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Three-Level Exclusive OR

IP.com Disclosure Number: IPCOM000098060D
Original Publication Date: 1961-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

McAnney, WH: AUTHOR

Abstract

This three-level circuit receives first and second input signals in any one of first, second or third signal levels, i.e., positive, negative or ground signal levels. The circuit has one output signal when first and second input levels are unlike and not at ground and a second output signal when the input levels are alike and not at ground.

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Three-Level Exclusive OR

This three-level circuit receives first and second input signals in any one of first, second or third signal levels, i.e., positive, negative or ground signal levels. The circuit has one output signal when first and second input levels are unlike and not at ground and a second output signal when the input levels are alike and not at ground.

The circuit has a pair of similar sections. One section consists of common emitter amplifiers T1...T4. The other consists of common emitter amplifiers T8...T11. These amplifiers connect to one of a plurality of common base amplifiers T5, T6 and T7. Current source 20 or 21 magnitude connects to the T5 emitter as well as biasing the T1 and T3 collectors. Current source 22 of 21 magnitude connects to the emitter of T6 as well as biasing the T2, T10 and T11 collectors. Current source 24 of 21 magnitude connects to the T7 emitter as well as biasing the T4, T8 and T9 collectors. Each emitter of the amplifier connects through a resistor to a current sink. The T1 and T4 emitters interconnect and share resistor 28 connected to sink 26. The T2 and T3 emitters inter connect and share resistor 32 connected to sink 30. Current sinks 34 and 40 connect through resistors 36 and 42 to the T9, T10 and T8, T11 emitters, respectively. The T5 and T7 collectors connect through bias resistors 44 and 46, respectively, to -V. The T6 collector connects through resistor 48 to ground. The T6 collector also connects to that of T7 and to output 50. Diode D2 interconnects the collector T5 with that of T6. Diode D1 clamps the collector of T5 to ground. Inputs A and B having first, second and third levels, i.e., positive, negative and ground levels, respectively, are supplied to the T10, T11 and T1, T2 bases, respectively. The T3 and T9 bases connect to -V. The T4 and T8 bases are grounded...