SU425304A1 - DEVICE FOR OBTAINING NEGATIVE RESISTANCES - Google Patents

Description

one

The invention relates to a pulse technique and can be used to construct circuits of various relaxation generators, time relays, pulse-width modulators, triggers, threshold devices, etc.

Devices for obtaining negative resistances are known, which contain a gatip field-effect transistor whose drain through the first resistor is connected to the positive pole of the bias voltage source and a p-p-type bipolar transistor whose collector is connected to the positive pole of the source through the second resistor supply voltage, and the emitter is connected to a common output source.

However, the range of operating voltages in known devices is limited.

The aim of the invention is to expand the range of operating voltages.

For this, the base of the bipolar transistor is connected to the source of the field-effect transistor, the gate of which is connected to the common connection point of the second resistor and collector of the bipolar transistor.

The drawing shows a circuit diagram of the device.

A device for obtaining negative resistances contains a field effect transistor

1 with a diffusion gate n-type, bipolar pn-and-transistor 2, the collector of which is connected to the gate of the field-effect transistor 1, and the emitter - to the common output 3 of sources 4 and 5 of the bias voltage and supply voltage, respectively, resistor 6 bias connected by one output to the drain of the field-effect transistor 1 and the other to the positive pole of the source 4 of the bias voltage, load resistor 7 connected by one output to the common collector point of bipolar transistor 2 and the gate of the field-effect transistor 1, and the other output with positive a pole voltage source 5

power, input terminal 8, at the input of which a 5-type voltage-current characteristic, output terminal 9, at the output of which the L-type voltage-current characteristic. The device works as follows.

If, in the initial state, the voltage on the collector of the bipolar transistor 2 (output terminal 9) exceeds the voltage on the drain of the field-effect transistor 1 (input terminal 8) by the value of the overlap voltage

the drain-source channel, the bipolar transistor 2 is in the closed state. When increasing the input voltage (input terminal 8) to a value slightly higher than the output voltage (output terminal 9), the channel of the field-effect transistor 1 drains

the source opens, a current flows to the base of bipolar transistor 2, as a result of which the voltage on bipolar transistor 2 on collector and on the gate of field-effect transistor 1 drops, which leads to an even greater opening of the channel.

Thus, the process of transition of the device from the closed to the open state is of a regenerative nature. At the input (input terminal 8), the voltage-current dependence has a falling portion (5-type negative resistance).

If, in the open state of the device, the supply voltage is increased, then the voltage on the collector of bipolar transistor 2 and on the gate of field-effect transistor 1 will increase, the drain-source channel will close, which will further decrease the input and output current, i.e. an increase in the output voltage (output terminal 9).

The process of moving the device from an open to a closed state is also of a regenerative nature. At the output (output terminal 9), the volt-ampere characteristic has a falling portion of the Y-type.

Since the overlap voltage of the field-effect transistor 1 is

volts or volts, and the gate-source breakdown voltage is tens of volts, the voltage range at which the input and output impedances are negative is in the range from units of volts or volts to tens of volts.

Subject invention

A device for obtaining negative resistors, comprising a field-effect transistor with a diffusion gate of "-type, whose drain through the first resistor is connected to the positive pole of the bias voltage source, and a Bipolar pn-type transistor, whose collector through the second resistor is connected to the positive the source of the supply voltage, and the emitter is connected to a common output of the sources, characterized in that, in order to expand the range of operating voltages, the base of the bipolar transistor is connected to the source of the field voltage ranzistora whose gate is connected to the common junction of the second resistor and the collector of the bipolar transistor.