |
| collector-emitter saturation volt age |
| A transistor biased normally and operating in the common-emitter mode is said to be in saturation when there is too little collector voltage remaining (or applied) for an increase in base drive to cause a significant increase in collector current. |
| collector-emitter breakdown voltage |
| The minimum dc voltage at which a transistor or darlington, biased in the normal direction with no optical or electrical input to the base, will allow a specified (non-destructive) current to flow. |
| current transfer ratio |
| For an optically coupled isolator, optical switch, reflective assembly or matched, emitter/detector pair: the ratio of the output current to the input current under specified conditions. |
| dark current |
| The current that flows through a photodetector when there is no optical input. (usually used in reference to photodiodes) |
| off state-collector current |
| The output of a transistor or darlington at no optical or electrical input to the base. |
| delay time |
| The time between the instant when an input step of light is applied to turn the photodetector on, and the instant when the resulting current flowing through the photodetector has increased to 10% of its final value. |
| emitter-collector breakdown voltage |
| The minimum dc voltage at which a transistor or darlington, biased opposite to its normal direction with no optical or electrical input to the base, will allow a specified (non-destructive) current to flow. |
| fall time |
| The time between the instant when the output of the photodetector is at 90% of its highest value and the instant when it has decreased to l0%c of its final value. |
| forward voltage |
| The voltage across a pn junction(diode) when it is forward biased at a specified current. |
| forward current |
| The current that flows across a semi-conductor junction when a forward bias voltage is applied. |
| half power angle |
| For radiation sources, the angle between half power points. |
| irradiance |
| The radiant (light) flux density incident on a surface; the amount of radiant flux upon a surface divided by the area of that surface, expressed in watts/square meter. |
| junction capacitance |
| Capacitance associated with a P-N junction; voltage dependent, decreasing with increase in reverse bias. |
| light current (general) |
| Current which flows through a photosensitive device when exposed to light. |
| off time |
| storage time + fall time |
| on time |
| delay time + rise time |
| on-state-collector current |
| The output current of a transistor at a specific optical or electrical input to the base. |
| peak wavelength |
| The wavelength at which the power output of an emitter is maximum. |
| propagation delay time |
| For a logic circuit, the time delay between a specified change in input and a corresponding change in the output logic state. Propagation delay time(low to high) is measured with the ouput changing from low to high and propagation delay time(high to low) with the output changing from high to low. |
| radiant intensity |
| The radiant (light) flux generated per unit solid angle in a given direction, expressed in milliwatts/steradian. |
| reverse break down voltage |
| The minimum reverse bias voltage at which a diode will conduct a specified (non-destructive) current: with no optical input. |
| reverse current |
| The current through a semiconductor diode when the n-region (cathode) is at a positive potential with respect to the p-region (anode). |
| rise time |
| The time between the instant when the output of the photodetector is at 10% of its final value and the instant when it has increased to 90% of its final value. |
| short-circuit current |
| The output current that flows through a photodiode when both terminals are tied together, at for a specified incident light. |
| spectral bandwith |
| The wavelength interval in which a spectral quantity is not less than half of its maximum value. |
| storage time |
| The time between the instant when the input step of light is removed (turning the photodetector off), and the instant when the current flowing through the photodetector has decreased to 90% of its "on" value. |
| total output power |
| The total light output power radiated by a device, expressed in watts or milliwatts. |
