SU603096A1 - Push-pull amplifier - Google Patents

Description

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FIELD OF THE INVENTION The invention relates to radio engineering and can be used in automatic control devices, in particular in the sln systems.

Known amplifier with non-primary, connection, containing preliminary and output cascades, the shoulders of each of which are made on complementary transistors connected according to the scheme with a common emitter Jl}

However, the known two-phase amplifier j has a relatively small dynamic range.,

The purpose of the invention is the extension of the aiamic range of the amplifier.

To do this, in the proposed push-pull | g amplifier with direct connections, an additional transistor of the opposite conduction type, 20, the base of which is connected to the base of the additional transistor of the opposite shoulder, is introduced into the shoulder of each pr. the current generator is made on resistors, the connection point of which is connected to the input-25 source

or on complementary transistors, the emitters of which are connected via a resistor, and the bases to the collectors of the transistors of the respective arms of the output stage.

FIG. Figure 1 shows the circuit diagram of the proposed push-pull amplifier; in fig. 2 is the same with the current generator made on the resistors in FIG. 3 - the same, with a current generator, made on transientors.

Claims (2)

A push-pull amplifier with direct connections contains preliminary and output stages 1, 2, the shoulders of each of which are made on complementary transistors 3, 4 and 5, 6, in each arm of the preliminary stage 1 connected in series with transistors 3,4 additional transistors 7, 8 The base of one of them is connected to the base of the other through a current generator 9, which is filled on resistors 10, 11, the connection point of which is connected to the input source 12, or complementary transistors 13, 14, the emitters of the latter are connected through Reistor 15, and the base - with the collectors of the transistors 5, 6 of the corresponding shoulders of the output stage 2. The amplifier works as follows. With a positive voltage at the input of the amplifier (on the bases of complementary transistors 3, 4), the complementary transistors 5 are open, the complementary 4, 6 are locked. With a saturated transistor 5, the collector-emitter voltage of transistor 6 is almost twice the supply voltage. The base current of the additional transistors 7, 8 is equal to the current of the generator 9. Since the emitter-collector voltage of the additional transistor 7 is equal to the base-amitter voltage of the open transistor 5, the additional transistor 7 is in the active region, through it a part of the collector current of transistor 3, The reverse current of the collector junction 1 of transistors 4, 6 flows through the collector circuit of transistor 8, which, with a sufficient amount of current from generator 9, is in the saturation region. The base-emitter voltage of transistor 6, which is equal to the collector-emitter voltage of the natiate additional transistor 8, is close to zero, therefore the collector-emitter voltage of the transistor 6 is close to the collector-emitter voltage of the shorted base. When the sign of the input voltage changes, the transistors 4, 6 are open. Part of the current of the collector of the transistor 4, is equal to the current 1. collector of the additional transistor 8, flows through this additional transistor to / Р-е, where bg is the coefficient of us „current power of the additional transistor 8; 1g generator 9. transistors 4, 6 Since the current 1 is much less than the rated currents of the collector of these transistors 4, 6, it is necessary for the additional transistor 8 to go to the saturation region when. transistors 4, 6 3anegTbi, the current value of 1p can be chosen small. Consequently, the magnitude of current 1 is small. When the olletor transistor 4 is greater than Kg, all increments of the base current of the transistor are equal to the collector current increment of the transistor 4, therefore, along with the increase in the supply voltage, which should be less than the breakdown voltage of the emitter, the gain is kept high. from the circuit with shunt resitel. Claim 1. Direct-coupled push-pull amplifier containing preliminary and output cascades, each shouldered on complementary transistors connected in a circuit with a common mitter, characterized in that, in order to expand the dynamic range, into each arm of the preliminary cascade in series with direct current with a shoulder transistor, an additional transistor of the opposite type of conductivity is introduced, the base of which is connected to the base of the additional transistor oppositely of the shoulder through the alternator. 2. Amplifier according to claim 1, characterized in that the current generator is made on resistors, the junction point of which is connected to the input source. 3 „Amplifier according to claim 1, of tl and h a yush and s. the current generator is made on complementary transistors, the emitters of which are connected via a resistor, and the bases are connected to the collectors of transistors of the respective arms of the output stage. Sources of information taken into account in the examination: 1. Shilo V. L. Linear integrated circuits in electronic equipment, Moscow, Soviet radio, 1974, p. 112, fig. 4.7g f-p l rR P I U ABOUT -o + 0ut