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DC Trigger In Emitter Coupled Logic

IP.com Disclosure Number: IPCOM000078105D
Original Publication Date: 1972-Nov-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Blum, A: AUTHOR [+5]

Abstract

Many applications require level-sensitive triggers, using internal auxiliary flip-flops (FF) for the temporary storage of intermediate states. Such flip-flops can receive one set of information via their inputs, while emitting another via their outputs. The most widely used type is probably the master-slave FF which contains two internal FFs. But the circuit presented here has only one internal FF. is simpler, and uses fewer gates, at least when it is implemented in particular logic technologies, such as emitter-coupled logic (ECL).

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DC Trigger In Emitter Coupled Logic

Many applications require level-sensitive triggers, using internal auxiliary flip- flops (FF) for the temporary storage of intermediate states. Such flip-flops can receive one set of information via their inputs, while emitting another via their outputs. The most widely used type is probably the master-slave FF which contains two internal FFs. But the circuit presented here has only one internal FF. is simpler, and uses fewer gates, at least when it is implemented in particular logic technologies, such as emitter-coupled logic (ECL).

The circuit functionally belongs to the class known as J-K FFs and is subdivided into three parts (see the figure):
1) Input control blocks B1, B2.
2) Internal flip-flop (blocks B3...B6).
3) Output control blocks B7...B10. Similar to the master-slave FF there are two operational phases
1. A preparatory phase in which the clock pulse is active and

inputs J, K control the setting of the internal FF. Unlike the

masterslave FF, the original logical state of the

output is not stored in a second (slave) FF but kept constant

by a specific connection of the input and output control blocks.
2. A transfer phase in which the clock pulse is switched off and

the state of the internal FF is switched through to the outputs.

In detail there are four cases:

Case 1 - No change of output (J = K = O, or Q = 1, K = O., or J = Q = O) Both input control blocks B1 ("SET") and B2 ("RESET") remain inactive. The internal FF and the outputs "+ Q retain their original state, bo...