SU985933A1

SU985933A1 - Differential amplifier

Info

Publication number: SU985933A1
Application number: SU802906083A
Authority: SU
Inventors: Григорий Степанович Остапенко; Александр Григорьевич Остапенко; Анатолий Павлович Удовик
Original assignee: Предприятие П/Я Х-5446; Воронежский Политехнический Институт
Priority date: 1980-04-04
Filing date: 1980-04-04
Publication date: 1982-12-30

Description

154) ДИФФЕРЕНЦИАЛЬНЫЙ УСИЛИТЕЛЬ154) DIFFERENTIAL AMPLIFIER

Изобретение относитс к радиоэлектронике и может использоватьс во входных каскадах усилительных устройств автоматики, радиоэлектроники и измерительной техники.The invention relates to radio electronics and can be used in the input stages of amplifying devices of automation, radio electronics and measuring equipment.

Известен дифференциальный усилитель , содержащий в каждом плече первый и второй транзисторы типа проводимости, третий и четвертый транзисторы и первый резистор, один вывод которого соединен с шиной источника питани , база первого транзистора п-р-п типа проводимости вл етс одним из входов дифференциального усилител , эмиттер соединен с базой второго транзистора п-р-п типа проводимости, эмиттер которого, в свою очередь, подключен к стабилизатору тока, соединенному с общей шиной, а коллектор - к одному из выходов дифференциального усилител 1.A differential amplifier is known, containing in each arm the first and second transistors of the conduction type, the third and fourth transistors and the first resistor, one output of which is connected to the power supply bus, the base of the first transistor of the pnp conductivity type is one of the inputs of the differential amplifier, The emitter is connected to the base of the second transistor of the pn type of conductivity, the emitter of which, in turn, is connected to a current regulator connected to a common bus, and the collector is connected to one of the outputs of the differential amplifier. Itel 1.

Недостаток известного усилител низк ,а температурна стабильность. The disadvantage of the known amplifier is low, and the temperature stability.

Цель изобретени - повышение температурной стабильности.The purpose of the invention is to increase the temperature stability.

Дл достижени поставленной цели в ка щое плечо дифференциального усилител введены резистивный делитель, включенный между шиной источникаTo achieve this goal, a resistive divider connected between the source bus is inserted into each shoulder of the differential amplifier.

питани и общей шиной, и второй резистор , при этом коллектор второго транзистора п-р-п -типа проводимости соединен с коллектором третьего транзистора, эмиттер которого подключен к шине источника питани , а база - к точке соединени одного вывода второго резистора и эмиттера четвертого транзистора, база которо10 го соединена с резистивным делителем, а коллектор - с базой первого трАнзистора п-р-п типа проводимости, коллектор которого подключен к точке соединени других выводов первого и power and common bus, and the second resistor, while the collector of the second transistor n-pp-conductivity type is connected to the collector of the third transistor, the emitter of which is connected to the power supply bus and the base to the connection point of one output of the second resistor and emitter of the fourth transistor The base of which is connected to a resistive divider, and the collector is connected to the base of the first transistor of the pnp conductivity type, the collector of which is connected to the point of connection of the other terminals of the first and

15 второго резисторов, при этом третий и четвертый транзисторы выполнены р-п-р -типа проводимости. .15 second resistors, while the third and fourth transistors are made of pnp-type conductivity. .

На чертеже приведена электрическа принципиальна схема предлага20 емого дифференциального усилител .The drawing shows an electrical schematic diagram of the proposed 20 differential amplifier.

Дифференциальный усилитель в каждом плече содержит первый и второй ; транзисторы 1 и 2 п-р-п-типа проводи25 мости, третий и четвертый транзисторы 3 и 4, первый и второй резисторы 5 и 6, резистивный делитель 7, а так же стабилизатор 8 тока.The differential amplifier in each arm contains the first and second; transistors 1 and 2 are pn-type conductors, third and fourth transistors 3 and 4, first and second resistors 5 and 6, resistive divider 7, as well as current regulator 8.

Claims

Differential amplifier 30 melts as follows. When supplying a differential voltage source between the inputs of a signal source that is not connected to a common bus, the voltage on the base of one of the first transistors 1 increases, then on the base of the first transistor 1 symmetrical to it, it should decrease by the same amount. Input ex. The amplification, amplified by the first transistor 1, through the second resistor b is fed to the emitter of the fourth transistor 4, forming an active negative current feedback, which stabilizes the high input resistance of the differential amplifier. At the same time, the signal amplified by the first transistor -1 is fed to the base of the third transistor 3, the dynamic load of which is the second transistor 2; The signal from the emitter of the first transistor 1 is fed to the base of the second transistor 2, whose collector load is the third transistor 3. The operation of the other arm of the differential amplifier occurs in a similar way. Thus, the dynamic load stage, which has a high gain factor, zyu, which stabilizes the parameters of the differential amplifier. The construction of the input stages in such a way that the first transistors 1 operate with the initial base currents allows the use of a differential amplifier in conjunction with the input signal sources not connected to the common bus. In this case, the base currents of the first transistors 1 are stabilized by active negative current feedback, which both ensures a high input resistance and its stabilization in a wide range of temperature and supply voltage. . Balancing the differential amplifier over the chain base of the fourth transistor 4 makes it possible to eliminate its effect on the input parameters of the differential amplifier. The proposed differential amplifier can be widely used by measuring equipment and automation devices that use sensors that do not have a constant component signal, for example , capacitive, piezoelectric, ferrite magnetic, etc. Invention Differential amplifier, containing in each arm the first and second transistors of pnp conductivity type, third and fourth transistors and the first resistor, one KOTOjxsro pin connected to the power supply bus, the base of the first transistor nnpn conductivity type is one of the inputs of the differential amplifier inputs, the emitter is connected to the base of the second transistor of the pn type of conductivity, the emitter of which in turn is connected to the current stabilizer connected to the common bus, and the collector to one of the outputs A social amplifier, characterized in that, in order to increase temperature stability, a resistive divider connected between the power supply bus and the common bus and the second resistor are inserted into each shoulder of the differential amplifier, while the collector of the second transistor is of pnp-type conductivity connected to the collector of the third transistor, the emitter of which is connected to the power supply bus, and the base to the connection point of one output of the second resistor and emitter of the fourth transistor, the base of which is connected to the resistor elem, and the collector to the base of the first transistor is an n-p-n conduction type, whose collector; connected to the connection point of the other terminals of the first and second resistors, while the third and fourth transistors are made with pnp-type conductivity. Sources of information taken into account in the examination 1. USSR author's certificate 308483, cl. H 03 F 3 / 2b, 01.07.71 (prototype).