RU2469474C1 - Mis transistor power key - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: MIS transistor power key is proposed, comprising a transformer, the end of the secondary winding of which is connected directly with the source of the MIS transistor, two diodes and a resistor, an anode of the first diode and a cathode of the second diode are connected to the start of the secondary winding of the transformer, the cathode of the first diode - directly, and the anode of the second diode via the resistor are connected to the gate of the MIS transistor. At the same time two capacitors are introduced, the first one is connected between the gate and the source of the MIS transistor, the second one - between the anode of the second diode and the source of the MIS transistor.

EFFECT: improving power key operation reliability.

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Description

The invention relates to a pulse technique and can be applied in various switching devices, especially in switching devices of spacecraft, where there is exposure to heavy charged particles, and also where fast switching of keys with steep voltage and current fronts is required, leading to interference, since it’s better not to create interference than to deal with them later.

A power switch for an MOS transistor is known, which contains a transformer, a resistor, diodes and two transistors, emitters and bases of two complementary transistors are connected directly, emitters of transistors are connected to the beginning of the secondary winding of the transformer, the end of which is connected to the source of the MOS transistor and through the resistor to the bases of transistors whose collectors are connected through diodes in the unlocking direction to the gate of the MOS transistor (RF patent No. 2337473), which is selected as a prototype.

The disadvantage of this key is the bipolar control of the MOS transistor, which reduces its resistance to the SEGR effect and leads to a decrease in reliability (Ivanov N.A., Mitin E.V., Pashuk V.V., Tverskoy M.G. SEGR effect in MIS transistors irradiated with protons. Radiation resistance of electronic systems, "Resistance - 2010", scientific and technical collection, issue 13, M., 2010, pp. 95-96).

The aim of the invention is to increase reliability.

This goal is achieved by the fact that in the power key on the MOS transistor containing the transformer, the end of the secondary winding of which is connected to the source of the MOS transistor; diodes and a resistor, the anode of the first diode connected to the beginning of the secondary winding of the transformer, and the cathode with the gate of the MOS transistor; the first capacitor is introduced, which is connected between the gate and the source of the MOS transistor, the cathode of the second diode is connected to the beginning of the secondary winding of the transformer, and the anode is connected through the resistor with the gate of the MOS transistor; a second capacitor is introduced, which is connected between the anode of the second diode and the source of the MOS transistor.

The drawing shows a circuit diagram of a power switch on an MOS transistor.

The power switch on the MOS transistor contains a transformer (1) with a primary winding (2) and a secondary winding (3), the end of which is directly connected to the source of the MOS transistor (4); the first diode (5), the anode of which is connected to the beginning of the secondary winding (3), and the cathode to the gate of the MOS transistor (4), between the gate and the source of which a capacitor (6) is connected; the second diode (7), the cathode of which is connected to the beginning of the secondary winding (3), and the anode through the resistor (8) - to the gate of the MOS transistor (4); a capacitor (9), which is connected between the anode of the diode (7) and the source of the MOS transistor (4).

The device operates as follows.

When applying to the input of the device on the primary winding (2) of the transformer (1) short positive pulses with high duty cycle, the secondary positive windings (3) also have short positive pulses with high duty cycle.

Positive pulses from the beginning of the secondary winding (3) through the diode (5) go to the capacitor (6) and the gate of the MOS transistor (4), the capacitor (6) and the gate-source capacitance of the MOS transistor charge (4), and it opens .

In the pause between short positive pulses on the secondary winding (3), there is a small negative voltage, which does not pass the diode (5) to the gate of the MOS transistor (4); The diode (7), opening up, charges the capacitor (9) to a small negative voltage, the value of which is not enough to discharge the capacitor capacitance (6) and the gate-source of the MOS transistor (4) through the resistor (8), and it remains open.

When short negative pulses with a high duty cycle are applied to the primary winding of the transformer (1) at the input of the device (2), short negative pulses also appear on the secondary winding, which charge the capacitor (9) to a negative voltage - the capacitor (6) discharges through the resistor (8) to a value close to zero, and the MOS transistor closes.

In the pause between short negative pulses on the secondary winding (3), there is a small positive voltage, which, opening the diode (5), does not allow the gate-source voltage of the MOS transistor (4) to become negative, and close to zero - positive, and MIS transistor (4) remains closed.

In the proposed device, the appearance of a negative voltage on the gate of an MOS transistor (4) is eliminated and, therefore, reliability is increased when exposed to heavy charged particles.

A prototype device was assembled on: transformer TIL2 V (1); MOS transistor (4) 2P7160 V; diodes (5) and (7) 2D510A; capacitors (6) and (9) 0.1 μF; 6.8 kΩ resistor.

When controlling pulses with an amplitude of 10 V for a duration of 8 μs and a period of 42 μs, the on-off time was 100 μs, U si max = 7.5 V, U si min = 0.4 V.

Of the patent information materials known to the applicant, no signs were found that are similar to the totality of the features of the claimed object.

Claims (1)

A power switch on an MOS transistor, containing a transformer whose end of the secondary winding is connected directly to the source of the MOS transistor, two diodes, the cathode of one of which is connected directly to the gate of the MIS transistor, and a resistor, characterized in that the anode of the first diode and the cathode of the second the diode is connected to the beginning of the secondary winding of the transformer, the anode of the second diode is connected through a resistor to the gate of the MOS transistor; two capacitors are introduced, the first is connected between the gate and the source of the MOS transistor, the second is between the anode of the second diode and the source of the MOS transistor.