DE3135464A1 - Comparator with hysteresis - Google Patents

Comparator with hysteresis

Info

Publication number
DE3135464A1
DE3135464A1 DE19813135464 DE3135464A DE3135464A1 DE 3135464 A1 DE3135464 A1 DE 3135464A1 DE 19813135464 DE19813135464 DE 19813135464 DE 3135464 A DE3135464 A DE 3135464A DE 3135464 A1 DE3135464 A1 DE 3135464A1
Authority
DE
Germany
Prior art keywords
comparator
hysteresis
reference voltage
output
voltage divider
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
DE19813135464
Other languages
German (de)
Inventor
Kurt 7153 Weissach i.T. Erbele
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bosch Telecom GmbH
Original Assignee
AEG Telefunken Nachrichtentechnik GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AEG Telefunken Nachrichtentechnik GmbH filed Critical AEG Telefunken Nachrichtentechnik GmbH
Priority to DE19813135464 priority Critical patent/DE3135464A1/en
Publication of DE3135464A1 publication Critical patent/DE3135464A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16576—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing DC or AC voltage with one threshold
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/30—Modifications for providing a predetermined threshold before switching
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/26—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback
    • H03K3/28—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback
    • H03K3/281—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator
    • H03K3/286—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator bistable
    • H03K3/2893—Bistables with hysteresis, e.g. Schmitt trigger
    • H03K3/2897—Bistables with hysteresis, e.g. Schmitt trigger with an input circuit of differential configuration
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K5/00—Manipulating of pulses not covered by one of the other main groups of this subclass
    • H03K5/01—Shaping pulses
    • H03K5/08—Shaping pulses by limiting; by thresholding; by slicing, i.e. combined limiting and thresholding
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
    • H03K2217/0036—Means reducing energy consumption

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Manipulation Of Pulses (AREA)

Abstract

The invention relates to a comparator with hysteresis which can be adjusted with arbitrary accuracy within wide limits, consisting of a differential amplifier stage and an output stage transistor. The object of specifying such a comparator with low power consumption, which can be monolithically integrated, is achieved by the fact that the reference voltage is changed by the position of the output voltage in such a manner that an additional current is impressed in the reference voltage divider with the aid of a current source. <IMAGE>

Description

Die Erfindung betrifft einen Komparator mit Hysterese, bestehend aus einer Differenzverstärkerstufe und einem Endstufentransistor.The invention relates to a comparator with hysteresis, consisting of a differential amplifier stage and an output stage transistor.

Solche Komparatoren werden z.B. in der analogen Signalverarbeitung in Auswerteschaltungen verwendet.Such comparators are used, for example, in analog signal processing in evaluation circuits.

Aus dem Buch von Tietze und Schenk: "Halbleiterschaltungstechnik" 3. Auflage, 1976, Kapitel 16.6.1, Seite 474 bis 476 ist eine Komparatorschaltung mit Hysterese bekannt, die z.B. zur Veränderung der Referenzspannung einen Spannungsteiler verwendet. Wenn eine solche Schaltung monolithisch integriert wird, ergibt sich wegen der hohen Fertigungstoleranz der Widerstände eine breite Toleranz der Hysterese. Außerdem hat eine solche Schaltung einen hohen Leistungsverbrauch.A comparator circuit with hysteresis is known from the book by Tietze and Schenk: "Semiconductor circuit technology" 3rd edition, 1976, chapter 16.6.1, pages 474 to 476, which uses a voltage divider, for example, to change the reference voltage. If such a circuit is monolithically integrated, there is a wide tolerance of the hysteresis because of the high manufacturing tolerance of the resistors. In addition, such a circuit has a high power consumption.

Der Erfindung liegt daher die Aufgabe zugrunde, einen Komparator mit in weiten Grenzen beliebig exakt einstellbarerThe invention is therefore based on the object of providing a comparator which can be set exactly as required within wide limits

Hysterese anzugeben, der einen sehr geringen Leistungsverbrauch aufweist und der auf einfache Weise monolithisch integrierbar ist.Specify hysteresis, which has a very low power consumption and which can be monolithically integrated in a simple manner.

Die Aufgabe wird gelöst wie im Anspruch beschrieben.The object is achieved as described in the claim.

Im folgenden sei die Erfindung anhand eines Ausführungsbeispiels mit Hilfe von Figuren näher beschrieben.In the following, the invention will be described in more detail using an exemplary embodiment with the aid of figures.

Figur 1 zeigt einen erfindungsgemäßen Komparator mit Hysterese.FIG. 1 shows a comparator according to the invention with hysteresis.

Figur 2 zeigt die Abhängigkeit der Ausgangsspannung Ua von der Eingangsspannung Ue eines Komparators nach Fig. 1.FIG. 2 shows the dependence of the output voltage Ua on the input voltage Ue of a comparator according to FIG. 1.

Im Ruhezustand sei die Eingangsspannung Ue negativ, bezogen auf die Referenzspannung, die durch den Spannungsteiler R1, R2 so eingestellt wird, daß der Transistor T6 leitend ist. Die Stromspiegelschaltung bewirkt, daß dann auch die Transistoren T6, T7 und T8 leitend sind, d.h., die Ausgangsspannung ist Ua ~ O Volt und die Referenzspannung wird, entsprechend dem Kollektorstrom von
<NichtLesbar>
angehoben.In the idle state, the input voltage Ue is negative, based on the reference voltage, which is set by the voltage divider R1, R2 in such a way that the transistor T6 is conductive. The current mirror circuit causes the transistors T6, T7 and T8 to be conductive, ie the output voltage is Ua ~ 0 volts and the reference voltage is corresponding to the collector current of
<notreadable>
raised.

Wenn die Eingangsspannung Ue in positiver Richtung steigt, dann wird ab einer bestimmten Schwelle der Transistor T2 leitend und somit die Transistoren T5, T6, T7 und T8 gesperrt.If the input voltage Ue rises in a positive direction, then from a certain threshold the transistor T2 becomes conductive and thus the transistors T5, T6, T7 and T8 are blocked.

Damit wird die Ausgangsspannung
<NichtLesbar>
und die Referenzspannung wird aufgrund des Spannungsteilers negativer, so daß der Transistor T6 noch weiter zumacht.This becomes the output voltage
<notreadable>
and the reference voltage becomes more negative due to the voltage divider, so that the transistor T6 closes even further.

Ändert sich die Eingangsspannung Ue wieder in negativer Richtung, dann muß sie einen negativeren Wert annehmen wegen der veränderten Referenzspannung bis der Transistor T6 wieder so weit leitend wird, daß die Transistoren T5, T7 und T8 wieder leitend werden und die Ausgangsspannung auf ~ 0 Volt angehoben wird.If the input voltage Ue changes again in a negative direction, then it must assume a more negative value because of the changed reference voltage until the transistor T6 is again conductive so that the transistors T5, T7 and T8 become conductive again and the output voltage is increased to ~ 0 volts will.

Die Differenz des Eingangssignals, mit der die Umschaltung des Transistors T8 erreicht wird, ergibt die Hysteresenbreite und hängt von der Parallelschaltung des Referenzspannungsteilers R1, R2 und dem Kollektorstrom T7 ab. Die Lage der Hysterese wird durch das Widerstandsverhältnis R1/R2 gebildet. Die Beträge der beiden Widerstände R1 und R2 sind so gewählt, daß sie ohne Probleme monolithisch integriert werden können.The difference in the input signal with which the switching of the transistor T8 is achieved gives the hysteresis width and depends on the parallel connection of the reference voltage divider R1, R2 and the collector current T7. The position of the hysteresis is formed by the resistance ratio R1 / R2. The magnitudes of the two resistors R1 and R2 are chosen so that they can be monolithically integrated without problems.

Claims (1)

Komparator mit Hysterese, bestehend aus einer Differenzverstärkerstufe und einem Rückkopplungsnetzwerk, dadurch gekennzeichnet, daß die Referenzspannung von der Lage der Ausgangsspannung (Ua) in der Weise verändert wird, daß parallel zu einem Widerstand (R2) des Referenzspannungsteilers (R1, R2) ein vom Ausgang der Differenzstufe über eine Stromspiegelschaltung gesteuerter Transistor geschaltet ist, der einen eingeprägten Zusatzstrom in den Spannungsteiler liefert, so daß eine je nach Verhältnis der Referenzspannungsteiler-Widerstände (R1, R2) einstellbare Hysterese entsteht und daß ein ebenfalls von der Stromspiegelschaltung gesteuerter Endstufentransistor den Ausgang des Komparators bildet.Comparator with hysteresis, consisting of a differential amplifier stage and a feedback network, characterized in that the reference voltage is changed by the position of the output voltage (Ua) in such a way that in parallel with a resistor (R2) of the reference voltage divider (R1, R2) one from the output the differential stage is connected via a current mirror circuit controlled transistor, which supplies an impressed additional current in the voltage divider, so that a hysteresis that can be set depending on the ratio of the reference voltage divider resistors (R1, R2) is created and that an output stage transistor also controlled by the current mirror circuit is the output of the comparator forms.
DE19813135464 1981-09-08 1981-09-08 Comparator with hysteresis Withdrawn DE3135464A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19813135464 DE3135464A1 (en) 1981-09-08 1981-09-08 Comparator with hysteresis

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19813135464 DE3135464A1 (en) 1981-09-08 1981-09-08 Comparator with hysteresis

Publications (1)

Publication Number Publication Date
DE3135464A1 true DE3135464A1 (en) 1983-05-26

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
DE19813135464 Withdrawn DE3135464A1 (en) 1981-09-08 1981-09-08 Comparator with hysteresis

Country Status (1)

Country Link
DE (1) DE3135464A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4016316A1 (en) * 1990-05-21 1991-11-28 Bosch Gmbh Robert EVALUATION FOR THE SIGNALS OF A SIGNAL SOURCE

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1286317A (en) * 1968-11-20 1972-08-23 Philips Electronic Associated Voltage-dependent trigger circuits
DE2360364A1 (en) * 1973-12-04 1975-06-12 Siemens Ag CIRCUIT ARRANGEMENT FOR COMPARING VOLTAGES
DE2538362B2 (en) * 1974-08-30 1979-10-04 Rca Corp., New York, N.Y. (V.St.A.) Input circuit for a comparator that works with hysteresis
EP0009354A1 (en) * 1978-09-08 1980-04-02 Fujitsu Limited Waveform shaping circuit
DE3013172A1 (en) * 1979-04-05 1980-10-23 Toko Inc TRANSISTOR CIRCUIT WITH TWO COMPARISON LEVELS
US4259601A (en) * 1978-12-08 1981-03-31 Motorola, Inc. Comparison circuit having bidirectional hysteresis

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1286317A (en) * 1968-11-20 1972-08-23 Philips Electronic Associated Voltage-dependent trigger circuits
DE2360364A1 (en) * 1973-12-04 1975-06-12 Siemens Ag CIRCUIT ARRANGEMENT FOR COMPARING VOLTAGES
DE2538362B2 (en) * 1974-08-30 1979-10-04 Rca Corp., New York, N.Y. (V.St.A.) Input circuit for a comparator that works with hysteresis
EP0009354A1 (en) * 1978-09-08 1980-04-02 Fujitsu Limited Waveform shaping circuit
US4259601A (en) * 1978-12-08 1981-03-31 Motorola, Inc. Comparison circuit having bidirectional hysteresis
DE3013172A1 (en) * 1979-04-05 1980-10-23 Toko Inc TRANSISTOR CIRCUIT WITH TWO COMPARISON LEVELS

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DE-Z: radio fernsehen elektronik, Nr.22, 1973, H.4, S. 448 *
US-Z: IBM Technical Disclosure Bulletin, Vol.14, Nr. 10, März 1971, S.3122 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4016316A1 (en) * 1990-05-21 1991-11-28 Bosch Gmbh Robert EVALUATION FOR THE SIGNALS OF A SIGNAL SOURCE
DE4016316B4 (en) * 1990-05-21 2004-02-12 Robert Bosch Gmbh Evaluation circuit for the signals of a signal source

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8139 Disposal/non-payment of the annual fee