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Browse Prior Art Database

Complementary Current Switch

IP.com Disclosure Number: IPCOM000051100D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Montegari, FA: AUTHOR

Abstract

The complementary current switch utilizes NPN and both isolated and non-isolated PNP transistors to provide both OR and AND functions and dual-phase emitter follower outputs.

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Complementary Current Switch

The complementary current switch utilizes NPN and both isolated and non- isolated PNP transistors to provide both OR and AND functions and dual-phase emitter follower outputs.

The functions available are OR, AND, NOR, and NAND. Dotting of circuits is not necessary since inputs may be extended to provide as many inputs in one circuit as desired.

Transistors T1 and T4 together with collector load resistor R3 and emitter current source resistor R4 form an NPN current switch.

Transistors T2 and T3 together with collector load resistor R2 and emitter current source resistor R1 form a PNP current switch.

The collector of input NPN transistor T1 is connected to the emitters of PNP transistors 12 and T3. The collector of input PNP transistor 12 is connected to the emitters of NPN transistors T1 and T4. Thus, a dual complementary current switch is formed.

Both the NPN and PHP current switches may be turned on and off by either the HPN or PNP input transistor.

The drawing shows only one input NPN and one input PHP; however, both inputs may be extended to the desired number. Multiple NPH inputs provide the AND, NAND functions, and multiple PNP inputs provide the OR, NOR functions.

Emitter followers T5, 16 provide low impedance outputs and level shifting to make the output levels symmetrical.

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