High-speed driver for an LED communication system or the like
AssigneeAT&T Bell Laboratories
InventorsLisa A. Peterson, Stefan A. Siegel
Life of this patent
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Abstract
A high-speed driver for LED data communications systems. A differentiator provides a turn-on and a turn-off pulse of current to the LED. The amount of charge delivered during turn-off is adjusted to sweep substantially all of the carriers from the LED without reverse-biasing the LED.
Claims11
A driver for an LED or the like having an active region for producing light from recombinant carriers therein, the driver having a means for providing a ON current of a first polarity and an OFF current to the LED in response to an input, pulse characterized by:
- a differentiator, responsive to the input pulse for providing a predetermined amount of charge in a turn-off pulse of current to the LED when the LED is to be turned off, the turn-off pulse of current having a polarity opposite the first polarity;
- wherein the amount charge is sufficient to sweep substantially all of the carriers from the LED active region.
A driver for an LED or the like having an active region for producing light from recombinant carriers therein, the driver having a means for providing a ON current of a first polarity and a substantially zero OFF current to the LED in response to an input pulse, characterized by:
- a first differentiator, responsive to the input pulse, for providing a predetermined amount of charge in a turn-off pulse of current to the LED when the LED is to be turned off, the turn-off pulse of current having a polarity opposite the first polarity;
- wherein the amount of charge is limited such that the LED remains forward biased.
Dependencies are inferred from the claim text.