RU2078397C1 - Voltage repeater - Google Patents

Abstract

FIELD: electronic circuits. SUBSTANCE: device has bipolar transistors 1, 2, 3 and 6 and introduced different amplifiers 4 and 5. EFFECT: increased speed when capacitance load is connected. 1 dwg

Description

 The invention relates to electrical engineering and can be used in electronic circuits for various purposes.

 The closest in technical essence is the voltage follower containing the first transistor, the base of which is the input of the voltage follower, the emitter is connected to the collector of the first transistor and the base of the second transistor, the collector of which is connected to the first power bus and the emitter of the first transistor, the emitter of the second transistor a voltage follower and is connected to a collector of a second current-carrying transistor, the emitter of which is connected to a second power bus.

 The disadvantage of the prototype is the relatively low speed when working on capacitive load.

 The purpose of the invention is to increase the speed of the device when operating at capacitive load.

 This goal is achieved by the fact that in the voltage follower containing the first transistor, the base of which is the input of the voltage follower, the emitter is connected to the collector of the first transistor and the base of the second transistor, the collector of which is in turn connected to the first power bus and the emitter of the first transistor, the emitter the second transistor is the output of the voltage follower and is connected to the collector of the second current-supply transistor, the emitter of which is connected to the second power bus The first and second differential amplifiers are introduced, the inverting inputs of which are connected to the base of the first transistor, non-inverting to the emitter of the second transistor, and the outputs to the base of the first and second current-carrying transistors, respectively.

 The drawing shows a diagram of the proposed device.

 The device contains bipolar transistors 1, 2, 3, and 6, differential amplifiers 4 and 5, the base of transistor 1 being the input of a voltage follower, the emitter connected to the collector of the first current-substituted transistor 6, and the base of transistor 2, the collector of which is connected to the first power bus and emitter of the first of the transistor 6, the emitter of the transistor 2 is the output of the voltage follower and is connected to the collector of the second transistor 3, the emitter of which is connected to the second power bus, the inverting inputs of the differential Ferencial amplifiers 4 and 5 are connected to the base of transistor 1, non-inverting inputs to the emitter of transistor 2, and outputs to the bases of current-carrying transistors 6 and 3, respectively.

 The voltage follower operates as follows.

 When a positive difference appears at the input of the circuit, for example, transistor 1 closes, the collector current of transistor 6 flows to the base of transistor 2, amplifies and charges the load capacities, while the output voltage lags behind the input, so the voltage at the inverting input of the differential amplifier (DU) 4 becomes more than on a non-inverting one, as a result of which the output current of the remote control 4 appears, which enters the base of the transistor 6, which amplifies it and transfers it to the base of the transistor 2, which leads to an increase in the charge current of the load capacitance .

The charge current of the load capacitance is
I $\genfrac{}{}{0ex}{}{\text{(+)}}{\text{3}}$ = Δu • S ₄ β ₆ • β ₂ ,
where Δu is the input-output voltage difference;
S _{4 the} steepness of the transmission of remote control 4;
β _i current transfer coefficient of the i-th transistor in the circuit with OE.

 When a negative pulse appears, transistor 1 opens, taking the current of transistor 6 and from the base circuit of transistor 2, while the output voltage lags behind the input voltage, the voltage at the non-inverting input of the ДУ5 becomes greater than at the inverting one. As a result, the transistor 3 opens, which provides a quick recharge of the load capacitance.

The value of the charge current with a negative half-wave
I $\genfrac{}{}{0ex}{}{\text{(-)}}{\text{3}}$ = Δu • S ₅ β ₃ .

The prototype has a maximum charge current with a positive half-wave
I $\genfrac{}{}{0ex}{}{\text{(+)}}{\text{3}}$ = I _o • β ₂ ,
where I _{0 the} current of the first transistor,
and with a negative half-wave
I $\genfrac{}{}{0ex}{}{\text{(-)}}{\text{3}}$ = I _o • K ₃ α ₁ ,
where α ₁ current transfer coefficient in the circuit with OB;
K ₃ the current transfer coefficient of the transistor 3.

 It is obvious that the determined circuit provides a significantly larger recharge current of the load capacitance, and, as a result, higher speed.

 Literature: US Patent N 4103248, H 03 F 3/18, published. 07/25/78, Fig.4.

Claims (1)

 The voltage follower containing the first transistor, the base of which is the input of the voltage follower, the emitter is connected to the collector of the first current transistor and the base of the second transistor, the collector of which is connected to the first power line and the emitter of the first current transistor, the emitter of the second transistor is the output of the voltage follower and connected to the collector a second pick-up transistor, the emitter of which is connected to a second power bus, characterized in that the first and second differential These are amplifiers whose inverting inputs are connected to the base of the first transistor, non-inverting inputs to the emitter of the second transistor, and the outputs to the bases of the first and second current-carrying transistors, respectively.