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Direct Coupled Transistor Esaki Diode Logic

IP.com Disclosure Number: IPCOM000097634D
Original Publication Date: 1961-Mar-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Gruodis, AJ: AUTHOR [+2]

Abstract

The negative resistance characteristic of an Esaki diode is used in conjunction with transistors to provide uniquely advantageous logical circuitry.

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Direct Coupled Transistor Esaki Diode Logic

The negative resistance characteristic of an Esaki diode is used in conjunction with transistors to provide uniquely advantageous logical circuitry.

In the basic logic circuit, the Esaki diode is used as the collector load impedance for the transistors. The Esaki diode characteristic becomes a non- linear load line for the family of I(c) - V(c) curves of the transistors. When a single transistor is OFF, the operating point of the circuit is at 1. This enables the +V supply to provide current to the succeeding state substantially equal to the peak current value of the Esaki diode with a very small voltage drop. In the ON state of the transistor, the operating point is at 2. The transistor is in saturation near the valley current of the Esaki diode. To switch from point 1 to point 2, an input current is supplied to the transistor equal in magnitude to the peak current (I(p)) of the Esaki diode divided by the base to collector current gain (alpha') of the transistor. Operation returns to point 1 when the transistor is rendered nonconducting. At point 2, the output voltage is not sufficient to turn the next stage on. Thus, each stage is capable of driving others.

Logic is performed as shown by connecting a plurality of transistors to a single Esaki diode. The resultant logic block provides a low impedance output having low power dissipation and a large available output current. Also, this configuration permits direct couple...