Tacked transistor switching device

Abstract

A spliced transistor switching device comprises a transistor switching assembly, a transistor switching circuit and a microcontroller, and the transistor switching circuit comprises a first transistor switching sub-circuit and a second transistor switching sub-circuit. A second on-resistance value of the second transistor switch sub-circuit is greater than a first on-resistance value of the first transistor switch sub-circuit. When the microcontroller switches on the first transistor switch sub-circuit, the transistor switch assembly is switched on; when the microcontroller switches on the second transistor switch sub-circuit, the transistor switch assembly is switched on. When the microcontroller receives a switching-off signal, the microcontroller is configured to sequentially cut off the first transistor switching sub-circuit and the second transistor switching sub-circuit.

Description

Technical Field

[0001] This disclosure relates to a transistor switching device, and more particularly to a stacked transistor switching device. Background Technology

[0002] High-speed switching of transistors can cause voltage surges that can damage the device. This is because there is parasitic inductance on the wires. When the current changes suddenly (e.g., when the device is turned off), the flyback voltage (freewheeling electromotive force) of the inductor can cause great risks, such as device damage. This problem urgently needs to be solved. Summary of the Invention

[0003] To address the aforementioned problems, the present disclosure aims to provide a stacked transistor switching device.

[0004] To achieve the aforementioned objectives of this disclosure, the stacked transistor switching device of this disclosure includes: a transistor switching assembly; a transistor switching circuit electrically connected to the transistor switching assembly, wherein the transistor switching circuit and the transistor switching assembly are connected in series; and a microcontroller electrically connected to the transistor switching assembly and the transistor switching circuit, wherein the transistor switching circuit includes: a first transistor switching sub-circuit electrically connected to the transistor switching assembly and the microcontroller; and a second transistor switching sub-circuit electrically connected to the transistor switching assembly and the microcontroller. A transistor switching subcircuit and a microcontroller are provided. The second transistor switching subcircuit and the first transistor switching subcircuit are connected in parallel. A second on-resistance value of the second transistor switching subcircuit is greater than a first on-resistance value of the first transistor switching subcircuit. When the microcontroller turns on the first transistor switching subcircuit, the transistor switching component is turned on. When the microcontroller turns on the second transistor switching subcircuit, the transistor switching component is turned on. When the microcontroller receives a cut-off switch signal, the microcontroller is configured to sequentially turn off the first transistor switching subcircuit and the second transistor switching subcircuit to turn off the transistor switching component.

[0005] Furthermore, in a specific embodiment of the stacked transistor switching device of the present disclosure as described above, the stacked transistor switching device further includes: a voltage detector electrically connected to the transistor switching assembly, the microcontroller, and the transistor switching circuit, wherein the voltage detector is configured to detect a first voltage at a connection point between the transistor switching assembly and the transistor switching circuit and notify the microcontroller of the first voltage; when the microcontroller receives the off-switch signal, if the first voltage is positive, the microcontroller is configured to sequentially disconnect the first transistor switching sub-circuit and the second transistor switching sub-circuit to disconnect the transistor switching assembly.

[0006] Furthermore, in a specific embodiment of the stacked transistor switching device of the present disclosure as described above, when the microcontroller receives the cut-off switch signal, if the first voltage is negative, the microcontroller is configured to enter a rectification mode; in the rectification mode, when the first voltage changes from positive to negative, the microcontroller is configured to sequentially turn on the second transistor switching sub-circuit and the first transistor switching sub-circuit; in the rectification mode, during the process of the first voltage changing from negative to zero, the microcontroller is configured to sequentially turn off the first transistor switching sub-circuit and the second transistor switching sub-circuit to cut off the transistor switching assembly.

[0007] Furthermore, in a specific embodiment of the stacked transistor switching device of this disclosure as described above, the transistor switching circuit further includes: a third transistor switching sub-circuit electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, the microcontroller, and the voltage detector; and a fourth transistor switching sub-circuit electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, the third transistor switching sub-circuit, the microcontroller, and the voltage detector, wherein the first transistor switching sub-circuit, the second transistor switching sub-circuit, the third transistor switching sub-circuit, and the fourth transistor switching sub-circuit are electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, the third transistor switching sub-circuit, the microcontroller, and the voltage detector. The four transistor switching subcircuits are connected in parallel. The fourth on-resistance value of the fourth transistor switching subcircuit is greater than the third on-resistance value of the third transistor switching subcircuit, and the third on-resistance value of the third transistor switching subcircuit is greater than the second on-resistance value of the second transistor switching subcircuit. When the microcontroller turns on the third transistor switching subcircuit, the transistor switching assembly is turned on. When the microcontroller turns on the fourth transistor switching subcircuit, the transistor switching assembly is turned on. When the microcontroller receives a turn-on switch signal, the microcontroller is configured to sequentially turn on the fourth transistor switching subcircuit, the third transistor switching subcircuit, the second transistor switching subcircuit, and the first transistor switching subcircuit. Furthermore, in the absence of the voltage detector, when the microcontroller receives the turn-off switch signal, it will disregard the first voltage and is configured to sequentially turn off the first transistor switching subcircuit, the second transistor switching subcircuit, the third transistor switching subcircuit, and the fourth transistor switching subcircuit to turn off the transistor switching assembly.

[0008] Furthermore, in a specific embodiment of the stacked transistor switching device of the present disclosure as described above, when the microcontroller receives the cut-off switch signal, if the first voltage is positive, the microcontroller is configured to sequentially cut off the first transistor switch sub-circuit, the second transistor switch sub-circuit, the third transistor switch sub-circuit, and the fourth transistor switch sub-circuit to cut off the transistor switching assembly.

[0009] Furthermore, in a specific embodiment of the stacked transistor switching device of the present disclosure as described above, in the rectification mode, when the first voltage changes from positive to negative, the microcontroller is configured to sequentially turn on the fourth transistor switching sub-circuit, the third transistor switching sub-circuit, the second transistor switching sub-circuit, and the first transistor switching sub-circuit; in the rectification mode, during the process of the first voltage changing from negative to zero, the microcontroller is configured to sequentially turn off the first transistor switching sub-circuit, the second transistor switching sub-circuit, the third transistor switching sub-circuit, and the fourth transistor switching sub-circuit to turn off the transistor switching assembly.

[0010] Furthermore, in a specific embodiment of the stacked transistor switching device of the present disclosure as described above, the first transistor switching sub-circuit includes: a first metal-oxide-semiconductor field-effect transistor, which is electrically connected to the transistor switching assembly, the second transistor switching sub-circuit, the third transistor switching sub-circuit, the fourth transistor switching sub-circuit, the microcontroller, and the voltage detector.

[0011] Furthermore, in a specific embodiment of the stacked transistor switching device of this disclosure as described above, the second transistor switching sub-circuit includes: a second metal-oxide-semiconductor field-effect transistor (MOSFET), which is electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the third transistor switching sub-circuit, the fourth transistor switching sub-circuit, the microcontroller, and the voltage detector; and a second resistor, which is electrically connected to the second MOSFET. The third transistor switching sub-circuit includes: a third MOSFET, which is electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, and the third transistor switching sub-circuit. The fourth transistor switching subcircuit includes: a fourth MOSFET electrically connected to the transistor switching assembly, the first transistor switching subcircuit, the second transistor switching subcircuit, the third transistor switching subcircuit, the microcontroller, and the voltage detector; and a fourth resistor electrically connected to the fourth MOSFET, wherein a fourth resistance value of the fourth resistor is greater than a third resistance value of the third resistor, and the third resistance value of the third resistor is greater than a second resistance value of the second resistor.

[0012] Furthermore, in a specific embodiment of the stacked transistor switching device of the present disclosure as described above, the first transistor switching sub-circuit further includes: a first resistor electrically connected to the first metal-oxide-semiconductor field-effect transistor, wherein the second resistance value of the second resistor is greater than the first resistance value of the first resistor.

[0013] Furthermore, in a specific embodiment of the stacked transistor switching device of the present disclosure as described above, the transistor switching component is a gallium nitride field-effect transistor or a silicon carbide field-effect transistor.

[0014] The benefit of this disclosure is to mitigate switching actions to reduce high-voltage surges and protect components.

[0015] To further understand the techniques, methods, and effects of this disclosure and to achieve the intended purposes of this disclosure, please refer to the following detailed description and accompanying drawings; furthermore, the purposes, features, and characteristics of this disclosure can be understood in greater depth and specificity; however, the accompanying drawings are provided for reference and description only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0016] Figure 1 This is a circuit block diagram of the stacked transistor switching device disclosed herein.

[0017] Figure 2This is a schematic diagram of the reverse current of this disclosure. Detailed Implementation

[0018] Numerous specific details are provided in this disclosure to provide a thorough understanding of embodiments thereof; however, those skilled in the art will appreciate that this disclosure may be practiced without one or more of these specific details; in other instances, well-known details have not been shown or described to avoid obscuring the features of this disclosure. The technical content and detailed description of this disclosure are as follows, and are illustrated with accompanying drawings.

[0019] Please refer to Figure 1 This is a circuit block diagram of the stacked transistor switching device 10 of this disclosure. The stacked transistor switching device 10 of this disclosure includes a transistor switching assembly 102, a transistor switching circuit TS, a voltage detector 106, and a microcontroller 104. The transistor switching circuit TS includes a first transistor switching sub-circuit TS1, a second transistor switching sub-circuit TS2, a third transistor switching sub-circuit TS3, and a fourth transistor switching sub-circuit TS4. The first transistor switching sub-circuit TS1 includes a first metal-oxide-semiconductor field-effect transistor SW1 and a first resistor R1. The second transistor switching circuit TS2 includes a second metal-oxide-semiconductor field-effect transistor SW2 and a second resistor R2. The third transistor switching circuit TS3 includes a third metal-oxide-semiconductor field-effect transistor SW3 and a third resistor R3. The fourth transistor switching circuit TS4 includes a fourth metal-oxide-semiconductor field-effect transistor SW4 and a fourth resistor R4. The above components are electrically connected to each other.

[0020] Figure 1 It also displays a switching current I1, a driving voltage point V1, and a second voltage point Vss. The transistor switching component 102 is a gallium nitride field-effect transistor or a silicon carbide field-effect transistor; the first transistor switching sub-circuit TS1, the second transistor switching sub-circuit TS2, the third transistor switching sub-circuit TS3, and the fourth transistor switching sub-circuit TS4 can be silicon metal oxide field-effect transistors.

[0021] The transistor switching circuit TS and the transistor switching assembly 102 are connected in series; the first transistor switching sub-circuit TS1, the second transistor switching sub-circuit TS2, the third transistor switching sub-circuit TS3, and the fourth transistor switching sub-circuit TS4 are connected in parallel. The fourth on-resistance value of the fourth transistor switching sub-circuit TS4 is greater than the third on-resistance value of the third transistor switching sub-circuit TS3, the third on-resistance value of the third transistor switching sub-circuit TS3 is greater than the second on-resistance value of the second transistor switching sub-circuit TS2, and the second on-resistance value of the second transistor switching sub-circuit TS2 is greater than the first on-resistance value of the first transistor switching circuit TS1; the fourth resistance value of the fourth resistor R4 is greater than the third resistance value of the third resistor R3, the third resistance value of the third resistor R3 is greater than the second resistance value of the second resistor R2, and the second resistance value of the second resistor R2 is greater than the first resistance value of the first resistor R1. Note: Figure 1 The above content is only one embodiment of this disclosure and is not intended to limit this disclosure; the metal-oxide-semiconductor field-effect transistor and its paired resistor should be considered as a whole. For example, the first metal-oxide-semiconductor field-effect transistor SW1 and the first resistor R1 should be considered as a whole (considered as the first transistor switching sub-circuit TS1), and the overall resistance exhibited by the first transistor switching sub-circuit TS1 is a result, which is the resistance value of the first metal-oxide-semiconductor field-effect transistor SW1 plus the resistance value of the first resistor R1.

[0022] For the first transistor switching sub-circuit TS1, the second transistor switching sub-circuit TS2, the third transistor switching sub-circuit TS3, and the fourth transistor switching sub-circuit TS4, each transistor switching sub-circuit can conduct under positive voltage conditions. However, the resistance value of the transistor switching sub-circuit determines a maximum conductable current. As the current increases, a first voltage VD rises until it approaches the cutoff voltage of the transistor switching assembly 102. At this point, the transistor switching assembly 102 gradually turns off (impedance increases) until the current no longer increases, thus balancing at a specific current. For example, the on-resistance of the first transistor switching sub-circuit TS1 is much smaller than the on-resistance of the transistor switching assembly 102 (commonly referred to as Rdson), and the on-resistance of the second transistor switching sub-circuit TS2 is much larger than the on-resistance of the transistor switching assembly 102 (commonly referred to as Rdson). Therefore, if the first transistor switching sub-circuit TS1 is not conducting, the transistor switching assembly 102 cannot be considered fully conducting. The voltage detector 106 is configured to detect the first voltage VD at a connection point P1 between the transistor switching assembly 102 and the transistor switching circuit TS, and to notify the microcontroller 104 of the first voltage VD. A resistor (not shown) may also be provided between the connection point P1 and the voltage detector 106. Figure 1 ).

[0023] When the microcontroller 104 receives a switching signal S1, the microcontroller 104 is configured to sequentially turn on the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), and the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1) so that the overall impedance of the transistor switching circuit TS gradually decreases. In the absence of the voltage detector 106, when the microcontroller 104 receives a cut-off switch signal S2, it will disregard the first voltage VD and will be configured to sequentially cut off the first transistor switch sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1), the second transistor switch sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), the third transistor switch sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), and the fourth transistor switch sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4) to cut off the transistor switch assembly 102.

[0024] When the microcontroller 104 receives the cut-off switch signal S2, if the first voltage VD is positive, the microcontroller 104 is configured to sequentially cut off the first transistor switch sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1), the second transistor switch sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), the third transistor switch sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), and the fourth transistor switch sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4) so ​​that the overall impedance of the transistor switch circuit TS gradually increases to achieve a gentle cut-off of the transistor switch assembly 102.

[0025] When the microcontroller 104 receives the cut-off switch signal S2, if the first voltage VD is negative, the microcontroller 104 is configured to enter a rectification mode. In this rectification mode, when the first voltage VD changes from positive to negative, the microcontroller 104 is configured to sequentially turn on the fourth transistor switch sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4), the third transistor switch sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), the second transistor switch sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), and the first transistor switch sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1), so that the overall impedance of the transistor switch circuit TS gradually decreases. In this rectification mode, during the process of the first voltage VD changing from negative to zero, the microcontroller 104 is configured to sequentially disconnect the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), and the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4) so ​​that the overall impedance of the transistor switching circuit TS gradually increases to disconnect the transistor switching assembly 102.

[0026] During the operation of the stacked transistor switching device 10 (but there is no limitation before or after the operation of the stacked transistor switching device 10): the upper component (i.e., the transistor switching component 102) is high voltage resistant and has a gate voltage Vg (relative to the circuit ground), which is greater than a cutoff voltage (commonly referred to as Vth); during the operation of the stacked transistor switching device 10, the gate voltage Vg is generally greater than the cutoff voltage, and a gate-source voltage (commonly referred to as Vgs) is controlled by the change of a source voltage Vs. The gate-source voltage is reduced by increasing the source voltage Vs. When the gate-source voltage is less than the cutoff voltage, the transistor switching component 102 is turned off.

[0027] The impedance of the lower components (i.e., the first transistor switching sub-circuit TS1, the second transistor switching sub-circuit TS2, the third transistor switching sub-circuit TS3, and the fourth transistor switching sub-circuit TS4) is controlled to change the source voltage Vs to control the operation of the stacked transistor switching device 10. When the stacked transistor switching device 10 is on, the impedance of the lower components must be low. Therefore, the difficulty in controlling the rate of current change lies in controlling a low-impedance component in a relatively high-impedance state. This disclosure uses a series of switchable resistors with different impedances connected in parallel to form the lower components, and uses individual switch selection to precisely control the impedance of the lower components of the stacked structure.

[0028] One of the features of this disclosure is its rectification applications; for example, in synchronous rectification applications, the induced electromotive force on the secondary side drives a reverse current Ir (e.g., Figure 2 (As shown); at this time, the first voltage VD (relative to the second voltage point Vss) is negative. The microcontroller 104 detects that the first voltage VD changes from positive to negative through the voltage detector 106. The microcontroller 104 can sequentially turn on the fourth transistor switching sub-circuit TS4 (that is, the fourth metal-oxide-semiconductor field-effect transistor SW4), the third transistor switching sub-circuit TS3 (that is, the third metal-oxide-semiconductor field-effect transistor SW3), the second transistor switching sub-circuit TS2 (that is, the second metal-oxide-semiconductor field-effect transistor SW2), and the first transistor switching sub-circuit TS1 (that is, the first metal-oxide-semiconductor field-effect transistor SW1) as needed. When the inductor's energy is about to be depleted, the current approaches zero, and the first voltage VD also changes from negative to zero. When the first voltage VD is detected to be approaching zero, the microcontroller 104 can sequentially cut off the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), and the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4) as needed. The main function of the voltage detector 106 is to add a rectification mode in addition to the original complete switching mode.

[0029] Please refer to Figure 2 This is a schematic diagram of the reverse current Ir disclosed herein. Figure 2The circuit features a drain (D), gate (G), and source (S). The upper component is a high-voltage depletion-mode gallium nitride (GaN) high-electron-mobility transistor (HEP) or silicon carbide (SiC) MOSFET, while the lower component is a low-voltage silicon metal-oxide-semiconductor (SiO2) MOSFET (e.g., an N-type SiO2 MOSFET). The upper component has a fixed gate-source cutoff voltage; if the gate-source voltage is below the cutoff voltage, it is not conducting; conversely, if the gate-source voltage is above the cutoff voltage, it conducts. When on, the lower component is conducting (low impedance), causing the gate-source voltage of the upper component to approach zero, thus turning the upper component on. When off, the high impedance of the N-type SiO2 MOSFET creates a voltage across its impedance, resulting in a negative gate-source voltage for the upper component. This negative voltage, sufficiently large to exceed the cutoff voltage (typically -10 to -20 volts), turns the upper component off. Therefore, controlling the lower SiO2 MOSFET determines the on / off state of the upper component; this forms a high-voltage switch, which can be used for applications such as switching power conversion. The lower the impedance of the entire switch when it is on, the better. Therefore, the on-resistance (usually called Rdson) of both the upper and lower components should be as low as possible. By controlling the impedance of the lower component (e.g., on when low impedance, off when high impedance), the state of the gate-source voltage of the upper component is controlled, thus controlling the conduction and cutoff of the entire architecture. Only when the lower component has a relatively high resistance value will the drain voltage have sufficient influence to affect the gate-source voltage and turn off the upper component. Here, "relatively high" resistance value refers to low impedance relative to the switch's on-resistance.

[0030] If the aforementioned transistor switching sub-circuit (e.g., the first transistor switching sub-circuit TS1) requires low impedance, it can be achieved using the on-resistance (commonly referred to as Rdson) of the metal-oxide-semiconductor field-effect transistor (e.g., the first metal-oxide-semiconductor field-effect transistor SW1). If a higher resistance value is required, it can be achieved by adding a resistor (e.g., the first resistor R1) to the metal-oxide-semiconductor field-effect transistor (e.g., the first metal-oxide-semiconductor field-effect transistor SW1). In other words, each transistor switching sub-circuit is a switchable impedance.

[0031] The sequential activation of the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), and the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1) can also be configured with an extended time and controlled speed. Furthermore, the sequential deactivation of the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), and the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4) can be interrupted or reversed at any time, depending on the requirements.

[0032] Metal-oxide-semiconductor (MOSFET) field-effect transistors (FETs) can be internal components of integrated circuits (ICs), external components, or a combination of both. For example, one or two low-impedance external discrete N-type FETs can form a parallel impedance series with several internal N-type FETs of the IC. The external discrete FETs can have a common drain structure, with different gate signals controlling different source paths. ICs, gallium nitride (GaN) FETs, or external FETs can all be packaged in the same package.

[0033] The lower component consists of two or more switchable impedances connected in parallel; additionally, a fixed resistor can be connected in parallel (this is required for existing conduction leakage current and is not shown in these diagrams). The microcontroller 104 can internally be configured with one or more comparators to detect the voltage level of the first voltage VD; when the first voltage VD is negative (entering rectification mode), the comparator level can determine whether individual resistors are turned on or off; each resistor switch can be assigned an individual on level and an off level. When the first voltage VD changes from positive to negative, the microcontroller 104 is configured to sequentially turn on the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), and the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1). Therefore, the possible on / off levels, from largest to smallest, are the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), and the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1). During the process of the first voltage VD changing from negative to zero, the microcontroller 104 is configured to sequentially turn off the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), and the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4). Therefore, the possible switch levels, from largest to smallest, are the fourth transistor switching sub-circuit TS4 (i.e., the fourth metal-oxide-semiconductor field-effect transistor SW4), the third transistor switching sub-circuit TS3 (i.e., the third metal-oxide-semiconductor field-effect transistor SW3), the second transistor switching sub-circuit TS2 (i.e., the second metal-oxide-semiconductor field-effect transistor SW2), and the first transistor switching sub-circuit TS1 (i.e., the first metal-oxide-semiconductor field-effect transistor SW1).

[0034] This disclosure uses four resistors divided into four levels as an example, but the number of resistor levels can be increased or simplified as needed. The minimally sized two switchable resistors have four possible combinations. Assuming the resistance of the first resistor is less than that of the second resistor, the first combination is that both the first and second resistors are conducting (this combination has the lowest resistance and is suitable for conducting). The second combination is that the first resistor is conducting but the second resistor is not conducting (but the resistance difference between this combination and the first combination is not significant, so it can be omitted). The third combination is that the first resistor is not conducting but the second resistor is conducting (suitable for interrupting the dynamic switching process of gallium nitride field-effect transistors). The fourth combination is that both the first and second resistors are not conducting (this combination has the highest resistance and is suitable for use when maintaining the off state).

[0035] The impedance of a series of resistors can be approximated by a ratio series. For example, the first resistor R1 is approximately 10 mΩ, the second resistor R2 is approximately 170 mΩ, the third resistor R3 is approximately 3 Ω, and the fourth resistor R4 is approximately 500 Ω. This example is approximately a ratio of 17. The ratio series is just a design aid concept, and the ratio value of the ratio series may vary depending on the number of resistor series and the system power. The fewer the series and the higher the power, the larger the ratio value may be. Generally speaking, the ratio value is approximately between 2 and 100.

[0036] The benefit of this disclosure is to mitigate switching actions to reduce high-voltage surges and protect components. This disclosure can also be described as a stepwise switching mechanism for cascaded structures. This disclosure utilizes digital control to precisely manage impedance changes across several orders of magnitude in the underlying component, thereby controlling the rate of change in the electrical current; it overcomes the challenge of controlling low-impedance components to operate at high impedance, a challenge stemming from the nonlinear characteristics of MOSFETs. For synchronous rectification applications, detecting the current cutoff timing is often a challenge; the higher the impedance of the underlying component, the higher the sensitivity of current detection. This disclosure assists the microcontroller 104 in accurately determining the zero-reaching time of the reverse current.

[0037] Although this disclosure has been described with reference to embodiments thereof, it should be understood that this disclosure is not limited to its details; various alternatives and modifications have been proposed in the foregoing description, and other alternatives and modifications will occur to those skilled in the art; therefore, all such alternatives and modifications are intended to be included within the scope of this disclosure.

[0038] [Symbol Explanation]

[0039] 10: Stacked transistor switching device

[0040] 102: Transistor Switching Assembly

[0041] 104: Microcontroller

[0042] 106: Voltage Detector

[0043] D: Drain electrode

[0044] G: Gate

[0045] I1: Switching current

[0046] Ir: Reverse current

[0047] P1: Connection point

[0048] R1: First resistor

[0049] R2: Second resistor

[0050] R3: Third resistor

[0051] R4: Fourth resistor

[0052] S: Source

[0053] S1: Switch signal

[0054] S2: Disconnect switch signal

[0055] SW1: First Metal-Oxide-Semiconductor Field-Effect Transistor

[0056] SW2: Second Metal-Oxide-Semiconductor Field-Effect Transistor

[0057] SW3: Third Metal-Oxide-Semiconductor Field-Effect Transistor

[0058] SW4: Fourth Metal-Oxide-Semiconductor Field-Effect Transistor

[0059] TS: Transistor Switching Circuit

[0060] TS1: First transistor switch sub-circuit

[0061] TS2: Second transistor switch circuit

[0062] TS3: Third transistor switch circuit

[0063] TS4: Fourth Transistor Switching Circuit

[0064] V1: Driving voltage point

[0065] VD: First voltage

[0066] Vg: Gate voltage

[0067] Vs: Source voltage

[0068] Vss: Second voltage point

Claims

1. A stacked transistor switching device, comprising: A transistor switching assembly; A transistor switching circuit, electrically connected to the transistor switching assembly, wherein the transistor switching circuit and the transistor switching assembly are connected in series; and A microcontroller, the microcontroller being electrically connected to the transistor switching assembly and the transistor switching circuit, in, The transistor switching circuit includes: A first transistor switching sub-circuit, electrically connected to the transistor switching assembly and the microcontroller; and A second transistor switch sub-circuit is electrically connected to the transistor switch assembly, the first transistor switch sub-circuit, and the microcontroller. The second transistor switch sub-circuit and the first transistor switch sub-circuit are connected in parallel. A second on-resistance value of the second transistor switch sub-circuit is greater than a first on-resistance value of the first transistor switch sub-circuit. Specifically, when the microcontroller turns on the first transistor switch sub-circuit, the transistor switch assembly is turned on; when the microcontroller turns on the second transistor switch sub-circuit, the transistor switch assembly is turned on; when the microcontroller receives a cut-off switch signal, the microcontroller is configured to sequentially turn off the first transistor switch sub-circuit and the second transistor switch sub-circuit to turn off the transistor switch assembly.

2. The stacked transistor switching device according to claim 1, further comprising: A voltage detector, electrically connected to the transistor switching assembly, the microcontroller, and the transistor switching circuit. in, The voltage detector is configured to detect a first voltage at a connection point between the transistor switching assembly and the transistor switching circuit and to notify the microcontroller of the first voltage. When the microcontroller receives the cut-off switch signal, if the first voltage is positive, the microcontroller is configured to sequentially cut off the first transistor switch subcircuit and the second transistor switch subcircuit to cut off the transistor switch assembly.

3. The stacked transistor switching device according to claim 2, wherein, When the microcontroller receives the cut-off switch signal, if the first voltage is negative, the microcontroller is configured to enter a rectification mode; in the rectification mode, when the first voltage changes from positive to negative, the microcontroller is configured to sequentially turn on the second transistor switch sub-circuit and the first transistor switch sub-circuit. In the rectification mode, as the first voltage changes from negative to zero, the microcontroller is configured to sequentially disconnect the first transistor switching subcircuit and the second transistor switching subcircuit to disconnect the transistor switching assembly.

4. The stacked transistor switching device according to claim 3, wherein, The transistor switching circuit further includes: A third transistor switching sub-circuit, electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, the microcontroller, and the voltage detector; and A fourth transistor switching sub-circuit is electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, the third transistor switching sub-circuit, the microcontroller, and the voltage detector. The first, second, third, and fourth transistor switch sub-circuits are connected in parallel. A fourth on-resistance value of the fourth transistor switch sub-circuit is greater than a third on-resistance value of the third transistor switch sub-circuit, and the third on-resistance value of the third transistor switch sub-circuit is greater than the second on-resistance value of the second transistor switch sub-circuit. When the microcontroller turns on the third transistor switch sub-circuit, the transistor switch assembly is turned on. When the microcontroller turns on the fourth transistor switch sub-circuit, the transistor switch assembly is turned on. When the microcontroller receives a switching signal, the microcontroller is configured to sequentially turn on the fourth, third, second, and first transistor switch sub-circuits.

5. The stacked transistor switching device according to claim 4, wherein, When the microcontroller receives the cut-off switch signal, if the first voltage is positive, the microcontroller is configured to sequentially cut off the first transistor switch sub-circuit, the second transistor switch sub-circuit, the third transistor switch sub-circuit, and the fourth transistor switch sub-circuit to cut off the transistor switch assembly.

6. The stacked transistor switching device according to claim 5, wherein, In the rectification mode, when the first voltage changes from positive to negative, the microcontroller is configured to sequentially turn on the fourth transistor switch sub-circuit, the third transistor switch sub-circuit, the second transistor switch sub-circuit, and the first transistor switch sub-circuit; in the rectification mode, during the process of the first voltage changing from negative to zero, the microcontroller is configured to sequentially turn off the first transistor switch sub-circuit, the second transistor switch sub-circuit, the third transistor switch sub-circuit, and the fourth transistor switch sub-circuit to disconnect the transistor switching assembly.

7. The stacked transistor switching device according to claim 6, wherein, The first transistor switching sub-circuit includes: A first metal-oxide-semiconductor field-effect transistor is electrically connected to the transistor switching assembly, the second transistor switching sub-circuit, the third transistor switching sub-circuit, the fourth transistor switching sub-circuit, the microcontroller, and the voltage detector.

8. The stacked transistor switching device according to claim 7, wherein, The second transistor switching sub-circuit includes: A second metal-oxide-semiconductor field-effect transistor (MOSFET), electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the third transistor switching sub-circuit, the fourth transistor switching sub-circuit, the microcontroller, and the voltage detector; and A second resistor, which is electrically connected to the second metal-oxide-semiconductor field-effect transistor, The third transistor switching sub-circuit includes: A third metal-oxide-semiconductor field-effect transistor (MOSFET), the third MOSFET being electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, the fourth transistor switching sub-circuit, the microcontroller, and the voltage detector; and A third resistor, which is electrically connected to the third metal-oxide-semiconductor field-effect transistor, The fourth transistor switching sub-circuit includes: A fourth metal-oxide-semiconductor field-effect transistor (MOSFET), the fourth MOSFET being electrically connected to the transistor switching assembly, the first transistor switching sub-circuit, the second transistor switching sub-circuit, the third transistor switching circuit, the microcontroller, and the voltage detector; and A fourth resistor, which is electrically connected to the fourth metal-oxide-semiconductor field-effect transistor, Wherein, the fourth resistance value of the fourth resistor is greater than the third resistance value of the third resistor, and the third resistance value of the third resistor is greater than the second resistance value of the second resistor.

9. The stacked transistor switching device according to claim 8, wherein, The first transistor switching sub-circuit further includes: A first resistor, which is electrically connected to the first metal-oxide-semiconductor field-effect transistor. Wherein, the second resistance value of the second resistor is greater than the first resistance value of the first resistor.

10. The stacked transistor switching device according to claim 9, wherein, The transistor switching component is a gallium nitride field-effect transistor or a silicon carbide field-effect transistor.

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