SU403061A1 - COMMUNICATION DEVICE - Google Patents

Description

one

The invention relates to the field of radion electronics, in particular, to semiconductor switches intended for use in automation devices and computer technology in the construction of analog signal switches.

A switching device is known, which contains a key device consisting of a pair of transistors, the collectors and bases of which are combined, an isolated power source, a circuit for connecting an isolated source of power to a key device, and a control circuit made on transistors.

However, the known device has insufficient isolation of control circuits from control circuits, high leakage currents of a private key, high potentials of control voltages, and low speed.

In order to reduce the distortion of the switched signal and reduce leakage currents in the proposed switching device, the connection circuit is made of two transistors, the emitters of which are connected to the buses of the isolated power source, the collector of one of the transistors of the connection circuit is connected via a resistor to the collectors of the transistor key device, and the collector of the other transistor is with - bases of transistors of the key device, base

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The transistors of the connection circuit, between which the resistor is connected, are connected to the collectors of the transistors of the control circuit, the emitters of which are connected to the power buses, and the bases through the resistors connected to the corresponding power buses and collectors of the input transistors of the control circuit, the emitters of the input transistors of the circuit The controls are interconnected, and the bases are connected to the control buses.

A resistor is included to increase the speed between the collectors and the transistor bases of the key device.

The drawing shows a circuit diagram of the proposed device.

The device contains a key device on two transistors 1 and 2, the collectors and bases of which are combined, an isolated power supply source 3, a connection circuit on transistors 4 and 5 of an isolated source 3 to a key device, a correction circuit on transistors 6, 7 and input transistors 8 and 9, as well as resistors 10-16 and control buses 17 and 18.

The emitter of transistor 1 is the input of the analog switching signal and the emitter of transistor 2 is the output.

The circuit is controlled by the voltage supplied to the base of the base-paths 8 and 9. In the case when the thermal on the base of transistor 8 is higher than the potential on the base of transistor 9, these transistors are open and the current flows from the source through resistors 10 and 11, transistors 8 and 9, resistors 12 and 13 to source -EI. At the same time, a potential is formed on resistors 10 and 13, capable of introducing transistors 6 and 7 into saturation mode, and the source voltages are almost completely transmitted to resistor 14. Etn voltage locks transistors 1 and 5, and transistors 1 and 2 are simultaneously locked due to the absence of current flowing through the control collector-base transitions of these transistors.

If the base potential of the transistor 8 is lower than the base potential of the transistor 9, then these transistors are locked. The bases of the transistors 7 and 6 are connected through the resistors 10 and 13 with the power sources t-fi and -EI, respectively, and these transistors are also locked. In this mode, the base transistors

4 and 5 are at a zero potential, connected by a resistor 14. The emitter-base transitions of transistors 4 and 5 begin to operate as diodes shifted in the forward direction along the circuit: source 3 () -interter-base of transistor 4 - resistor 14, base of transistor 5 - -EI current flows, which opens the transistors 4 and 5. The current from the source 3 flows the same way along the circuit: - trapsistor 4 - resistor 16 - collector-base of transistors 1 and 2, transistor

5- -EZ, and transistors 1 and 2 open. Source 3 remains all times isolated from earth. In the open state of the key, the source 3 is isolated from the ground by a large resistance of the closed transistors 7 and b, and in the open state - by the resistance of the locked transitions of the base-emitter of transistors 4 and 5.

Such switching-on of transistors 8 and 9 allows to control the voltage drop across the circuit, regardless of the polarity of the voltage of the power supply sources of the previous circuits, and also makes it not critical to the amplitudes of the control pulses.

Subject invention

Claims (2)

1. A switching device containing a key device consisting of a pair of transistors, the collectors and bases of which are combined, an isolated power source, an isolated source connection circuit power supply to the key device and control circuit, performed on transistors, characterized in that, in order to reduce distortion of the switched signal and reduce leakage currents, the connection circuit is made on two transistors, the emitters of which are connected to the buses of the isolated power supply source, the collector of one of the transistors of the connection circuit connected through a resistor to the collectors of transistors the key device, and the collector of the other transistor - with the bases of the transistors of the key device, the transistor bases of the connection circuit, between which the resistor is connected, are connected to the transistor collectors of the control circuit, the emitters of which are connected to the power supply wires, and the bases are connected to the corresponding power and collector widths through the resistors. The input transistors of the control circuit, the emitters of the input transistors of the control circuit are interconnected, and the bases are connected to the control buses. 2. A switching device according to claim 1, characterized in that, in order to increase speed, a resistor is connected between the collectors and the bases of the transistors of the key device.