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Transistor-tunnel Device Logic

IP.com Disclosure Number: IPCOM000096956D
Original Publication Date: 1962-Feb-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Gersbach, JE: AUTHOR

Abstract

Logic circuits, operable at high speed and capable of driving a plurality of either similar or complementary circuits, use transistors and tunnel devices. The circuits respond to small voltage swings and employ low impedance elements.

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Transistor-tunnel Device Logic

Logic circuits, operable at high speed and capable of driving a plurality of either similar or complementary circuits, use transistors and tunnel devices. The circuits respond to small voltage swings and employ low impedance elements.

An OR having two power supplies has transistors T1...Tn connected in parallel. The transistors have a common emitter circuit, including resistor R1 coupling a -V voltage. There is a common collector output circuit, including resistor R3 coupling a +V voltage supply. The emitter circuit also includes tunnel rectifier D1 referenced to ground. The collector circuit connects to an output circuit including tunnel devices D2 and D3. D3 is either a tunnel diode or tunnel rectifier and clamps the output voltage in both directions. D2 is a tunnel rectifier having load resistor R2. It provides inverted outputs A and B at either terminal for driving either similar or complementary circuits.

Each transistor base accepts an input signal, variable between -V and ground levels. When the input signals are at the -V level, the transistors are nonconducting. Conduction takes place from ground reference potential to -V through D1 and R1, D1 operating at point 1 on its V-I characteristic. The voltage at the transistor collectors and, thus, at B, is clamped by D3 at a +V level determined by the +V supply. Output A is at ground potential. When any one input signal rises to ground potential, the corresponding transistor conducts and D1 is switched to the low conductive state indicated at the point 2. Then, the major portion of the current flow is through the conducting transistor. The voltage level) at its collector falls, switching...