Power transistor control device
The power transistor driver, equipped with a turn-on transformer, turn-off transformer, and Darlington circuit, addresses duty cycle and reliability issues, enabling broader application and improved reliability in push-pull circuits with reduced radiation exposure.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- AKTSIONERNOE OBSHCHESTVO INFORMATSIONNYE SPUTNIKOVYE SISTEMY IMENI AKADEMIKA M F RESHETNEVA (AO RESHETNEV)
- Filing Date
- 2025-12-23
- Publication Date
- 2026-06-30
AI Technical Summary
Existing power transistor drivers face limitations in duty cycle, reliability, and power supply requirements, restricting their application in push-pull converter circuits and exposing transistors to radiation and heavy charged particles.
The driver incorporates a power transistor turn-on transformer, a turn-off transformer with a reverse diode, a Darlington transistor circuit, and a field-effect transistor to amplify the control signal, enabling active locking and unipolar power supply, simplifying the control circuit and enhancing reliability.
This configuration expands the driver's applicability to push-pull circuits, improves reliability by active locking, and simplifies the power supply, ensuring efficient operation with reduced radiation exposure.
Smart Images
Figure 00000001_ABST
Abstract
Description
[0001] The invention relates to the field of electrical engineering, in particular to the development of pulse converters of electrical energy as a driver for controlling a power transistor.
[0002] Analysis of the Russian patent database revealed a number of analogues. Known is the "Method for controlling a semiconductor switch" (patent RU2290737). The method for controlling a semiconductor switch with isolated input and output sections and a coupling transformer based on the electromagnetic effect between them, consisting in converting the supply voltage of the input section into current pulses through the input section of the coupling transformer, with limiting the amplitude of the current pulses by adjusting their duration and repetition rate and isolating the newly converted control signal of the semiconductor switch at the output section of the coupling transformer, characterized in that the rise time of the amplitude of the current pulses through the input section of the coupling transformer to a specified level with a duration not exceeding the critical value is set, and to turn the semiconductor switch on or off, or maintain it in the on or off state, they control after a specified time interval,counted from the moment the voltage of one direction, allocated from the output section of the coupling transformer, reaches the first threshold level, the fact that the allocated voltage of one direction exceeds the second threshold level, wherein the first threshold level is set not exceeding the threshold voltage of the semiconductor switch, and the second threshold level is set exceeding the minimum permissible control voltage of the semiconductor switch, and based on the results of the control, the voltage of one direction, allocated from the side of the output section of the coupling transformer in the control circuit of the semiconductor switch is adjusted.
[0003] The disadvantage of this technical solution is that the minimum open phase time is at least 2 μs, which reduces the minimum duty cycle at a frequency of 100 kHz to 20%.
[0004] Also known is the "Power Switch Gate Driver" (patent RU168275). The driver comprises a transformer, the primary winding of which is connected to a contact providing sufficient inflow and outflow currents to control the power switch. The secondary winding is connected through a series resistor to the gate and source of the power switch, between which a double-sided zener diode is connected. An additional MOSFET, the gate and drain of which are connected to the primary winding of the transformer, and the source connected to the common terminal of the driver, is also connected by a diode, whose anode is connected to the drain of the MOSFET and the cathode is connected to the positive supply terminal of the driver.
[0005] The disadvantage of this technical solution is that the maximum duty cycle of the control pulse is limited to 50%, which limits the scope of application of this device. In addition, a negative voltage is applied to the gate of the controlled field-effect transistor at the moment of locking, which reduces the resistance of the controlled transistor to the accumulated dose of radiation and to heavy charged particles.
[0006] Also known is the "Power Transistor Control Device" (patent RU2809191). The power transistor control device comprises a key-opening transformer, the primary winding of which is connected between the input control signal supply point and the common point of the circuit, the secondary winding of which is connected through a series-connected current-limiting resistor between the gate and the source of the controlled key, a diode is installed between the secondary winding and the current-limiting resistor with the cathode to the resistor, a circuit is added consisting of a locking transformer, the secondary winding of which is shunted by a reverse diode and generates a pulse that controls the locking transistor, connected between the gate and the source of the controlled transistor;the primary winding is connected to the supply point of the circuit through a resistor and to the output of the comparator, the inverting input of which is connected directly to the common point of the circuit, the non-inverting input is connected through a series resistive-capacitive circuit to the point of supply of the control input signal and through a resistor to the supply point of the circuit, and through a resistor and a diode parallel to it to the common point of the circuit.
[0007] The specified device is the closest in technical essence and is accepted as a prototype.
[0008] A disadvantage of this technical solution is the lack of active locking of the controlled power transistor, which can lead to its unauthorized unlocking in the presence of drain-to-source voltage changes. This precludes the use of this driver in the design of push-pull converter circuits. A comparator is used in the turn-off pulse generator circuit, necessitating a bipolar power supply in the driver. The generator circuit lacks a control signal amplifier, requiring the generation of a control signal with a high pulse current.
[0009] The following essential features have been identified for the claimed invention in common with the prototype: the power transistor control device comprises a power transistor turn-on transformer, the primary winding of which is connected to the point of supplying the input control signal, the secondary winding of which is connected through a series current-limiting resistor between the gate and the source of the controlled power transistor; a diode is installed between the secondary winding and the current-limiting resistor with the cathode facing the resistor;a locking transformer, the secondary winding of which is shunted by a reverse diode that forms a pulse, controlling a locking transistor connected between the gate and the source of the controlled power transistor, the primary winding of the locking transformer is connected to the power supply point of the circuit through a resistor, the input of the locking pulse former is connected through a series resistive-capacitive circuit to the point of supplying the control signal and through a resistor and a diode parallel to it - to the common point of the circuit;
[0010] The technical problem that the invention is aimed at solving is expanding the scope of application of the driver and increasing its reliability.
[0011] The technical result is an expansion of the scope of application of the driver in push-pull circuits due to the presence of active locking, a simplification of the driver power supply circuit and a simplification of the control circuits due to the introduction of an amplifier into the driver.
[0012] The technical result is achieved and the technical problem is solved due to the fact that the power transistor control device comprises a power transistor turn-on transformer, the primary winding of which is connected to the point of supplying the input control signal, the secondary winding of which is connected through a series current-limiting resistor between the gate and the source of the controlled power transistor; a diode is installed between the secondary winding and the current-limiting resistor with the cathode to the resistor; a turn-off transformer, the secondary winding of which is shunted by a reverse diode that forms a pulse, controlling the turn-off transistor, connected between the gate and the source of the controlled power transistor, the primary winding of the turn-off transformer is connected to the power supply point of the circuit through a resistor,the input of the turn-off pulse generator is connected through a series resistive-capacitive circuit to the point where the control signal is supplied and through a resistor and a diode parallel to it to the common point of the circuit; the turn-off trigger transistor is connected between the gate and the source of the turn-off transistor; the turn-off trigger diode is connected in series with the gate of the turn-off transistor; the midpoint of a resistive-capacitive divider is connected to the gate of the turn-off transistor, the resistor of which is connected to the point where the sources of the controlled power transistor, the turn-off transistor and the turn-off trigger transistor are combined, where the turn-off transistor and the diode connected to its gate are components of the turn-off trigger; the capacitor of the divider is connected between the secondary winding of the turn-off transformer and the anode of the series diode; the turn-off pulse generator is represented as a pair of bipolar transistors connected in a Darlington circuit; a field-effect transistor that amplifies the input control signal,connected between the control signal supply point, the common point of the circuit and the terminal of the primary winding of the gate transformer opposite to that connected to the power supply point through a current-limiting resistor.
[0013] Unipolar power supply of the driver is achieved by replacing the comparator with a Darlington transistor circuit, connected to the input through a series resistive-capacitive circuit to the point of supplying the amplified control signal, and through a resistor and a diode parallel to it - to the common point of the circuit.
[0014] The input control pulse is amplified by connecting a field-effect transistor between the control signal supply point, the common point of the circuit, and the terminal of the primary winding of the gate transformer, opposite to the one connected to the power supply point through a current-limiting resistor, which amplifies the input control signal.
[0015] The invention is explained by a diagram, where Fig. 1 shows a functional diagram of a power transistor control device.
[0016] The power transistor control device comprises a transistor turn-on transformer 1, the primary winding of which is connected to the point of supplying the input amplified control signal, a demagnetizing resistor 2 is connected in parallel to the primary winding, the secondary winding is connected through a series-connected current-limiting resistor 3 between the gate 8 and the source 9 of the controlled power transistor. Between the secondary winding and the current-limiting resistor 3, a diode 4 is installed with the cathode to the resistor 3. A blocking transformer 5, the secondary winding of which is shunted by a freewheeling diode 6, generates a pulse that controls a blocking transistor 7, connected between the gate 8 and the source 9 of the controlled power transistor. The primary winding of the blocking transformer 5 is connected to the power supply point of the circuit 10 through a resistor 11.The input of the turn-off pulse generator 21 is connected through a series resistive 12 - capacitive 13 circuit to the point of supply of the amplified control input signal 22 and through a resistor 14 and a diode 15 parallel to it - to the common point of the circuit 16. Between the gate and the source of the turn-off transistor 7, the transistor 17 of the turn-off trigger is connected, and in series with the gate of the turn-off transistor 7, the diode 18 of the turn-off trigger is connected (the components of the turn-off trigger), the midpoint of the resistive-capacitive divider is connected to the gate of the turn-off transistor 7, the resistor 19 of which is connected to the point of combining the sources of the controlled power transistor, the turn-off transistor 7 and the transistor 17 of the turn-off trigger, and the capacitor 20 is connected between the secondary winding of the turn-off transformer 1 and the anode of the series diode 4. The turn-off pulse generator 21 is shown in the form of a pair of bipolar transistors connected according to the Darlington circuit.Between the control signal supply point 22, the common point of the circuit 16 and the terminal of the primary winding of the unlocking transformer 1, opposite to that which is connected to the power supply point 10 through the current-limiting resistor 23, a field-effect transistor 24 is connected, amplifying the input control signal.
[0017] The proposed device functions as follows.
[0018] When a power transistor turn-on pulse is applied to control input 22, this pulse is amplified by input field-effect transistor 24 and applied to the primary winding of transformer 1, which turns on the power transistor. This voltage is then transformed into a secondary winding voltage, which, via capacitor 20, turns on transistor 17 of the turn-off flip-flop. This keeps turn-off transistor 7 off and allows the gate 8-source 9 capacitor of the controlled power transistor to be charged via diode 4 and current-limiting resistor 3. Also, the voltage supplied to the control input 22 unlocks the amplifying field-effect transistor 24 and, since the voltage on the capacitor 13 cannot change instantly, a voltage equal to the supply voltage taken with a minus sign must be applied to the input base of the Darlington cascade of the turn-off pulse generator 21, however, the reverse diode 15 limits this voltage to a level of no more than 0.7 V.Over time, capacitor 13 discharges through series resistor 12 to zero voltage. The current through the Darlington stage of turn-off pulse generator 21 is zero, and therefore, the voltage applied to the primary winding of turn-off transformer 5 is zero.
[0019] When the high voltage level is removed from control input 22, amplifying field-effect transistor 24 is turned off. Demagnetizing currents arise in transformer 1, generating a reverse voltage surge across the windings. However, reverse-biased diode 4, connected in series with current-limiting resistor 3, prevents the negative voltage generated by transformer 1 from being applied to the gate of transistor 24. At the same time, the alternating component of the said demagnetizing signal is applied through capacitor 20 to resistor 19 and the gate of transistor 17 of the turn-off trigger, switching it (transistor 17 of the turn-off trigger) to the off state, which creates one of the conditions for active turn-off.In this case, capacitor 13, discharged to zero, passes the entire voltage to the base of the Darlington cascade until capacitance 13 recharges through another series resistor 14, forming a short pulse in the primary winding of transformer 5, which turns on transistor 7, through which the gate capacitance of the controlled power transistor discharges to zero. Diode 18, connected between the secondary winding of transformer 5 and the gate of turn-off transistor 7, maintains a positive voltage on the gate of transistor 7. Turn-off trigger transistor 17, also connected there, being in the off state, holds turn-off transistor 7 open until a high-level control voltage arrives at the input of driver 22. Then the process is repeated.
Claims
A power transistor control device comprising a power transistor turn-on transformer, the primary winding of which is connected to the control input signal supply point, the secondary winding of which is connected through a series current-limiting resistor between the gate and the source of the controlled power transistor; a diode is installed between the secondary winding and the current-limiting resistor with its cathode facing the resistor; a turn-off transformer, the secondary winding of which is shunted by a reverse diode that generates a pulse, controlling the turn-off transistor connected between the gate and the source of the controlled power transistor, the primary winding of the turn-off transformer is connected to the circuit supply point through a resistor, the input of the turn-off pulse generator is connected through a series resistive-capacitive circuit to the control signal supply point and through a resistor and a diode parallel to it - to a common point of the circuit, characterized in that,that a turn-off trigger transistor is connected between the gate and the source of the turn-off transistor, a turn-off trigger diode is connected in series with the gate of the turn-off transistor, the midpoint of a resistive-capacitive divider is connected to the gate of the turn-off transistor, the resistor of which is connected to the junction point of the sources of the controlled power transistor, the turn-off transistor and the turn-off trigger transistor, where the turn-off transistor and the diode connected to its gate are components of the turn-off trigger; the capacitor of the divider is connected between the secondary winding of the turn-off transformer and the anode of the series diode; the turn-off pulse generator is represented in the form of a pair of bipolar transistors connected in a Darlington circuit; a field-effect transistor that amplifies the input control signal is connected between the control signal supply point, the common point of the circuit and the terminal of the primary winding of the turn-off transformer opposite to that,which is connected to the power supply point through a current-limiting resistor.