US3287574A

US3287574A - Regenerative and-gate circuit producing output during shaping-pulse input upon coincidence with but regardless of continuous presence of other input

Info

Publication number: US3287574A
Application number: US351262A
Authority: US
Inventors: Glenn E Jenkins
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-03-11
Filing date: 1964-03-11
Publication date: 1966-11-22
Anticipated expiration: 1983-11-22

Description

Nov. 22, 1966 G. E. JENKINS 3,

REGENERATIVE AND-GATE CIRCUIT PRODUCING OUTPUT DURING SHAPING-PULSE INPUT UPoN COINCIDENCE WITH BUT REGARDLESS OF CONTINUOUS PRESENCE OF OTHER INPUT Filed March 11, 1964 OUTPUT k AND GATE Glenn E.Jenkins,

? INVENTOR.

Maw

United States Patent REGENERATIVE AND-GATE CIRCUIT PRODUC- ING OUTPUT DURING SHAPING-PULSE INPUT UPON COINCIDENCE WITH BUT REGARDLESS OF CONTINUOUS PRESENCE OF OTHER INPUT Glenn E. Jenkins, St. Paul, Minn., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Army Filed Mar. 11, 1964, Ser. No. 351,262 Claims. (Cl. 307-885) The invention relates generally to a regenerative shaper and more particularly to a means to shape and strobe the information output of a memory sense amplifier.

The need to produce a full width output pulse which is equal to the width of the strobe is presented when one is to shape and strobe the information output of a memory sense amplifier. Further, this full widthoutput pulse must be assured when a coincidence between the sense amplifier output pulse and the strobe pulse is established only at the leading edge of the strobe pulse. This must be done without the use of any feedback transformers.

It is, therefore, an object of this invention to provide a regenerative shaper suitable to shape and strobe the information output of a memory sense amplifier.

A further object is to provide a full width output pulse which is equal to the width of a strobe.

A still further object of the invention is to provide the above objects without the use of feedback transformers.

These and other objects and advantages of the present invention will become apparent from the following detailed description and from the accompanying drawings, in which the single figure is a schematic circuit diagram according to the invention.

In the drawing a transformer 2 has its primary winding 4 connected to receive signals from a memory sense amplifier, not shown. Secondary winding 6 is center tapped at tap 8. Two transistors 11 and 21 have their'base

electrodes

13 and 23 connected to opposite ends of the secondary winding 6 of transformer 2 by way of resistors 32 'and 34.

Emitter electrodes

16 and 26 of transistors 11 and 21 are connected to a common ground. Collector electrodes and 25 of transistors 11 and 21 are tied together by way of lead 36.

Transistor 41 has collector, emitter and

base electrodes

45, 46 and 43. Emitter electrode 46 is tied to tap 8 of the transformer by lead 48. The collector electrode 45 is connected to a negative source of power at terminal 51 by way of resistor 53. A source of bias power at terminal 54 is connected to emitter electrode 46 by way of a resistor 56. The base electrode 43 of transistor 41 is connected to junction 61.

A voltage divider network is formed between

terminals

63 and 64. The voltage divider is madeup of the series connections of

resistors

66, 67, and 68. A junction 69 is formed between

resistors

67 and 68. A rectifier 71 is connected between junction 69 and the lead 36 which ties the

collector electrodes

15 and 25 together.

An AND gate 72 is 'provided with two

input terminals

73 and 74 and an output terminal 75. Transistors 84 and 85 have their collector-emitter circuit connected in parallel with each other and in series with resistor 87, terminal 88 and a source of voltage (E). The output of the AND gate is connected across output terminal 75 and ground.

The emitter collector circuits of transistors 11 and 21 are supplied by a source of negative voltage at terminal 90 by way of resistor 92. The source of voltage at terminal 90 is further connected to the input terminal 74 of the AND gate by way of filter network 97. A source of bias voltage at terminal 93- is connected to input terminal 74 of the AND gate 72 by way of resistor 95.

A source of strobe pulses is connected to the input terminal 73 of the AND gate by way of filter circuit 100. Bias voltages connected at

terminals

101 and 102 are in circuit with input terminal 73 by way of

resistors

104 and 106.

The output terminal of the AND gate is connected to junction 69 by a rectifier 110. All the sources of voltages have their other terminal connected to a common ground.

Inthe absence of an input signal from the sense amplifier and assuming the strobe pulse is not being applied to the input 73 of the AND gate and, therefore, to the base of transistor the condition of the circuit is as follows: transistors 84 and 85 of the AND gate will be on resulting in an output voltage level of approximately zero volts output of the AND gate as all of the voltage of the source at terminal 88 will be absorbed by resistor 87. Junction 69, being fixed to the output of the AND gate by diode 110, will be held at approximately the same level. The emitter follower, transistor 41, applies a reverse bias level (determined primarily by the value of the threshold voltage at terminal 63) to transistors 11 and 21.

If an input signal of sufficient amplitude to turn on transistor 11 or 21 (the determining factor being the polarity of the memory sense-amplifier signal) is applied to transformer 2, then one input will be applied to the terminal 74 of the AND gate 72. This will turn off transistor 84.

Initiation of the strobe signal serves to provide the second input to the AND gate; therefore turning off transistor 85 and enabling the gate. The output terminal 75 of the gate will now fall negative. Junction 69 will follow the output until such time as it is clamped by rectifier 71 at a level (approximately -1 volt) which will sustain transistors 11 and 21 (whichever one was on) through the emitter follower circuit.

In the event the amplifier output signal is of a short duration after coincidence is established with the strobe pulse, the AND output is sustained in the following manner. When the rectifier transistor (11 or 21) starts to turn off, junction 69 will fall negative, and its final negative limit will be determined by the voltage divider network formed by

resistors

66, 67 and 68 or the output level (whichever is less negative). However, the negative voltage change of the junction 69 will be present at the base of transistors 11 and 21 by virtue of the emitter follower 41. Thus, transistor 11 or 21, or both, will be driven on and sustain the input to the AND gate; therefore sustaining the AND gate as long as the strobe pulse is present. The transistor 11 or 21 is held out of saturation during this time and thus provides a fast circuit recovery.

At the termination of the strobe signal, the input to terminal 73 of the gate will no longer be present; therefore, turning on transistor 85 and causing the output of the AND gate to fall to approximately zero volts. Junction 69 will follow the output voltage of the gate; therefore causing the threshold voltage applied to transistor 41 to become more positive resulting in reverse bias to transistors 11 and 21 will now be allowed to turn off; therefore resetting the system for another cycle of operation.

While the invention has been described with reference to a preferred embodiment thereof, it will be apparent that various modifications and other embodiments thereof will occur to those skilled in the art within the scope of the invention. Accordingly, I desire the scope of my invention to be limited only by the appended claims.

I claim:

1. A regenerative shaper for gate circuits comprising in combination: an AND gate having first and second input circuits, and an output circuit; means for providing a strobe signal which is connected to said first input circuit of the AND gate; signal means connected to an input circuit of a control means; said control means having an output circuit connected to the second input circuit o fthe AND gate; and means connecting said output 2. A regenerative shaper as set forth in claim 1, wherein said control means comprises two amplifiers each having an input circuit and an output circuit. v

3. A regenerative shaper as set forth in claim 2, wherein the output circuits of the amplifiers are connected in parallel with each other and in series with said second input circuit of the AND gate.

4. A regenerative shaper as set forth in claim 3 further comprising a transformer having a primary Winding-connected to said signal means and having a secondary winding connected in a series circuit with the input circuits of said amplifiers.

5. A regenerative shaper as set forth in claim 4, wherein said amplifiers are first and second transistors each having emitter, collector and base electrodes.

6. A regenerative shaper as set forth in claim 5 further including a thirdtransistor having emitter, collector and base electrodes; said secondary winding of said -trans former having a center tap connected to the emitter electrode of said third transistor, having one end connected to the base electrode of said first transistor and having another end connected to the base electrode of said second transistor; the collector electrode of the third transistor being connected to one terminal of a source of DC. voltage; said source of voltage having a second terminal connected to the emitter electrodes of both the first and second transistors; and a connection between the base electrode of the third transistor and said means connecting the output circuit of the AND gate to the g control means.

7. A regenerative shaper for gate circuits comprising first and second amplifier means each having an input circuit and an output circuit; an AND gate 'having first and second inputs and an output; a source of strobe pulses; a source of signal voltages; connections between the signalvoltages and said input circuit of said first amplifier means; means connecting the output circuit of said first'amplifier means to said first input of said AND gate; connection means connecting the output circuit of said second amplifier to the input circuit of the first amplifier; further means connected between. the input of the second amplifier and the output of said AND gate; and connections between said source of strobe pulses and the second input of said AND gate, so that said AND gate will have an output upon coincidence of signals on both of its inputs and will have the output for the entire time of the strobe pulse regardless of the time ofa signal from said source of signal voltages.

8. A regenerative shaper as set forth in claim 7 further comprising a source of bias voltage connected to the input circuit of said second amplifier; said bias voltage being of such magnitude that when there is an output from the AND gate there will be an output from the output circuit of said first amplifier.

9. A regenerative shaper as set forth in claim 8, wherein said further means connected between the input of the second amplifier and the output of said AND gate is a rectifier.

10. A regenerative shaper comprising in combination a source of signal voltages; a transformer having a primary winding and a center tapped secondary winding; said source of signal voltages being connected across said primary winding; first, second and third transistors each having an emitter, collector and base electrodes; the base electrodes of said first and second transistors being connected to opposite ends of said secondary winding of the transformer; the emitter electrode of said third transistor being connected to a center tap on the secondary winding; a source of voltage connected to supply the collector-emitter electrodes of said third transistor; means connecting the emitter electrodes of said first and second transistors of each other by way of a common ground connection; a first rectifier; both the collector electrodes of said first and second transistors being connected to one side of said rectifier; a source of voltage connected to supply the collector-emitter electrodes of said-first and second transistors; first, second and third resistors connected to each other in a series circuit and forming a first junction between said first and second resistors and a second junction between said second and third resistors; a source of voltage connected across saidseries circuit; said first-junction being connected to the base electrode of said third transistor; said second junction being connected to other side of saidrectifier; a source of strobe pulses; an AND gate having first and second input terminals and an output .terminal; connections between the source of strobe pulses References Cited by the Examiner UNITED STATES PATENTS 3,060,325 10/1962 Vinal 307 ss.5 3,192,404 6/1965 Jenkins 307 ss.s

ARTHUR GAUSS, Primary Examiner. J. HEYMAN, Assistant Examiner.

Claims

1. A REGENERATIVE SHAPER FOR GATE CIRCUITS COMPRISING IN COMBINATION: AN AND GATE HAVING FIRST AND SECOND INPUT CIRCUIT, AND AN OUTPUT CIRCUIT; MEANS FOR PROVIDING A STROBE SIGNAL WHICH IS CONNECTED TO SAID FIRST INPUT CIRCUIT OF THE AND GATE; SIGNAL MEANS CONNECTED TO AN INPUT CIRCUIT OF A CONTROL MEANS; SAID CONTROL MEANS HAVING AN OUTPUT CIRCUIT CONNECTED TO THE SECOND INPUT CIRCUIT OF THE AND GATE; AND MEANS CONNECTING SAID OUTPUT CIRCUIT OF THE AND GATE TO THE INPUT CIRCUIT OF SAID CONTROL MEANS, SO THAT SAID AND GATE WILL HAVE AN OUTPUT UPON COINCIDENCE OF SIGNALS ON BOTH OF ITS INPUT CIRCUITS AND WILL HAVE THE OUTPUT FOR THE ENTIRE TIME OF THE STROBE SIGNAL REGARDLESS OF THE TIME OF A SIGNAL FROM SAID SIGNAL MEANS.