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Circuit to Increase Switching Speed of Infrared Light-Emitting Diodes

IP.com Disclosure Number: IPCOM000039901D
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01

Publishing Venue

IBM

Related People

Authors:
Bustamante, C Zalph, W [+details]

Abstract

This article describes a circuit arrangement which speeds up the switching times of infrared (IR) light-emitting diodes (LEDs) to maximize transmitted data throughputs and provide compatibility between previously incompatible parts. The diode speeds are not the only aspect which limit communication speed of the IR media. Due to other design considerations, such as, receiver bandwidths, optical multi-path distortion and resultant digital jitter, and bit-error-rate (BER) versus signal-to-noise ratio (S/N) as a function of throughput, this media will use 500-nanosecond pulses within a pulse position modulation (PPM) type of encoding. The disclosed circuit provides a means to speed up diode switching speeds, thereby making commercially available diodes switch in less than 500 nanoseconds.