EP0011704B1 - Voltage reference source, in particular for amplifier circuits - Google Patents

Voltage reference source, in particular for amplifier circuits Download PDF

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Publication number
EP0011704B1
EP0011704B1 EP79104039A EP79104039A EP0011704B1 EP 0011704 B1 EP0011704 B1 EP 0011704B1 EP 79104039 A EP79104039 A EP 79104039A EP 79104039 A EP79104039 A EP 79104039A EP 0011704 B1 EP0011704 B1 EP 0011704B1
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Prior art keywords
transistor
circuit
reference voltage
transistors
emitter
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EP79104039A
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German (de)
French (fr)
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EP0011704A1 (en
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Horst Dipl.-Ing. Krämer
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Siemens AG
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Siemens AG
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F3/00—Non-retroactive systems for regulating electric variables by using an uncontrolled element, or an uncontrolled combination of elements, such element or such combination having self-regulating properties
    • G05F3/02—Regulating voltage or current
    • G05F3/08—Regulating voltage or current wherein the variable is dc
    • G05F3/10—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics
    • G05F3/16—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices
    • G05F3/20—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices using diode- transistor combinations
    • G05F3/26—Current mirrors
    • G05F3/265—Current mirrors using bipolar transistors only

Definitions

  • reference voltage sources are already known. Most of the time, the voltage drop across diode sections is used as the standard, for which the base-mitter sections of transistors can also be used (see DE-C-17 62 924, DE-B-17 63 016). Instead of diodes, transistors are used whose base collector path is short-circuited (see "Control Technology", Issue 1, 1969, page 13; Siemens Data Book 1974/75, Volume 2, “Linear Circuits", pages 213 to 215). All of these reference voltage sources can e.g. can be used to stabilize the operating points of amplifier circuits. Amplifier circuits which are constructed with the aid of differential amplifiers are particularly suitable.
  • a reference voltage source is also known (US-A-4 085 359), in which the collector current of one transistor of the reference voltage source is mirrored on the collector current of the other transistor, and the emitter areas of the transistors and the resistance values are defined in this way that the reference voltage is largely independent of the temperature.
  • the invention is based on the object of improving the usability of such reference voltage sources.
  • the improvement relates in particular to measures which ensure that the reference voltage maintains its intended size regardless of the load.
  • a reference voltage source is assumed in which the reference voltage is present at the interconnected bases of two transistors, one of which is connected as a diode, while the other is operated normally.
  • such a reference voltage source is characterized in that the current mirror circuit includes a further transistor connected in a current mirror circuit, which is connected in series with a corresponding transistor connected to reference potential, the base of which is connected to the emitter of the transistor connected as a diode, and dab the The reference voltage at the connection point between the collector and emitter of the transistors connected in series for a circuit to be supplied is taken off.
  • Current mirror circuits as are known per se can be used here (see DE-A-24 40 023, 26 42 874; Philips Technische Rundschau 1971/72, No. 1, pages 4 to 8; crizstechnik, Haft 1, 1969, page 13 ).
  • the reference voltage is taken from a tap of the series connection of the two transistors in question, a load on the inner reference circuit point of the reference voltage source is avoided, even if the tap is used as a current source or current sink for stabilizing the operating point of the circuit supplied. This ensures a particularly high constancy of the reference voltage. It is also advantageous that the voltage requirement for the reference voltage source is very small. Their minimum operating voltage is only above the saturation voltage of transistor T6 above the reference voltage applied to the base of transistor T2.
  • the current mirror circuit includes an additional transistor which feeds a further current mirror circuit which has transistors which are looped into circuits of the circuit supplied with the reference voltage. Constant current effects for the supplied circuit are thereby brought about in a convenient manner.
  • the reference voltage source RG and the amplifier circuit VS are shown.
  • the input of the amplifier circuit VS is at the terminals E1 and E2.
  • the output is at sources A3 and A4.
  • This amplifier circuit is a microphone amplifier.
  • the acoustic-electrical converter, in particular a piezoelectric ceramic, is connected to the input terminals E1 and E2.
  • the operating voltage + / 0 is supplied via the output terminals A3 and A4, which is then superimposed on the output signal.
  • the reference voltage supplied by the reference voltage source RG is now also applied to the input terminal E1. With your help, the operating point of the differential amplifier with the transistors T13 and T14, which belongs to the amplifier circuit, is stabilized.
  • the reference voltage source itself initially includes the transistor T2 connected as a diode and the normally operated transistor T1. The bases of these two transistors are connected and give the inner reference voltage point.
  • the current mirror circuit with the transistors T4 and T5 and the resistors R1 and R2 is looped into the collector circuits of the transistors T1 and T2. It also includes the transistor T6 with the resistor R3, which is connected in series with the transistor T8, which is still connected to the reference potential 0.
  • the base of transistor T8 is connected to the emitter of transistor T2 and to the tap of the series circuit made up of emitter resistors R6 and R7, which serve as emitter resistors for transistors T1 and T2.
  • connection point between the collector of transistor T6 and the The emitter of the transistor T8 is connected to the input terminal E1. So here the reference voltage for the circuit VS supplied with it is taken off.
  • the level of the reference voltage is selectively determined by the voltage at the inner reference voltage point, namely the connected bases of the transistors T1 and T2. With the aid of the output circuit formed by the transistors T8 and T6, however, this inner reference voltage point is prevented from being loaded by the decrease in the reference voltage.
  • the transistors T6 and T8 belonging to the output circuit can act as a current source or current sink. A load on the inner reference voltage point is avoided during operation.
  • the reference voltage source RG is supplemented by the starting circuit comprising the series circuit of the transistor T3 and its emitter resistor R5.
  • the operating voltage + / 0 is applied to this starting circuit.
  • the base of the transistor T3 is connected to the collector of the transistor T1. This ensures that when the operating voltage is applied, the intended reference voltage is set at the inner reference circuit point.
  • the area of the emitter of the transistor T2 connected as a diode is a fraction of the area of the emitter of the other associated transistor T1.
  • This and the additional circuit measures provided result in temperature compensation insofar as the reference voltage obtained is largely independent of the temperature (see also Control Technology, Issue 1, 1969, page 13; DE-B-19 440 28, column 1).
  • the area of the emitter of transistor T1 is five times the area of the emitter of transistor T2. This is also indicated there by the inscribed numbers 5 and 1.
  • the number of ohms is also written for each of the various resistors belonging to the circuit.
  • the ratio of the resistance values of the emitter resistors R6 and R7 is also important for the temperature compensation.
  • On the basis of the symbols chosen for the representation of the transistors it can also be recognized whether it is a pnp transistor or an npn transistor.
  • an additional transistor belongs to the current mirror circuit, namely the transistor T7 with an emitter resistor R4, which feeds a further current mirror circuit.
  • This is the current mirror circuit with transistors T9, T10, T11, T12 and T19.
  • the last three listed transistors are looped into circuits of the amplifier circuit VS supplied with the reference voltage.
  • the transistor T11 1 is looped into the emitter circuit of the differential amplifier with the transistors T13 and T14, the emitter resistors R12 and R13 and the collector resistors R8 and R9.
  • the transistor T12 is looped into the main circuit of the transistor T20, which belongs to an intermediate amplifier of the amplifier circuit VS.
  • the transistor T19 is looped into a current branch of a current mirror circuit belonging to the amplifier circuit, to which i.a. the transistors T17, T18 and T22 and the resistors R20 and R22 belong.
  • This circuit technology achieves a specific current impression for the amplifier circuit, for which purpose switching means are used which can be conveniently attached to the switching means belonging to the reference voltage source.
  • the size of the associated emitter areas is indicated by the numbers written on them.
  • the number 1 is written on the transistors T7, T10 and T19, while the number 2 is written on the transistors T11 and T12. Accordingly, the two latter transistors carry a main current twice as large as the other three transistors mentioned in this context.
  • the size of the emitter areas is indicated by the numbers written on them. Accordingly, the transistor T6 has an emitter area three times as large as the transistors T1 and T5.
  • the strength of the currents flowing across the main current paths of the named transistors is graded according to the size of their emitter areas. Accordingly, the strength of the currents flowing in those circuits into which these transistors are looped is graded.
  • the amplifier circuit VS also includes the symmetrically switched transistor coupling stage with transistors T15 and T16, via which the differential amplifier has a two-stage intermediate amplifier is connected, to which the transistors T20 and T21 belong, to which a Darlington amplifier with the transistors T23 and T24 is then connected as an output stage.
  • the transistors T15 5 and T16 of the transistor coupling stage also belong to the current mirror circuit with the transistors T17 and T18.
  • the coupling stage and the input stage are set in a current-symmetrical manner.
  • the voltage feedback network with the resistors R19, R18, R15, R17, R16, R14, R11 and R10 is also inserted between the output and the input.
  • the gain factor of the amplifier circuit is determined (see also Siemens data book 1974/75, Bad 2, "Linear circuits", pages 213 to 215).
  • the negative feedback capacitor C1 then also contributes to the stabilization.
  • the transistors T23 and T24 of the output stage each have their own collector resistors, namely the collector resistors R21 and RL. This results in a particularly high modulation capability of the output stage and a low saturation voltage of the transistor T24.
  • arrows labeled “lK” or “21K” are drawn, which indicate the direction and the size of the currents flowing in the relevant current branches. These currents result primarily from the fact that the current mirror circuits described are provided.
  • the microphone amplifier described above is also designed in terms of circuit technology in such a way that it can be easily implemented within an integrated circuit. Its advantageous properties are retained.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Amplifiers (AREA)
  • Control Of Electrical Variables (AREA)

Description

Es sind bereits verschiedene Varianten von Referenzspannungsquellen bekannt. Meistens wird dabei als Normal der Spannungsabfall an Diodenstrecken ausgenutzt, wofür auch die Basismitterstrecken von Transistoren infrage kommen (siehe DE-C-17 62 924, DE-B-17 63 016). Anstelle von Dioden werden Transistoren benutzt, deren Basiskollektorstrecke kurzgeschlossen ist (siehe "Regelungstechnik", Heft 1, 1969, Seite 13; Siemens-Datenbuch 1974/75, Band 2, "Lineare Schaltungen", Seiten 213 bis 215). Alle diese Referenzspannungsquellen können z.B. zur Stabilisierung der Arbeitspunkte von Verstärkerschaltungen benutzt werden. Dabei kommen vor allem Verstärkerschaltungen infrage, welche mit Hilfe von Differenzverstärken aufgebaut sind. Wieterhin ist eine Referenzspannungsquelle gemäß dem Oberbegriff des Anspruchs 1 bekannt (US-A-4 085 359), bei der der Kollektorstrom des einen Transistors der Referenzspannungsquelle auf den Kollektorstrom des anderen Transistors gespiegelt wird und wobei die Emitterflächen der Transistoren und die Widerstandswerte so festgelegt sind, daß die Referenzspannung von der Temperatur weitgehend unabhängig ist.Different variants of reference voltage sources are already known. Most of the time, the voltage drop across diode sections is used as the standard, for which the base-mitter sections of transistors can also be used (see DE-C-17 62 924, DE-B-17 63 016). Instead of diodes, transistors are used whose base collector path is short-circuited (see "Control Technology", Issue 1, 1969, page 13; Siemens Data Book 1974/75, Volume 2, "Linear Circuits", pages 213 to 215). All of these reference voltage sources can e.g. can be used to stabilize the operating points of amplifier circuits. Amplifier circuits which are constructed with the aid of differential amplifiers are particularly suitable. A reference voltage source is also known (US-A-4 085 359), in which the collector current of one transistor of the reference voltage source is mirrored on the collector current of the other transistor, and the emitter areas of the transistors and the resistance values are defined in this way that the reference voltage is largely independent of the temperature.

Die Erfindung geht nun von der Aufgabe aus, die Ausnutzbarkeit solcher Referenzspannungsquellen zu verbessern. Die Verbeserung betrifft insbesondere Maßnahmen, die sicherstellen, daß die Referenzspannung unabhängig von der Belastung ihre vorgesehene Größe beibehält. Bei der Erfindung wird dabei von einer Referenzspannungsquelle gemäß dem Oberbegriff des Anspruchs 1 ausgegangen, bei der die Referenzspannung an den miteinander verbundenen Basen zweier Transistoren ansteht, von denen einer als Diode geschaltet ist, während der andere normal betrieben ist.The invention is based on the object of improving the usability of such reference voltage sources. The improvement relates in particular to measures which ensure that the reference voltage maintains its intended size regardless of the load. In the invention, a reference voltage source is assumed in which the reference voltage is present at the interconnected bases of two transistors, one of which is connected as a diode, while the other is operated normally.

Gemäß der Erfindung ist eine derartige Referenzspannungsquelle dadurch gekennzeichnet, daß zu der Stromspiegelschaltung eine weiterer in Stromspiegelschaltung angeschlossener Transistor gehört, der in Reihe mit einem an Bezugspotential gelegten entsprechenden Transistor geschaltet ist, dessen Basis mit dem Emitter des als Diode geschalteten Transistors verbunden ist und dab die Referenzspannung am Verbindungspunkt zwischen Kollektor und Emitter der in Reihe geschalteten Transistoren für eine damit zu beliefernde Schaltung abgenommen wird. Hierbei kommen Stromspiegelschaltungen infrage, wie sie an sich bekannt sind (siehe DE-A-24 40 023, 26 42 874; Philips Technische Rundschau 1971/72, Nr. 1, Seiten 4 bis 8; Regelungstechnik, Haft 1, 1969, Seite 13). Dadurch, daß die Referenzspannung an einem Abgriff der Reihenschaltung der beiden betreffenden Transistoren abgenommen wird, wird eine Belastung des inneren Referenzschaltungspunktes der Referenzspannungsquelle vermieden, auch wenn der Abgriff als Stromquelle bzw. Stromsenke für die Stabilisierung des Arbeitspunktes der belieferten Schaltung ausgenutzt wird. Damit ist eine besonders große Konstanz der Referenzspannung sichergestellt. Vorteilhaft ist auch, daß der Spannungsbedarf für die Referenzspannungsquelle sehr klein ist. Ihre minimale Betriebsspannung liegt nur um die Sättigungsspannung des Transistors T6 über des an der Basis des Transistors T2 anliegenden Referenzspannung.According to the invention, such a reference voltage source is characterized in that the current mirror circuit includes a further transistor connected in a current mirror circuit, which is connected in series with a corresponding transistor connected to reference potential, the base of which is connected to the emitter of the transistor connected as a diode, and dab the The reference voltage at the connection point between the collector and emitter of the transistors connected in series for a circuit to be supplied is taken off. Current mirror circuits as are known per se can be used here (see DE-A-24 40 023, 26 42 874; Philips Technische Rundschau 1971/72, No. 1, pages 4 to 8; Regelstechnik, Haft 1, 1969, page 13 ). Because the reference voltage is taken from a tap of the series connection of the two transistors in question, a load on the inner reference circuit point of the reference voltage source is avoided, even if the tap is used as a current source or current sink for stabilizing the operating point of the circuit supplied. This ensures a particularly high constancy of the reference voltage. It is also advantageous that the voltage requirement for the reference voltage source is very small. Their minimum operating voltage is only above the saturation voltage of transistor T6 above the reference voltage applied to the base of transistor T2.

Eine zweckmäßige weitere Ausgestaltung der Referenzspannungsquelle ergibt sich, wenn zur Stromspiegelschaltung eine zusätzlicher Transistor gehört, der eine weitere Stromspiegelschaltung speist, welche Transistoren hat, die in Stromkreise der mit der Referenzspannung belieferten Schaltung eingeschleift sind. Dadurch werden in bequemer Weise Konstantstromeffekte für die belieferte Schaltung zustande gebracht.An expedient further embodiment of the reference voltage source is obtained if the current mirror circuit includes an additional transistor which feeds a further current mirror circuit which has transistors which are looped into circuits of the circuit supplied with the reference voltage. Constant current effects for the supplied circuit are thereby brought about in a convenient manner.

Die vorstehend angegebenen Effekte werden nun noch an einem Beispiel für eine Referenzspannungsquelle und eine damit belieferte Schaltung anhand der Figur näher erläutert. In dieser Figur ist die Referenzspannungsquelle RG und die Verstärkerschaltung VS gezeigt. Der Eingang der Verstärkerschaltung VS liegt bei den Klemmen E1 und E2. Der Ausgang liegt bei den Quellen A3 und A4. Bei dieser Verstärkerschaltung handelt es sich um einen Mikrofonverstärker. Der akustisch-elektrische Wandler, insbesondere eine Piezoelektrische Keramik, ist bei den Eingangsklemmen E1 und E2 angeschlossen. Über die Ausgangsklemmen A3 und A4 wird die Betriebsspannung +/0 zugeführt, der dann das Ausgangssignal überlagert ist. An die Eingangsklemme E1 ist nun noch die von der Referenzspannungsquelle RG gelieferte Referenzspannung angelegt. Mit Ihrer Hilfe wird der Arbeitspunkt des Differenzverstärkers mit den Transistoren T13 und T14, der zur Verstärkerschaltung gehört, stabilisiert.The effects specified above will now be explained in more detail using an example of a reference voltage source and a circuit supplied with it using the figure. In this figure, the reference voltage source RG and the amplifier circuit VS are shown. The input of the amplifier circuit VS is at the terminals E1 and E2. The output is at sources A3 and A4. This amplifier circuit is a microphone amplifier. The acoustic-electrical converter, in particular a piezoelectric ceramic, is connected to the input terminals E1 and E2. The operating voltage + / 0 is supplied via the output terminals A3 and A4, which is then superimposed on the output signal. The reference voltage supplied by the reference voltage source RG is now also applied to the input terminal E1. With your help, the operating point of the differential amplifier with the transistors T13 and T14, which belongs to the amplifier circuit, is stabilized.

Zur Referenzspannungsquelle selber gehören zunächst der als Diode geschaltete Transistor T2 und der normal betriebene Transistor T1. Die Basen dieser beiden Transistoren sind verbunden und ergeben den inneren Referenzspannungspunkt. In die Kollektorstromkreise der Transistoren T1 und T2 ist die Stromspiegelschaltung mit den Transistoren T4 und T5 sowie den Widerständen R1 und R2 eingeschleift. Es gehört noch der Transistor T6 mit dem Widerstand R3 dazu, der in Reihe zu dem Transistor T8 geschaltet ist, der noch an Bezugspotential 0 gelegt ist. Die Basis des Transistors T8 ist mit dem Emitter des Transistors T2 und mit dem Abgriff der Reihenschaltung aus den Emitterwiderständen R6 und R7 verbunden, die als Emitterwiderstände für die Transistoren T1 und T2 dienen. Der Verbindungspunkt zwischen dem Kollektor des Transistors T6 und dem Emitter des Transistors T8 ist mit der Eingangsklemme E1 verbunden. Hier wird also die Referenzspannung für die damit belieferte Schaltung VS abgenommen. Die Höhe der Referenzspannung selbar wird zwar durch die am inneren Referenzspannungspunkt, nämlich den verbundenen Basen der Transistoren T1 und T2, liegenden Spannung bestimmt. Mit Hilfe der durch die Transistoren T8 und T6 gebildeten Ausgangsschaltung wird jedoch verhindert, daß dieser innere Referenzspannungspunkt durch das Abnehmen der Referenzspannung belastet wird. Bei der Lieferung der Referenzspannung können hier die zur Ausgangsschaltung gehörenden Transistoren T6 und T8 als Stromquelle bzw. Stromsenke wirken. Eine Belastung des inneren Referenzspannungspunktes ist während des Betriebes vermieden.The reference voltage source itself initially includes the transistor T2 connected as a diode and the normally operated transistor T1. The bases of these two transistors are connected and give the inner reference voltage point. The current mirror circuit with the transistors T4 and T5 and the resistors R1 and R2 is looped into the collector circuits of the transistors T1 and T2. It also includes the transistor T6 with the resistor R3, which is connected in series with the transistor T8, which is still connected to the reference potential 0. The base of transistor T8 is connected to the emitter of transistor T2 and to the tap of the series circuit made up of emitter resistors R6 and R7, which serve as emitter resistors for transistors T1 and T2. The connection point between the collector of transistor T6 and the The emitter of the transistor T8 is connected to the input terminal E1. So here the reference voltage for the circuit VS supplied with it is taken off. The level of the reference voltage is selectively determined by the voltage at the inner reference voltage point, namely the connected bases of the transistors T1 and T2. With the aid of the output circuit formed by the transistors T8 and T6, however, this inner reference voltage point is prevented from being loaded by the decrease in the reference voltage. When the reference voltage is supplied, the transistors T6 and T8 belonging to the output circuit can act as a current source or current sink. A load on the inner reference voltage point is avoided during operation.

Die Referenzspannungsquelle RG ist noch durch die Anlaßschaltung aus der Reihenschaltung des Transistors T3 und seines Emitterwiderstandes R5 ergänzt. An diese Anlaßschaltung ist die Betriebsspannung +/0 angelegt. Die Basis des Transistors T3 ist mit dem Kollektor des Transistors T1 verbunden Hierdurch ist sichergestellt, daß beim Anlegen der Betriebsspannung sich am inneren Referenzschaltungspunkt die vorgesehene Referenzspannung einstellt.The reference voltage source RG is supplemented by the starting circuit comprising the series circuit of the transistor T3 and its emitter resistor R5. The operating voltage + / 0 is applied to this starting circuit. The base of the transistor T3 is connected to the collector of the transistor T1. This ensures that when the operating voltage is applied, the intended reference voltage is set at the inner reference circuit point.

Bei der Referenzspannungsquelle RG ist die Fläche des Emitters des als Diode geschalteten Transistors T2 ein Bruchteil der Fläche des Emitters des anderen zugehörigen Transistors T1. Hierdurch und durch die weiteren vorgesehenen Schaltungsmaßnahmen ergibt sich eine Temperaturkompensation insofern, als dadurch die erzielte Referenzspannung weitgehend unabhängig von der Temperatur ist (siehe auch Regelungstechnik, Heft 1, 1969, Seite 13; DE-B-19 440 28, Spalte 1 ). Bei dem in der Figur gezeigten Schaltungsbeispiel ist die Fläche des Emitters des Transistors T1 fünfmal so groß wie die Fläche des Emitters des Transistors T2. Dies ist dort auch durch die eingeschrieben Ziffern 5 und 1 angedeutet. Bei den verschiedenen zur Schaltung gehörenden Widerständen ist auch jeweils die Ohmzahl angeschrieben. Für die Temperaturkompensation ist auch das Verhältnis der Widerstandswerte der Emitterwiderstände R6 und R7 von Bedeutung. Anhand der für die Darstellung der Transistoren gewählten Symbole ist auch erkennbar, ob es sich jeweils um einen pnp-Transistor oder um einen npn-Transistor handelt.In the case of the reference voltage source RG, the area of the emitter of the transistor T2 connected as a diode is a fraction of the area of the emitter of the other associated transistor T1. This and the additional circuit measures provided result in temperature compensation insofar as the reference voltage obtained is largely independent of the temperature (see also Control Technology, Issue 1, 1969, page 13; DE-B-19 440 28, column 1). In the circuit example shown in the figure, the area of the emitter of transistor T1 is five times the area of the emitter of transistor T2. This is also indicated there by the inscribed numbers 5 and 1. The number of ohms is also written for each of the various resistors belonging to the circuit. The ratio of the resistance values of the emitter resistors R6 and R7 is also important for the temperature compensation. On the basis of the symbols chosen for the representation of the transistors, it can also be recognized whether it is a pnp transistor or an npn transistor.

Wie bereits erwähnt, gehört zur Stromspiegelschaltung noch ein zusätzlicher Transistor, und zwar der Transistor T7 mit einem Emitterwiderstand R4, der eine weitere Stromspiegelschaltung speist. Dabei handelt es sich um die Stromspiegelschaltung mit den Transistoren T9, T10, T11, T12 und T19. Die letzten drei angeführten Transistoren sind in Stromkreise der mit der Referenzspannung belieferten Verstärkerschaltung VS eingeschleift. So ist der Transistor T11 1 in den Emitterstromkreis des Differenzverstärkers mit den Transistoren T13 und T14, den Emitterwiderständen R12 und R13 sowie den Kollektorwiderständen R8 und R9 eingeschleift. Der Transistor T12 ist in den Hauptstromkreis des Transistors T20 eingeschleift, der zu einem Zwischenverstärker der Verstärkerschaltung VS gehört. Der Transistor T19 ist in einen Stromzweig einer zur Verstärkerschaltung gehörenden Stromspiegelschaltung eingeschleift, zu der u.a. die Transistoren T17, T18 und T22 sowie die Widerstände R20 und R22 gehören. Durch diese Schaltungstechnik wird eine bestimmte Stromeinprägung für die Verstärkerschaltung erzielt, wozu Schaltmittel verwendet sind, die sich bequem an die zur Referenzspannungsquelle gehörenden Schmaltmittel anfügen lassen. Auch bei den hierfür in Betracht kommenden Transistoren ist jeweils die Größe der zugehörenden Emitterflächen durch angeschriebene Ziffern angedeutet. So ist, bei den Transistoren T7, T10 und T19 die Ziffer 1 angeschrieben, während bei den Transistoren T11 und T12 die Ziffer 2 angeschrieben ist. Dementsprechend führen die beiden zuletzt genannten Transistoren einen doppelt so großen Hauptstrom als die in diesem Zusammenhang genannten anderen drei Transistoren. Es ist übrigens auch bei den übrigen zur Stromspiegelschaltung des Referenzspannungsgebers RG gehörenden Transistoren T4, T5 und T6 die Größe des Emitterflächen durch angeschriebene Ziffern angegeben. Demnach hat der Transistor T6 eine dreimal so große Emitterfläche als die Transistoren T1 und T5. Die Stärke der über die Hauptstromstrecken der genannten Transistoren fließenden Ströme ist entsprechend der Größe ihrer Emitterflächen gstuft. Dementsprechend ist auch die Stärke der in denjenigen Stromkreisen fließenden Ströme gestuft, in welche diese Transistoren eingeschleift sind.As already mentioned, an additional transistor belongs to the current mirror circuit, namely the transistor T7 with an emitter resistor R4, which feeds a further current mirror circuit. This is the current mirror circuit with transistors T9, T10, T11, T12 and T19. The last three listed transistors are looped into circuits of the amplifier circuit VS supplied with the reference voltage. The transistor T11 1 is looped into the emitter circuit of the differential amplifier with the transistors T13 and T14, the emitter resistors R12 and R13 and the collector resistors R8 and R9. The transistor T12 is looped into the main circuit of the transistor T20, which belongs to an intermediate amplifier of the amplifier circuit VS. The transistor T19 is looped into a current branch of a current mirror circuit belonging to the amplifier circuit, to which i.a. the transistors T17, T18 and T22 and the resistors R20 and R22 belong. This circuit technology achieves a specific current impression for the amplifier circuit, for which purpose switching means are used which can be conveniently attached to the switching means belonging to the reference voltage source. In the case of the transistors that are considered for this, the size of the associated emitter areas is indicated by the numbers written on them. Thus, the number 1 is written on the transistors T7, T10 and T19, while the number 2 is written on the transistors T11 and T12. Accordingly, the two latter transistors carry a main current twice as large as the other three transistors mentioned in this context. Incidentally, in the case of the other transistors T4, T5 and T6 belonging to the current mirror circuit of the reference voltage transmitter RG, the size of the emitter areas is indicated by the numbers written on them. Accordingly, the transistor T6 has an emitter area three times as large as the transistors T1 and T5. The strength of the currents flowing across the main current paths of the named transistors is graded according to the size of their emitter areas. Accordingly, the strength of the currents flowing in those circuits into which these transistors are looped is graded.

Zu der Verstärkerschaltung VS gehören außer dem bereits erwähnten Differenzverstärker mit den Transistoren T13 und T14 und der ebenfalls bereits erwähnten Stromspiegelschaltung mit den Transistoren T17, T18 und T22 noch die symmetrisch geschaltete Transistorkoppelstufe mit den Transistoren T15 und T16, über die der Differenzverstärker mit einem zweistufigen Zwischenverstärker verbunden ist, zu dem die Transistoren T20 und T21 gehören, an denen dann als Ausgangsstufe ein Darlington-Verstärker mit den Transistoren T23 und T24 angeschlossen ist. Die Transistoren T15 5 und T16 der Transistorkoppelstufe gehören auch zur Stromspiegelschaltung mit den Transistoren T17 und T18. Dadurch und mit Hilfe der zusätzlichen Stromspiegelschaltung mit den Transistoren T25 und T26 und den Widerständen R24 und R25 sowie der bereits erwähnten Stromspiegelschaltung mit den Transistoren T9, T10, T11, T12 und T19, sind die Koppelstufe und die Eingangsstufe stromsymmetrisch eingestellt. Dadurch wird eine besonders stabile Arbeitsweise der Verstärkerschaltung erzielt. Es zeigt sich auch, daß dadurch die Verstärkereigenschaften wenig von den Speisebedingungen der Schaltung abhängig sind. Wegen des sehr geringen Spannungsbedarfes der Verstärkerschaltung und der übrigen günstigen Eigenschaften ergibt sich auch eine sehr große Aussteuerfähigkeit der Verstärkerschaltung. Zwischen dem Ausgang und dem Eingang ist noch das Spannungsgegenkopplungsnetzwerk mit den Widerständen R19, R18, R15, R17, R16, R14, R11 und R10 eingefügt. Mit seiner Hilfe wird unteranderem der Verstärkungsfaktor der Verstärkerschaltung festgelegt (siehe auch Siemens-Datenbuch 1974/75, Bad 2, "Lineare Schaltungen", Seiten 213 bis 215). Bei der Stabilisierung wirkt dann noch der Gegenkopplungskondensator C1 mit. Die Transistoren T23 und T24 der Ausgangsstufe haben jeweils eigene Kollektorwiderstände, nämlich die Kollektorwiderstände R21 und RL. Hierdurch ergibt sich eine besonders große Aussteuerfähigkeit der Ausgangsstufe und ein niedrige Sättigungspannung des Transistores T24. In der Figur sind Schließlich noch mit "lK" bzw. mit "21K" bezeichnete Pfeile eingezeichnet, welche die Richtung und die Größe der in den betreffenden Stromzweigen fließenden Ströme angeben. Diese Ströme ergeben sich vor allem dadurch, daß die beschriebenen Stromspiegelschaltungen vorgesehen sind.In addition to the already mentioned differential amplifier with transistors T13 and T14 and the already mentioned current mirror circuit with transistors T17, T18 and T22, the amplifier circuit VS also includes the symmetrically switched transistor coupling stage with transistors T15 and T16, via which the differential amplifier has a two-stage intermediate amplifier is connected, to which the transistors T20 and T21 belong, to which a Darlington amplifier with the transistors T23 and T24 is then connected as an output stage. The transistors T15 5 and T16 of the transistor coupling stage also belong to the current mirror circuit with the transistors T17 and T18. As a result, and with the help of the additional current mirror circuit with the transistors T25 and T26 and the resistors R24 and R25 and the already mentioned current mirror circuit with the transistors T9, T10, T11, T12 and T19, the coupling stage and the input stage are set in a current-symmetrical manner. This makes the amplifier work in a particularly stable manner circuit achieved. It also shows that the amplifier properties are not very dependent on the supply conditions of the circuit. Because of the very low voltage requirement of the amplifier circuit and the other favorable properties, the amplifier circuit also has a very high modulation capability. The voltage feedback network with the resistors R19, R18, R15, R17, R16, R14, R11 and R10 is also inserted between the output and the input. With its help, among other things, the gain factor of the amplifier circuit is determined (see also Siemens data book 1974/75, Bad 2, "Linear circuits", pages 213 to 215). The negative feedback capacitor C1 then also contributes to the stabilization. The transistors T23 and T24 of the output stage each have their own collector resistors, namely the collector resistors R21 and RL. This results in a particularly high modulation capability of the output stage and a low saturation voltage of the transistor T24. Finally, in the figure, arrows labeled “lK” or “21K” are drawn, which indicate the direction and the size of the currents flowing in the relevant current branches. These currents result primarily from the fact that the current mirror circuits described are provided.

Der vorstehend beschriebene Mikrofonverstärker ist auch derart schaltungstechnisch ausgestaltet, daß er sich bequem innerhalb einer integrierten Schaltung realisieren läßt. Seine vorteilhaften Eigenschaften bleiben dabei erhalten.The microphone amplifier described above is also designed in terms of circuit technology in such a way that it can be easily implemented within an integrated circuit. Its advantageous properties are retained.

Claims (4)

1. A reference voltage source, in particular for amplifier circuits, wherein the reference voltage is applied to the mutually connected base electrodes of two transistors (T1, T2), one (T2) of which is connected as a diode and the other one (T1) of which is normally connected, and where the emitter electrode of the transistor (T2) which is connected as a diode is connected to a tapping formed by the junction of two series connected resistors (R6, R7) in the emitter path of the normally operated transistor (T1), and wherein furthermore a current reflector circuit (T4, T5, R1, R2) is so looped into the collector circuits of these transistors that the collector current of the normally operated transistor (T1) is reflected onto the collector current of the transistor (T2) which is connected as a diode, and wherein furthermore the emitter surfaces of the transistors and the resistance values of the emitter resistors are so determined that the reference voltage is largely independent of temperature, characterised in that the current reflector circuit (T4, T5, R1, R2) is assigned a further transistor (T6) in a current reflector circuit connected to the reference potential (0) in series with a corresponding transistor (T8) whose base electrode is connected to the emitter electrode of the transistor (T2) which is connected as a diode, and that the connection point between the collector and emitter electrodes of the series-connected transistors (T6, T8) provides the reference voltage tapping for a circuit (VS) which is to be supplied therewith.
2. A reference voltage source as claimed in Claim 1, characterised in that there is provided a starting-up circuit composed of the series connection of a transistor (T3) and its emitter resistor (R5), to which starting-up circuit is connected the operating voltage (+/0), and that the base electrode of the assigned transistor (T3) is connected to the collector electrode of said normally operated transistor (T1
3. A reference voltage source as claimed in one of the preceding Claims, characterised in that the current reflector circuit is assigned an additional transistor (T7) which feeds a further current reflector circuit (T9, T10, T11, T12, T19) which has transistors (T11, T12, T19) looped into circuit paths of the circuit (VS) which is supplied with the reference voltage.
4. A reference voltage source as claimed in Claim 4, characterised in that the intensity of the currents flowing in said circuit paths are graded in accordance with the size of the emitter surfaces of the transistors (T11, T12, T19) of the further current reflector circuit which are looped into these circuit paths.
EP79104039A 1978-11-23 1979-10-18 Voltage reference source, in particular for amplifier circuits Expired EP0011704B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2850826 1978-11-23
DE19782850826 DE2850826A1 (en) 1978-11-23 1978-11-23 REFERENCE VOLTAGE SOURCE, IN PARTICULAR FOR AMPLIFIER CIRCUITS

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EP0011704A1 EP0011704A1 (en) 1980-06-11
EP0011704B1 true EP0011704B1 (en) 1983-07-13

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US (1) US4274061A (en)
EP (1) EP0011704B1 (en)
JP (1) JPS5574616A (en)
DE (2) DE2850826A1 (en)
MY (1) MY8700876A (en)

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Publication number Priority date Publication date Assignee Title
US4368420A (en) * 1981-04-14 1983-01-11 Fairchild Camera And Instrument Corp. Supply voltage sense amplifier
US4359680A (en) * 1981-05-18 1982-11-16 Mostek Corporation Reference voltage circuit
IT1212748B (en) * 1983-06-03 1989-11-30 Ates Componenti Elettron IMPROVED DIFFERENTIAL STAGE, IN PARTICULAR FOR ACTIVE FILTERS.
US4578820A (en) * 1984-03-05 1986-03-25 General Electric Company Received signal strength indicator
US4820967A (en) * 1988-02-02 1989-04-11 National Semiconductor Corporation BiCMOS voltage reference generator
US4816742A (en) * 1988-02-16 1989-03-28 North American Philips Corporation, Signetics Division Stabilized current and voltage reference sources
US4929909A (en) * 1989-03-27 1990-05-29 Analog Devices, Inc. Differential amplifier with gain compensation
US5345185A (en) * 1992-04-14 1994-09-06 Analog Devices, Inc. Logarithmic amplifier gain stage
US5436595A (en) * 1994-08-01 1995-07-25 Hewlett-Packard Company Low voltage bipolar amplifier

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Publication number Priority date Publication date Assignee Title
DE1762924B1 (en) * 1968-09-24 1970-09-03 Siemens Ag Circuit arrangement for a telephone microphone amplifier with an amplifier output side feed
US3629691A (en) * 1970-07-13 1971-12-21 Rca Corp Current source
DE2412393C3 (en) * 1973-03-20 1979-02-08 N.V. Philips' Gloeilampenfabrieken, Eindhoven (Niederlande) Current stabilization circuit
NL7403202A (en) * 1974-03-11 1975-09-15 Philips Nv POWER STABILIZATION CIRCUIT.
NL7409851A (en) * 1974-07-22 1976-01-26 Philips Nv AMPLIFIER CIRCUIT.
FR2345761A1 (en) * 1976-03-26 1977-10-21 Radiotechnique Compelec Constant current circuit feeding integrated unit - uses varying voltage source with min. dissipation and coupling between parallel current divider paths
US4085359A (en) * 1976-02-03 1978-04-18 Rca Corporation Self-starting amplifier circuit

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EP0011704A1 (en) 1980-06-11
DE2850826A1 (en) 1980-06-04
MY8700876A (en) 1987-12-31
JPS5574616A (en) 1980-06-05
US4274061A (en) 1981-06-16
DE2965866D1 (en) 1983-08-18

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