WO1985004294A1 - Linear amplifier circuit for direct current and alternating current - Google Patents

Linear amplifier circuit for direct current and alternating current Download PDF

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Publication number
WO1985004294A1
WO1985004294A1 PCT/DE1985/000077 DE8500077W WO8504294A1 WO 1985004294 A1 WO1985004294 A1 WO 1985004294A1 DE 8500077 W DE8500077 W DE 8500077W WO 8504294 A1 WO8504294 A1 WO 8504294A1
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WO
WIPO (PCT)
Prior art keywords
voltage
amplifier
transistors
output
current
Prior art date
Application number
PCT/DE1985/000077
Other languages
German (de)
French (fr)
Inventor
Joachim Rieder
Original Assignee
Joachim Rieder
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 Joachim Rieder filed Critical Joachim Rieder
Publication of WO1985004294A1 publication Critical patent/WO1985004294A1/en

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/30—Single-ended push-pull [SEPP] amplifiers; Phase-splitters therefor
    • H03F3/3066—Single-ended push-pull [SEPP] amplifiers; Phase-splitters therefor the collectors of complementary power transistors being connected to the output
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/30—Indexing scheme relating to single-ended push-pull [SEPP]; Phase-splitters therefor
    • H03F2203/30051—Indexing scheme relating to single-ended push-pull [SEPP]; Phase-splitters therefor the SEPP amplifying transistors are composed of multiple coupled transistors
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/30—Indexing scheme relating to single-ended push-pull [SEPP]; Phase-splitters therefor
    • H03F2203/30069—A SEPP amplifier with a reactive element in the bias circuit
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/45—Indexing scheme relating to differential amplifiers
    • H03F2203/45136—One differential amplifier in IC-block form being shown
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2203/00—Indexing scheme relating to amplifiers with only discharge tubes or only semiconductor devices as amplifying elements covered by H03F3/00
    • H03F2203/45—Indexing scheme relating to differential amplifiers
    • H03F2203/45166—Only one input of the dif amp being used for an input signal

Abstract

The principles of "linear amplifier circuits for direct current and alternating current" have been known for a long time and are partly derived from the valve techniques. The type which is most commonly used at present comprises a differential input and a final push-pull stage and operates with a counter-coupling. The final transistors operate usually as emitter-followers at the dynamic operation point A-B. This principle requires that the voltage amplifier reaches the voltage amplitude of the output voltage. In the new "linear amplifier circuit for direct current and alternating current", the final transistors (T3, T4) operate as a common emitter at the dynamic operation point B-C and the currents thereof are coupled. The voltage amplitude of the voltage amplifier (OP) has no importance since said voltage allows only the flow of a current to zero. Said current, however, flows from the positive or negative side in the voltage amplifier (OP) and simultaneously controls the final transistors (T3, T4). In case of a small signal or without the latter, the output voltage (U-aus) is generated by two pretransistors (T1, T2). These also operate as a common emitter and their currents are also coupled. The output voltage is obtained from the difference of the collector currents of the push-pull transistors (T1, T2, T3, T4). Said voltage is counter-coupled to the differential input amplifier (OP) and is thus adjusted at a fixed ratio to the input voltage. As the voltage amplitude is smaller at the output (U-aus) of the voltage amplifier (OP) than the input voltage, its open loop amplifier is exclusively used to compensate for the non-linearities of the amplifier. Even the output load has no influence on the output voltage. As the voltage amplitude of the voltage amplifier is only a few volts, the voltage amplifier may be a conventional operational amplifier which is commercially available, even in the case where the output voltage of the final stage is high. Due to the dynamic operation point B-C of the final transistors (T3, T4), the ratio between the output power and the dissipated power is very advantageous, of the order of 3/1. This new principle enables the construction of better linear amplifiers with a reduced number of component parts.

Description

Lineare Gleichstrom-Wechselstrom-Verstärker-Schaltung. Linear DC-AC amplifier circuit.
A n w e n d u n g s g e b i e t :Field of use :
Die Erfindung betrifft eine Verstärkerschaltung,wie sie auf vielen Gebieten der Technik benötigt wird. Zum Beispiel in der Regeltechnik und zur Tonfrequenzverstärkung.The invention relates to an amplifier circuit, as is required in many fields of technology. For example in control technology and audio frequency amplification.
Z w e c k:Z w e c k:
Zweck ist die lineare Verstärkung von fast leistungslosen kleinen Spannungen oder Strömen in Spannungen und Ströme, mit denen ein Arbeitsprozess ausgeführt werden kann.The purpose is the linear amplification of almost powerless small voltages or currents in voltages and currents with which a work process can be carried out.
S t a n d d e r T e c h n i k u n d K r i t i k : Bei derartigen Verstärkern war bisher, je nach erforderlicher Linearität, eine große Zahl von Bauteilen erforderlich.Und bei der Herstellung waren mitunder erhebliche Abgleicharbeiten an den fertigen Verstärkern erforderlich. Auch die Langzeitstabilität der vorgegebenen Werte brachte oft Probleme.S t a n d e r T e c h n i k u n d K r i t i k: With amplifiers of this type, depending on the required linearity, a large number of components have been required up to now. The long-term stability of the specified values also often caused problems.
A u f g a b e :A f g a b e:
Mit der Erfindung soll erreicht werden, daß hochwertige Verstärker mit relativ einfachen Mitteln und wenig Arbeitsaufwand auch in kleinen Stückzahlen produziert werden können. Der Verstärker soll auch alterungsbedingte Veränderungen der Bauteilwerte kompensieren, so daß die vorgegebenen Werte auch über lange Zeit erhalten bleiben. The aim of the invention is that high-quality amplifiers can be produced with relatively simple means and little work, even in small quantities. The amplifier is also intended to compensate for age-related changes in the component values, so that the specified values are retained even over a long period.
L ö s u n g :SOLUTION:
Die Aufgabe wird erfindungsmäßig dadurch gelöst, daß die Ausgangsspannung des in solchen Verstärkern benützten Differenzspannungsverstärkers nicht zum Ansteuern von zwei Transistoren in Emitterfolger-Schaltung verwendet wird, sondern so,wie es im Ausführungsbeispiel beschrieben ist.The object is achieved according to the invention in that the output voltage of the differential voltage amplifier used in such amplifiers is not used for driving two transistors in an emitter-follower circuit, but rather as described in the exemplary embodiment.
E r z i e l b a r e V o r t e i l e : 1) Die beiden Leistungstransistoren können spannungsmäßig beliebig weit auseinander liegen, ohne daß der OP an seinem Ausgang diese Spannung liefern muß. 2) Der in 1) erklärte Vorteil ermöglicht die Verwendung eines handelsüblichen integrierten OP.E r z i e l b a r e V o r t e i l e: 1) The voltage of the two power transistors can be as far apart as required without the OP having to supply this voltage at its output. 2) The advantage explained in 1) enables the use of a commercially available integrated OR.
3) Durch die starke Gegenkopplung, die erst durch die Verwendung eines OP möglich wird,werden alle Bauteildifferenzen und Nichtlinearitäten kompensiert. 4) Wegen der hervorragenden Kompensation können die eigentlichen Leistungstransistoren im B-C Arbeitspunkt betrieben werden.3) The strong negative feedback, which is only possible through the use of an OP, compensates for all component differences and non-linearities. 4) Because of the excellent compensation, the actual power transistors can be operated at the B-C operating point.
5) Der in 4) erklärte Vorteil ermöglicht die problemlose Paralleelschaltung mehrerer Trasistoren.5) The advantage explained in 4) enables problem-free parallel connection of several trasistors.
6) Durch die Verwendung eines IC-OP verringern sich die Bauteile ganz erheblich und die Schaltung ist wesenlich einfacher.6) By using an IC-OP, the components are reduced considerably and the circuit is essentially easier.
7) Wegen der starken Gegenkopplung werden Störspannungen unterdrückt.7) Due to the strong negative feedback, interference voltages are suppressed.
8)Weil effektiv keine Spannungsverstärkung stattfindet, ist der Rauschspannungsabstand hervorragend. 8) Because there is effectively no voltage amplification, the signal-to-noise ratio is excellent.
A u s f ü h r u n g s b e i s p i e l :A u s r u n g s b e i s p i e l:
Die Eingangsspannung U-ein wird im Differenzspannungsverstärker, im Folgenden OP genannt, verarbeitet. Die Ausgangsspannung des OP ist kein Nutzsignal und wegen der Gegenkopplung und Stromverstärkung von T1-T2-T3-T4 in der Regel kleiner als U-ein. Diese Spannung verursacht in R1 einen von U-ein und U-aus abhängigen Strom.Dieser fließt über R2 oder R3 zum OP, in Abhängigkeit von der Spannung an R1, je nachdem,ob diese positiv oder negativ ist. Über diese Widerstände fließt auch der Ruhestrom des OP.Der Ruhestrom- Spannungsabfall an R2 und R3 ist gleich groß und bestimmt den Ruhestrom von T1 und T2 in Verbindung mit R4 und R5. Der Spannungsabfall an R2 und R3 wird in Abhängigkeit vom Ruhestrom des OP durch diese Widerstände so eingestellt, daß der Spannungsabfall an R4 und R5 deutlich unter der Schwellspannung der Basis-Emitter-Diode von T3 und T4 liegt. Diese Transistoren arbeiten im B-C Arbeitspunkt. Die Widerstände R4 und R5 bestimmen den Ruhestrom und stabilisieren den Arbeitspunkt von T1 und T2. Diese Transistoren arbeiten im A-B Arbeitspunkt und übernehmen den Laststrom bei kleiner Aussteuerung.Der Verstärker arbeitet jedoch,wenn nur der A-B Arbeitspunkt erwünscht ist, auch ohne T3 und T4. Durch die Rückführung von U-aus, die von T1-T2-T3-T4 erzeugt wird, über R6 und R7 oder direkt an den invertierenden Eingang des OP erfolgt eine starke Gegenkopplung und ein festes Verhältniss zwischen U-ein und U-aus. Durch die Gegenkopplung werden Bauteildifferenzen und Nichtlinearitäten kompensiert.Deshalb ist auch der Knick in der Stromverstärkung, der beim Übergang von T1-T2 auf T3-T4 entsteht,unwirksam. Da die unsymetrischen Spannungsschwankungen, die an R2 und R3 entstehen,und auch aus der Versorgungsspannung kommen, sich negativ auf den OP auswirken, sind T5 und T6 als positiv-und negativ- Spannungsregler geschaltet. Der Kondensator lädt sich beim Einschalten des Verstärkers nur langsam auf,was eine Einschaltverzögerung für U-aus bewirkt. Beim Ausschalten kann sich der Kondensator schnell über T5 und T6 entladen. The input voltage U-in is processed in the differential voltage amplifier, hereinafter referred to as OP. The output voltage of the OP is not a useful signal and, due to the negative feedback and current amplification of T1-T2-T3-T4, is usually less than U-on. This voltage causes a current dependent on U-in and U-out in R1, which flows via R2 or R3 to the OP, depending on the voltage at R1, depending on whether it is positive or negative. The quiescent current of the OP also flows through these resistors. The quiescent current voltage drop across R2 and R3 is the same and determines the quiescent current of T1 and T2 in conjunction with R4 and R5. The voltage drop across R2 and R3 is adjusted depending on the quiescent current of the OP through these resistors so that the voltage drop across R4 and R5 is significantly below the threshold voltage of the base-emitter diode of T3 and T4. These transistors operate at the B-C operating point. The resistors R4 and R5 determine the quiescent current and stabilize the operating point of T1 and T2. These transistors work at the A-B operating point and take over the load current with a small modulation. However, if only the A-B operating point is desired, the amplifier also works without T3 and T4. The feedback of U-out, which is generated by T1-T2-T3-T4, via R6 and R7 or directly to the inverting input of the OP results in a strong negative feedback and a fixed relationship between U-in and U-out. Component differences and non-linearities are compensated by the negative feedback, which is why the kink in the current amplification that occurs during the transition from T1-T2 to T3-T4 is also ineffective. Since the asymmetrical voltage fluctuations that arise at R2 and R3 and also come from the supply voltage have a negative effect on the OP, T5 and T6 are connected as positive and negative voltage regulators. The capacitor charges only slowly when the amplifier is switched on, which causes a switch-on delay for U-off. When switched off, the capacitor can quickly discharge via T5 and T6.

Claims

P a t e n t a n s p r u c h :P a t e n t a n s r u c h:
Lineare Gleichstrom-Wechselstrom-Verstärker-Schaltung, dadurch gekennzeichnet, daß die in einem Differenzspannungsverstärker erzeugte Ausgangsspannung nicht die Endtransistoren steuert, sondern über einen Lastwiderstand am Ausgang und je einen Vorwiderstand in der positiven und negativen Versorgunsleitung des Differenzspannungsverstärkers in zwei Ströme und Spannungen umgewandelt wird.Diese steuern die Endtransistoren in Emitterschaltung.Linear DC-AC amplifier circuit, characterized in that the output voltage generated in a differential voltage amplifier does not control the end transistors, but is converted into two currents and voltages via a load resistor at the output and a series resistor in the positive and negative supply line of the differential voltage amplifier. These control the end transistors in an emitter circuit.
Unteranspruch 1:Subclaim 1:
Spannungsversorgung des Differenzspannungsverstärkers, dadurch gekennzeichnet, daß über je einen positiven und negativen Spannungsregler die durch den Lastwiderstand fließenden Ströme auch durch die Vorwiderstände fließen, die daraus resultierenden Spannungsschwankungen jedoch nicht am Differenzspannungsverstärker anstehen.Power supply to the differential voltage amplifier, characterized in that the currents flowing through the load resistor also flow through the series resistors via a positive and negative voltage regulator, but the resulting voltage fluctuations are not present at the differential voltage amplifier.
Unteranspruch 2:Sub-claim 2:
Einschaltverzögerung, dadurch gekennzeichnet,daß die Versorgungsspannung des Differenzspannungsverstärkers nur langsam ansteigt,weil die Basis der zwei Regeltransistoren nicht nur an der jeweiligen Zenerdiode liegt, sondern auch an den Elektroden eines Kondensators. Dieser lädt sich über zwei Widerstände nur langsam auf.Diese Widerstände begrenzen auch den Strom derSwitch-on delay, characterized in that the supply voltage of the differential voltage amplifier rises only slowly because the base of the two control transistors is not only connected to the respective zener diode, but also to the electrodes of a capacitor. It charges slowly via two resistors, which also limit the current of the
Zenerdioden und den Basisstrom der Regeltransistoren.Die Entladung des Kondensators nach dem Ausschalten kann relativ schnell über die Basis-Colektor-Dioden der Regeltransistoren erfolgen. Zener diodes and the base current of the control transistors. Discharge of the capacitor after switching off can take place relatively quickly via the base colector diodes of the control transistors.
PCT/DE1985/000077 1984-03-14 1985-03-12 Linear amplifier circuit for direct current and alternating current WO1985004294A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19843409330 DE3409330A1 (en) 1984-03-14 1984-03-14 LINEAR DC-AC AMPLIFIER CIRCUIT
DEP3409330.3 1984-03-14

Publications (1)

Publication Number Publication Date
WO1985004294A1 true WO1985004294A1 (en) 1985-09-26

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Application Number Title Priority Date Filing Date
PCT/DE1985/000077 WO1985004294A1 (en) 1984-03-14 1985-03-12 Linear amplifier circuit for direct current and alternating current

Country Status (3)

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EP (1) EP0173724A1 (en)
DE (1) DE3409330A1 (en)
WO (1) WO1985004294A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3602908A1 (en) * 1986-01-31 1987-08-06 Standard Elektrik Lorenz Ag Amplifier circuit for amplifying an alternating voltage

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3818361A (en) * 1971-12-20 1974-06-18 Nippon Kogaku Kk Voltage-power booster for an operational amplifier
US3919655A (en) * 1973-12-26 1975-11-11 Electronics Research Group Inc High power operational amplifier
US3988691A (en) * 1975-04-16 1976-10-26 Kelvin Shih Power amplifier

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3818361A (en) * 1971-12-20 1974-06-18 Nippon Kogaku Kk Voltage-power booster for an operational amplifier
US3919655A (en) * 1973-12-26 1975-11-11 Electronics Research Group Inc High power operational amplifier
US3988691A (en) * 1975-04-16 1976-10-26 Kelvin Shih Power amplifier

Also Published As

Publication number Publication date
EP0173724A1 (en) 1986-03-12
DE3409330A1 (en) 1985-09-26

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