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Three Transistor Ternary Latch

IP.com Disclosure Number: IPCOM000096063D
Original Publication Date: 1964-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Trampel, KM: AUTHOR

Abstract

Three transistors T1, T2, and T3 are interconnected to form a three-way latch. A network of resistors transforms the three states into three voltage levels at the output. Each transistor has a resistor R1, R2 or R3 connected directly to its collector terminal. Each collector is connected to the other two collector terminals by the series resistor-diode combination D1R4, D2R5, D3R6.

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Three Transistor Ternary Latch

Three transistors T1, T2, and T3 are interconnected to form a three-way latch. A network of resistors transforms the three states into three voltage levels at the output. Each transistor has a resistor R1, R2 or R3 connected directly to its collector terminal. Each collector is connected to the other two collector terminals by the series resistor-diode combination D1R4, D2R5, D3R6.

The diodes give a transistor a different circuit relationship with respect to each of the three collector resistors. For example, when transistor T1 is on, it conducts in series with resistor R1 directly. It conducts in series with R2 through the diode resistor combination D2R5.

Also, it conducts in circuit with R3 through the two series combinations D2R5 and D3R6. This operation establishes a low voltage level at the collector terminal of T1, an intermediate voltage level at the collector terminal of T2, and a higher voltage level at the collector terminal of T3. As the circuit is switched through its three states, these voltage levels appear in succession at the output terminal.

The base terminals of the transistors are coupled to the collector terminals by resistor pairs R7R8, R9R10, and R11R12 to latch the circuit. Such latching is in a state in which one transistor is turned on and the other two transistors turned off.

Each transistor has a capacitor C1, C2 or C3 and a resistor R13, R14 or R15. These are connected between an input terminal and the co...