Design of telephone line interface circuits using a two chip opto-coupler with LEDs integrated onto silicon chips

摘要

Design techniques are describes in which a telephone interface circuit or DAA can be realized using two silicon integrated circuits which include integrated opto couplers. The LED is formed on the chips using technologies which can be easily integrated onto a silicon integrated circuit such as porous silicon, avalanching PN junction, forward biased PN junction, deposited silicon carbide PN junction, deposited organic LED material such as conjugated polymers, or deposited GaAs LEDs. The light detector is realized using either a PN junction based detector or a Schottky diode detector depending on the wavelength of the light transmitted by the LED. The two integrated circuits can be placed in a single package with suitable optical links within the package. This technology thus eliminates the need for discrete opto couplers and transformers.