Push-pull operational amplifier

 

(57) Abstract:

The invention relates to electronic devices, in particular to amplifiers, and can be used to build integrated circuits. Push-pull operational amplifier with higher gain contains main unit amplification performed on two parallel connected input differential pairs formed by transistors of the first and second type conductivity, respectively. Load each differential pair is bunk reflector current corresponding conductivity type and the transistors of the lower tier of each reflector current allow additional gain due to the different slope of the amplification transistors T4 and T12 in static and dynamic modes, respectively. Put two managed source of rechargen1and In2to set the mode of reduced power consumption of the transistors T4 and T12 in static mode, and consistent with the input control signal their dynamic characteristics AC current through the diodes D3 and D11, and two accelerating capacitors Cy1and CU2excluding amplification cascade transistors T4 and T 12 in onlinecasi result: increase gain without narrowing the frequency bandwidth, increasing the slew rate of the output signal while reducing the power consumption of the main amplifier unit. 2 Il.

This invention relates to electronic devices, in particular to amplifiers, and can be used to build integrated circuits.

Known technical solution [D. Connelly. Analog integrated circuits, translation from English. M.: Mir, 1977, S. 118, Fig. 333] contains the input differential pair transistor T5 and T6, the reflector current ON-1 transistors T1 and T2, the reflector current FROM 2 transistors T3 and T4 and the source of constant current.

The disadvantage is its low coefficient of efforts.

The closest technical solution is push-pull operational amplifier to the main amplifier unit (Fig.1) [Dr. Go directly Lidgey, Analogue Action, 1 GHz gain-bandwidth operational amplifiers, Electronics &wireless world, Sep, 1989, T9, OY EL2038 Elarttec], containing the first input differential pair transistors T5, T6 of the first conductivity type with interconnected emitters, the base of which is connected to the input terminals (+) and (-) respectively, while the collector of transistor T5 is connected to the bus of the source of positive supply En+and the collector of transistor T6 is connected to the ora T12 and the input buffer, the base of transistor T4 is connected to the base of transistor KZT18, and with the cathode of the diode D3 and with one end of the constant current source IT, and the anode of diode D3 is connected to the cathode of the diode D1, the anode of which is connected through a resistor R1 to a source of positive voltage En+and with the bases of the transistors T17 and KZT18, the emitters of which through the resistors R5 and R2 respectively connected to the source of positive voltage En+while the collector of transistor T17 is connected to the emitter of the transistor KZT18, the collector of which is connected to the emitters of transistors T7, T8; the second input differential pair transistors T7, T8 of the second conductivity type with interconnected emitters, the base of which is connected to the bases of transistors T5, T6 and the input terminals (+) and (-) respectively, while the collector of transistor T7 is connected to the bus of the source of negative supply En-and the collector of transistor T8 is connected to the collector of the transistor T10 and the emitter of the transistor T12 and to the input buffer of the output stage and the base of transistor T12 is connected to the base of transistor kzt19, and with the anode of the diode D11 and the second end of the constant current source IT, and the cathode of diode D11 is connected to the anode of the diode D9 and the cathode of the diode D9 through resistor R3 to the collector of transistor T20 is connected to the emitter of the transistor kzt19, collector connected to the emitters of transistors T5 and T6.

The disadvantage of the prototype is limited (low) gain voltage due to the use of one (push-pull) amplifier.

The objective of the invention is the achievement of the technical result consists in increasing the gain without narrowing the frequency bandwidth, higher slew rate of the output signal while reducing the power consumption of the main amplifying unit by introducing two controlled sources of support for the In1and In2performed on the transistors T17, KZT18, and the resistors R5 and R6, respectively, which provide a lower power consumption of the transistors T4 and T12 DC and consistent with the input control signal of the collector currents of the transistors T4 and T12 in the dynamic mode using diodes D3 and D11, respectively, and also accelerating the introduction of two capacitors Cy1and CU2excluding amplification cascade transistors T4 and T12 in the field of high frequencies, which reduces the capacity of the primary correction capacitor Ccor.

The task dostepu input differential pair transistors T5 and T6 of the first conductivity type, base of which is connected to the input terminals (+) and (-), and their emitters are connected, and one end of the constant current source IST-1, the second end of which is connected to a source of negative voltage En-the reflector current ON-1 on the transistor T2 and the diode D1 and the reflector current FROM a-2 to the transistor T4 and the diode D3, the anode of the diode D1 and the emitter of the transistor T2 through the resistors R1 and R2 respectively connected to the bus of the source of positive voltage En+and the base of transistor T2 is connected to the cathode of the diode D1 and the anode of the diode D3, the collector of transistor T2 is connected to the emitter of the transistor T4 and the collector of transistor T6 and the collector of transistor T4 is connected to the input of buffer stage and to the collector of the transistor T12, the second input differential pair transistors T7 and T8 of the second conductivity type, the base of which are connected respectively to the bases of transistors T5 and T6, and their emitters connected with each other and with one end of the constant current source ICT-2, the second end of which is connected to a source of positive voltage En+the reflector current ON-3 transistor T10 and the diode D9 and the reflector current ON-4 on the transistor T12 and the diode D11, and the cathode of the diode D9 and the emitter is implemented is - and the base of transistor T10 is connected to the anode of the diode D9 and the cathode of the diode D11, and the collector of transistor T10 is connected to the emitter of the transistor T12 and the collector of the transistor T8, the introduction of two controlled current sources feeding In1and In2the first source of recharge In1formed by the transistor T17 and the resistor R5 and the base of transistor T17 is connected to the cathode of the diode D1 and the emitter of the transistor T17 is connected through resistor R5 to a source of positive voltage En+the collector of transistor T17 is connected to the emitter of the transistor T4 and with one end of the accelerating capacitor Cy1the second end of which is connected to the collector of transistor T4, the base of which is connected to the collector of transistor T5 and to the cathode of the diode D3, the second source of recharge In2formed by transistors KZT18, and the resistor R6 and the base of the transistor KZT18, is connected to the anode of the diode D9 and the emitter of the transistor KZT18, is connected through resistor R6 to the negative source voltage En-the collector of transistor KZT18, is connected to the emitter of transistor T12 and with one end of the accelerating capacitor CU2the second end of which is connected to the collector of the transistor T12, the base of which is connected to the collector of transistor T7 and a is the controlled current sources feeding In1and In2transistors T17 and KZT18, and the resistors R5 and R6, respectively, two accelerating capacitorsN1and CU2and new relationships, namely the connection base of the transistor T4 to the cathode of the diode D3 and the collector of transistor T5 and the connection base of the transistor T12 to the anode of the diode D11 and the collector of the transistor T7, which enables 4-5 times to increase the gain of the voltage, reduce by 30% the power consumption of the main amplifying unit while maintaining the bandwidth and increase the slew rate of the output signal.

The effect of increasing the gain is achieved by the fact that the transistor T4(T12) operates in an active mode with reduced power consumption, defined by the current makeup In1(In2). Current recharge In1(In2is chosen to be smaller than the current of the constant current source IT (TFI2), so in the static mode, the steepness of the transistor T4(T12) is 4-5 times smaller than the slope of the input transistor T5(T7).

In dynamic mode, when applying to the input of the transistor T5 of the positive half wave sinusoidal signal transistor T4 has the same slope as that of the transistor T5 and the diode D3, and since the transistor T2 with the diode D1 and the transistor T4 with the diode D3 obrazujetsia sinusoidal input signal UI. completely passed by the transistor T4 to the input of the buffer stage. The gain of the voltage is determined using the following expression:

TOU=KThe Un,

where n=S5/S41/2IEast/In1>>(4-5);

S5and S4the steepness of the transistors T5 and T4 in the static mode.

Thus, the patent research confirmed the novelty of the invention, and also showed that in the literature there are no data that indicate the effect of the distinguishing signs on the achievement of the technical result.

The device operates as follows. In the statistical mode (input signal UI= 0), the source current of the constant current IST is divided equally between the emitters of the transistors T5 and T6. The collector current of the transistor T5 flows through the diodes D3 and D1 and resistor R1 to a source of positive voltage En+and the collector current of the transistor T6 is fully flows to the collector of the transistor T2 and the resistor R2 to a source of negative voltage En-. The collector current of the transistor T2 and the current of the diode D1 are the same, as they form the upper reflector of the current ON-1. The collector current of the transistor T4 is determined by the thickness of IT. However, the magnitude of the voltage emitter-base of transistor T4 DC is the same as that of the diode D3, so the transistor T4 DC working in active mode with reduced power consumption.

The steepness of the transistor T4 is much smaller than the slope of the input transistor T5. If the current feed In1transistor T4 is equal to the collector current of the transistor T5, and its base would be connected to a DC voltage source, as is the case in the prototype, the gain of the stage is determined by the following ratio:

< / BR>
where RI,B- input impedance buffer cascade;

rk4and rk12- resistance collector transitions of transistors T4 and T12;

re- differential resistance of the emitter junction T5;

S5=1/rethe steepness of the transistor T5.

Because the steepness of the transistor T4 is less than the slope of the transistor T5, the gain is determined by the ratio:

TOU-(S5RI,B)1/2(S5/S4)................,

where S4the steepness of the transistor T4;

S5/S4810.

In the dynamic mode (for example, when applying to the input of the transistor T5 is positive while ON-1 (diode D1 and the transistor T2) is fully transmitted to the transistor T2, and since the diode D3 and the transistor T4 AC form reflector current ON-2, then increment collector current Ik2= Ik5fully enters the emitter of the transistor T4 and is in the form of a voltage on the input impedance of the buffer. However, at the emitter of transistor T4 is secreted voltage that is greater than the input 1/2(S5/S4) times, at the same time, the transistor T4 in conjunction with the diode D3 form a "cascade" mode current control, so narrow bandwidth of frequencies does not occur. Moreover, the introduction of accelerating capacitor Cy1allows high frequencies to exclude part of the gain obtained with the aid of the transistor T4. This makes it possible to reduce 1.5 times the frequency-correcting capacity WITHcorand thereby to maintain the frequency bandwidth for small signal and to increase the slew rate of the output signal to a large signal. When submitting to the bases of transistors T5 and T7 of the negative half works the lower part of the push-pull amplifier. Thus, the upper part of the amplifier amplifies the positive half-wave, and the bottom is negative.

Push-pull operational amplifier containing the first input differential is (-), and their emitters connected with each other and with one end of the constant current source IST-1, the second end of which is connected to a source of negative voltage En-the reflector current ON-1 on the transistor T2 and the diode D1 and the reflector current FROM a-2 to the transistor T4 and the diode D3, the anode of the diode D1 and the emitter of the transistor T2 through the resistors R1 and R2 respectively connected to the bus of the source of positive voltage En+and the base of transistor T2 is connected to the cathode of the diode D1 and the anode of the diode D3, the collector of transistor T2 is connected to the emitter of the transistor T4 and the collector of transistor T6 and the collector of transistor T4 is connected to the input of buffer stage and to the collector of the transistor T12, the second input differential pair transistors T7 and T8 of the second conductivity type, the base of which are connected respectively to the bases of transistors T5 and T6, and their emitters connected with each other and with one end of the constant current source ICT-2, the second end of which is connected to a source of positive voltage En+the reflector current ON-3 transistor T10 and the diode D9 and the reflector current ON-4 on the transistor T12 and the diode D11, and the cathode of the diode D9 and the emitter of the transistor T10 through resistors R3 and R4, respectively, soy is an ode to D9 and with the cathode of the diode D11, and the collector of transistor T10 is connected to the emitter of the transistor T12 and the collector of transistor T8, characterized in that it introduced two controlled current sources feeding In1and In2the first current source feeding In1formed by the transistor T17 and the resistor R5 and the base of transistor T17 is connected to the cathode of the diode D1 and the emitter of the transistor T17 is connected through resistor R5 to a source of positive voltage En+the collector of transistor T17 is connected to the emitter of the transistor T4 and with one end of the accelerating capacitor Cy1the second end of which is connected to the collector of transistor T4, the base of which is connected to the collector of transistor T5 and to the cathode of the diode D3, the second source of recharge In2formed by transistors KZT18, and the resistor R6 and the base of the transistor KZT18, is connected to the anode of the diode D9 and the emitter of the transistor KZT18, is connected through resistor R6 to the negative source voltage En-the collector of transistor KZT18, is connected to the emitter of transistor T12 and with one end of the accelerating capacitor CU2the second end of which is connected to the collector of the transistor T12, the base of which is connected to the collector of transistor T7 and to the anode of diode D11.

 

Same patents:

The invention relates to electronics, and more specifically to amplifiers audio-frequency

The invention relates to electrical engineering and can be used in electronic devices for various purposes, in particular, in the amplifying devices, switching devices, oscillators

The invention relates to electrical engineering and can be used in the integral analog devices

The invention relates to the field of microelectronics and can be used to amplify signals

The invention relates to an analog technique and can be used in ultra-wideband communication devices, automation, measurement and computing

Amplifier // 2065662
The invention relates to electronic devices and can be used to amplify signals with high dynamic accuracy

The invention relates to the measurement electronics, and more specifically to precision measuring operational amplifiers, and can be used, for example, in medical diagnostic equipment in the field of Electrocardiology, electroencephalography, electromyography, etc

The invention relates to measuring electronics, in particular for precision measurement of operational amplifiers, and can be used, for example, in medical diagnostic equipment in the field of electrocardiography, electroencephalography, electromyography, etc

The invention relates to the measurement electronics, and more specifically to precision measuring operational amplifiers, and can be used, for example, in medical diagnostic equipment in the field of cardiology, encephalography, biografii, etc

The invention relates to the field of amplifier and generator technology and can be used in wideband transmission paths of the audio range of frequencies for broadcasting and communication zvukoprovodnost

The invention relates to electronics, instrumentation, automation, in particular for low-noise precision amplifier current in the integrated design, and can be used in the preliminary stages of devices linear current amplification

The invention relates to electronics, instrumentation, automation and can be used in the preliminary stages of devices linear current amplification

The invention relates to electrical engineering and can be used in high-frequency broadband push-pull power amplifiers included in a transmitting devices

The invention relates to a pulse technique, and more particularly to devices for converting pulses with reduced steepness of the front, and can be used to reduce distortion of the pulses while maintaining high conversion efficiency voltage current, as well as to reduce the DC component of the current output device

The invention relates to electronics and can be used as a powerful output stage in the composition of the low frequency amplifier, DC, video amplifier, various transducers, measurement equipment, output or grooms cascades transmitting devices in the range up to 10 MHz

The invention relates to electronics, and more specifically to amplifiers audio-frequency

The invention relates to electrical engineering and can be used in the Converter equipment

The invention relates to analog computing, and may find application in discrete-analog signal converters, the readers of the output signals of integrated circuits with charging connection, and broadband devices power amplification

FIELD: radio engineering; high-linearity voltage-current converters designed for active operation in wide range.

SUBSTANCE: proposed differential amplifier is designed for operation in miscellaneous analog integrated circuits (for instance, in high-speed operational amplifiers, analog signal multipliers, and the like), within a wide range of 50 to 60 mV up to units of Volts in nonlinear modes limited by final speed of differential amplifier. Speed of the latter rises due to dynamic growth of recharge currents through correcting capacitor at maximal rate of output voltage rise comparable with its speed in linear modes. Differential amplifier has input transistors 1, 3, reference current supplies 2, 4, auxiliary resistor 5 inserted between emitters of transistors 1, 3, and load circuit connected to collectors of transistors 1, 3. Newly introduced are transistors 8, 9 of different structure whose emitters are connected through additional resistors 10, 11 to emitters of transistors 3 and 1, respectively. Bases of transistors 8, 9 are connected to those of transistors 3, 1, respectively.

EFFECT: enlarged active operating range of differential amplifier.

4 cl, 5 dwg

Up!