SU917352A1 - Electronic analogue signal switching device - Google Patents

Description

() ELECTRONIC ANALOG SIGNAL SWITCH

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The invention relates to electronic engineering, in particular, to electronic switching technology and can be used, for example, in the construction of electronic control and measurement systems.

Known electronic switch analog signals containing operational amplifiers and field-effect transistors as switching elements, the sources of the first and field-effect transistors, the drains of which are connected respectively to the inverting input and output of the first operational amplifier, are connected to the input bus of the device, the output of the first operational amplifier, covered by a positive reverse connected to the inverting input of the second operational amplifier covered by negative feedback, non-inverting The second input of the second operational amplifier is connected to the output bus of the device.

And it is connected to the common point of the power sources of the op amps 1 T.

The disadvantages of this device include the complexity and small range of switched signals.

The closest in technical essence and circuit implementation to the proposed is an electronic switchboard of analog signals, containing a field effect transistor, the source of which is connected to the input bus of the device and a voltage follower, the input of which is also connected to the input bus of device f2.

The disadvantages of the known device should include a small range of switched signals.

The purpose of the invention is to expand the range of switched signals.

This goal is achieved by the fact that the electronic switch of the analog signals, containing the field transistor whose source is connected to the input bus of the device and the voltage repeater, whose input is also connected to the input bus of the device, introduces a controlled voltage source and an additional voltage follower The output of the power sources of the additional voltage follower, the input and output of which are connected respectively to the source and drain of the field-effect transistor, is connected to the output bus of the device controlling A controlled voltage source, the first and second buses of which are connected respectively to the output of the voltage follower and the gate of the field-effect transistor, is connected to the control bus of the device.

 The drawing shows a schematic diagram j illustrating an example of a specific embodiment of the device.

The electronic switchboard of analog signals contains a field-effect transistor 1, the source of which is connected to the input bus 2 of the device, a voltage follower 3, a controllable voltage source k, busses 5 and 6 of which are connected to the output of the voltage follower 3 and the gate The input of which is connected to the control bus 7, an additional repeater 8 voltage, the common bus of the sources 9 of which power supply is connected to the output bus 11 ..

Electronic switch analog signals works as follows.

With a corresponding value of the control signal supplied to the bus 7 between the buses 5 and 6 of the power supply source k, a zero voltage is established. In this case, the voltage of the field-effect transistor 1 is equal to zero, the transistor 1 is unlocked and the switched signal through the transistor 1 and the small output resistance of the additional voltage follower 8 is fed to the output bus 11 of the device.

If under the action of a control signal between the buses 5 and 6 of the controlled voltage source such a voltage is established that the U of the transistor 1 becomes greater than the cut-off voltage of the ir-this transistor, then the transistor 1 is locked

and the switched signal is not supplied to the output bus 11 of the device.

Thus, the positive effect of the proposed device is due to the introduction of a controlled source of voltage and an additional repeater of voltage. In the locked state of the switch, at any values of the switched circuit

the voltage Uc-i and the voltage between the drain and the gate of the IRE of the field-effect transistor 1 are kept constant and equal to the voltage between the buses of the source 4 of the adjustable

tension Therefore, the amplitude of the switched voltage is not determined by the maximum allowable voltage between the electrodes of the field-effect transistor, which causes

expansion of the range of switched signals.

Claims (2)

1. USSR author's certificate N725231, cl. H 03 K 17/60, 01.16.76 .. 2.Balakai V.G. and others. Integrated circuits of the ADC and DAC. M., Energie, 1978, p. U6, Fig. 3-6. V Well AND