Common-source configuration of two transistors

Abstract

The invention relates to a common-source configuration of two transistors (T1, T2), comprising - two control circuits (31, 32) for controlling one of the transistors (T1, T2) each, in order to control a load current through the common-source configuration, - a main current path (10) of the load current, and - a side path (12) of the load current which runs parallel to a section of the main current path (10), wherein one or more control resistors (R1, R2, R12) are arranged in at least one of the control circuits (31, 32), characterized by that at least one of the said control resistors is arranged in the bypass path (12).

Description

Technical field

[0001] The present invention relates to a common-source configuration of two transistors. Technical background

[0002] MOSFETs are known to have, in addition to the drain pin, the source pin and the gate pin, another pin, the so-called "Kelvin pin", see Fig. 1 and Fig.9. This fourth pin allows the gate control circuit to bypass the inductance of the source pin, thus decoupling the gate drive (i.e., the gate control circuit) from the load circuit. This enables an increase in switching speed and a decrease in the required switching energy, resulting in a significant improvement in switching performance. Because the additional Kelvin pin offers many advantages, semiconductor device manufacturers are increasingly equipping MOSFETs with a Kelvin pin and are sometimes no longer offering MOSFETs with only three pins for drain, source, and gate in the standard TO-247 through-hole package, as shown in [reference to TO-247]. Fig.Figure 10 shows more details. Since both the Kelvin pin and the source pin are connected to the transistor's source terminal on the bare die inside the transistor, the Kelvin pin can also be referred to as the Kelvin source terminal or pin, or as the auxiliary source terminal or pin, and the source pin as the power source terminal or pin, for better differentiation. The term "power source terminal" or "power source connection" is used because the load current flows through this terminal, whereas the significantly smaller gate control current flows through the Kelvin source terminal.

[0003] A description of this topic can be found in the journal article "Fully Exploiting the Potential of SiC: SMD MOSFETs with Kelvin Source Pin" in the journal "emobility tec", issue 01 / 2019, authors: Christian Felgemacher, Felipe Filsecker, Farhan Beg, Aly Mashaly, Seiya Kitagawa, pages 14-17, Hüthig Medien GmbH, Heidelberg, Germany, 2019, https: / / www.rohm.de / documents / 4392907 / 6355683 / emobilitytec_0119_080319_Coverstory.pdf / ed87c1ee-02e2-a6ce-5f27-6785fd8405b5?t=1586410136257 (accessed online on March 13, 2024).

[0004] Not only MOSFETs, but also other types of transistors can have such a fourth pin. For example, shows Fig. 12 a 4-pin IGBT with a diode connected in parallel, opposite one in Fig. Figure 11 shows a 3-pin IGBT with a diode connected in parallel. In an IGBT, the fourth pin is called the Kelvin emitter.

[0005] Further information on this matter can also be found in the publication “TRENCHSTOP™ 5 IGBT in a Kelvin Emitter Configuration. Performance Comparison and Design Guidelines”, Application Note, Revision 1.0, dated 2014-10-16, 12 pages, Infineon Technologies AG, Munich, Germany, 2014, https: / / www.infineon.com / dgdl / Infineon-TRENCHSTOP5_in_TO-247-4pin-ApplicationNotes-v01_00-EN.pdf?fileld=5546d4624933b875014974f4d97e09ea (accessed online on 13.03.2024).

[0006] In bidirectional switching applications (AC switching), where it is necessary to switch both positive and negative currents or voltages, the common-source or common-emitter configuration (also known as a common-source or common-emitter circuit) is one of the most widely used circuit configurations; it is also referred to as a "back-to-back" configuration or circuit (AC = Alternating Current). An embodiment of such a common-source configuration is described in EP 1 271 743 A2 (Siemens AG) dated January 2, 2003. Among other advantages, the common-source or common-emitter configuration requires only a single control signal for both transistors, meaning that a single-channel gate driver is sufficient to control the bidirectional semiconductor switch.

[0007] To utilize the advantages of the Kelvin connection in a common-source or common-emitter configuration, where two transistors are connected back-to-back, the Kelvin source or Kelvin emitter terminals of the two transistors must be connected together; they then form the reference potential of the gate driver. A standard gate driver circuit includes a gate driver that provides an output voltage or current, and at least one gate resistor that adjusts the switching behavior of the gate driver. Although this gate resistor is typically located before the gate terminal, as the name suggests, it is sufficient for adjusting the gate drive if it is placed anywhere in the gate control circuit.Since the Kelvin source terminal and the power source terminal are connected inside the transistor, a parallel current path to the load current path is formed via the two Kelvin source terminals, see . Fig. 2; A portion of the main current flows through the bypass path. The distribution of the current between the load current path and the bypass path depends primarily on the internal properties of the semiconductor, such as the electrical resistances in the load current path and the bypass path. However, the bypass path is not designed for high and continuous currents, which is why manufacturers typically advise against using the Kelvin terminals in common-source configurations.

[0008] A bypass current path can occur not only in transistors with Kelvin source or Kelvin emitter terminals in common-source or common-emitter configurations (back-to-back), but generally in all common-source or common-emitter configurations. In a common-source or common-emitter configuration, the gate control circuit is always routed via the source or emitter terminal. Depending on the type of connection between the gate control circuit and the source or emitter terminal, a bypass current path can develop in a common-source or common-emitter configuration that is not designed for the load current. Fig. 3, Fig. 4 to Fig. 5. Summary of the invention

[0009] The present invention is based on the objective of providing an improved common-source or common-emitter configuration. For the sake of simplicity, only the term common-source configuration will be used in the following; it comprises a back-to-back circuit of any two transistor types in which the source and emitter terminals of the transistors are electrically connected.

[0010] This problem is solved according to the invention by a common-source configuration with the features specified in claim 1. The common-source configuration is a back-to-back connection of two transistors; in other words, a bidirectional semiconductor switch consisting of two transistors whose source and emitter terminals are electrically connected. The common-source configuration has two control circuits for controlling one of the transistors each; that is, a first of the two control circuits is configured to control a first of the two transistors, and a second of the two control circuits is configured to control a second of the two transistors. The transistors are controlled to control a load current through the common-source configuration. The common-source configuration according to the invention is hereinafter also referred to as a bidirectional semiconductor switch or simply as a switch.

[0011] The common-source configuration of the two transistors has a main current path for the load current. It also has a secondary current path for the load current, which runs parallel to a section of the main current path. The secondary current path is formed by the connection of the two control circuits. At least one of the control circuits contains one or more control resistors. At least one of these control resistors is located in the secondary current path. Therefore, this at least one control resistor is located in a section of the secondary current path that also forms a section of one of the control circuits.

[0012] The invention is based on the idea that a load current via the bypass path is undesirable, as the bypass path is not designed for the load current and can also form an undesirable resonant circuit: A major problem is the oscillatory behavior of these two parallel current paths, the main current path and the bypass path. The bypass path is generally longer and thinner and therefore has a higher parasitic inductance. Combined with the gate capacitance in the control circuit, this often leads to an undesirable resonant circuit. Therefore, according to the invention, at least one control resistor is arranged in the bypass path: since the connection pins themselves are designed with the lowest possible resistance due to their internal construction (e.g.,Since the values ​​are < 1 mOhm) and the control resistors, which are also called gate resistors, are usually in the single to maximum double digit ohm range, only a relatively small, preferably negligible part of the load current flows via the bypass path, while the vast majority of the load current flows via the main current path designed for the load current.

[0013] The bidirectional semiconductor switch according to the invention is suitable for applications in which electric current flows in both directions; it can therefore be used in AC applications as well as in DC applications with bidirectional current flow (DC = Direct Current). The switch comprises two transistors. These transistors can be bipolar transistors, FETs (e.g., MOSFET, JFET, SIT), IGBTs, GTOs, IGCTs, or other types of transistors. The electrical terminals of the transistors, which can be implemented by pins, wires, or plates protruding from the transistor package, have different designations, which are compared in Table 1 for clarity.Since the present invention can be implemented with different transistor types, without any specific transistor type being preferred, the generalized terms "source terminal", "sink terminal" and "control terminal", which are given in the first column of Table 1, are used in this description of the invention for the electrical terminals of the transistor. Table 1: Designations for the electrical connections of 3-pin transistors transistor Bipolar transistor FET (MOSFET, JFET, SIT, etc.) IGBT Source connection Emitter E Source S Emitter E Sink connection Collector C Drain D Collector C Control connection Base B Gate G Gate G Embodiments of the invention

[0014] Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0015] According to a preferred embodiment of the invention, a first transistor of the two transistors has a first source terminal, a first sink terminal, and a first control terminal. A second transistor of the two transistors has a second source terminal, a second sink terminal, and a second control terminal. The two source terminals are electrically connected. The two sink terminals and the two source terminals are located in the main current path. In a first control circuit of the control circuits, which is configured to control the first transistor, there is a first control unit, a first control series resistor, and the first control terminal. In a second control circuit of the control circuits, which serves to control the second transistor, there is a second control unit, a second control series resistor, and the second control terminal.Parallel to a section of the main current path runs the secondary current path, one half of which is formed by a section of the first control circuit and the other half by a section of the second control circuit. A key advantage is that the common-source configuration uses two 3-pin transistors.

[0016] According to a preferred embodiment of the invention, the first control unit and the second control unit are identical. An advantage of this is that the control of the two transistors in the common-source configuration is achieved with only a single control unit, e.g., a single-channel gate driver.

[0017] According to a preferred embodiment of the invention, the two transistors are each configured as a 4-pin transistor and each has a control terminal, a sink terminal, and two source terminals, wherein a first of the source terminals is referred to as the power source terminal and a second of the source terminals as the Kelvin source terminal. The bypass path is formed by the two interconnected Kelvin source terminals.

[0018] The power source terminal and the Kelvin source terminal are two transistor terminals that are both electrically connected at a junction point to the transistor's internal source terminal (= emitter (bipolar transistor), = source (MOSFET), = emitter (IGBT)). This means that even in transistors with four externally accessible terminals, current or voltage control is achieved using three internal terminals, but the transistor's internal source terminal branches out into two terminals along its current path to the outside: the power source terminal and the Kelvin source terminal. The junction point is always located on the bare die of the transistor; otherwise, it would be technically impossible.

[0019] Since the present invention can be implemented with different types of 4-pin transistors without any specific transistor type being preferred, in this description of the invention the generalized designations “power source terminal”, “Kelvin source terminal”, “sink terminal” and “control terminal”, which are given in the first column of Table 2, are used for the four electrical terminals of the 4-pin transistors used according to the invention. Table 2: Designations for the electrical connections of 4-pin transistors transistor Bipolar transistor FET (MOSFET, JFET, SIT, etc.) IGBT Power source connection Power emitter E Power Source S Power emitter E Kelvin source connection / Kelvin connection Kelvin emitter E Kelvin-Source S Kelvin emitter E Sink connection Collector C Drain D Collector C Control connection Base B Gate G Gate G

[0020] According to a preferred embodiment of the invention, the Kelvin source terminals of the two 4-pin transistors are electrically connected to each other. The two 4-pin transistors are thus interconnected in a manner commonly referred to as a common-source configuration.

[0021] According to a preferred embodiment of the invention, at least one control resistor is arranged in the electrical connection of the Kelvin source terminals. In the prior art, i.e., in a conventional common-source configuration, a typical ("standard") control terminal circuit (often referred to as a "gate circuit") essentially comprises a series connection of a control terminal driver (= voltage source), a control resistor (also referred to as a "control terminal resistor" or "gate resistor"), and the semiconductor control contact "control terminal." The control resistor allows the way in which the semiconductor control contact "control terminal" is driven by the control terminal driver to be optimized.

[0022] According to a preferred embodiment of the invention, these control resistors are removed from the control terminal circuitry, where they are located in a conventional common-source configuration, and instead moved to the electrical connection of the Kelvin source terminals. This relocation of the control resistors from the control terminals to the Kelvin source terminals does not mathematically change the voltage relationships. Only the reference point (GND) of the control terminal driver is now no longer at the common source potential, but at the virtual GND potential after the control resistors, which, due to their relocation, could now also be called source terminal resistors.

[0023] The preferred embodiment of the invention is based on the finding that a shift of the control resistors from the control terminals to the Kelvin source terminals does not change the voltage conditions, but causes the load current in the main current path to increase and in the parallel secondary current path to decrease.

[0024] Considering the bypass path through the Kelvin source terminals, which runs parallel to the main current path, the so-called "Kelvin path," it is observed that, according to a preferred embodiment of the invention, the two control resistors are located in this bypass path. This results in a significantly higher total resistance in the Kelvin path compared to the electrical resistance in the current path through the power source terminals, the so-called "main current path," since the terminals themselves—both the Kelvin source terminals and the power source terminals—are designed with relatively low resistance due to their internal construction (e.g., with resistance values ​​< 1 milliohm). The Kelvin source terminals have significantly thinner bond wires compared to the bond wires of the power source terminals. Therefore, they are not designed with the lowest possible resistance, but rather with the lowest resistance necessary.The control resistors typically have resistance values ​​in the single-digit to double-digit ohm range. For example, assuming that the Kelvin source terminal and the power source terminal of a transistor each have a resistance of 1 milliohm, and the control resistor of a transistor has a resistance of 1 ohm, then with two resistors connected in series, the resistance in the parallel current path ("Kelvin path") is approximately 2000 times higher or more than in the main current path. Therefore, at most, only one two-thousandth of the load current flows through the parallel current path. Thus, no significant portion of the load current flows through the Kelvin source terminals, and therefore there is no risk of overloading them, although the advantages of the Kelvin source terminals regarding switching behavior are retained.

[0025] A significant advantage of the preferred embodiment of the invention is therefore that the advantages of Kelvin connections can also be used for AC semiconductor switches and bidirectional DC semiconductor switches in common-source configuration with Kelvin connections, without having to accept an overload of the semiconductor: The load current via the secondary current path parallel to the main current path through the two Kelvin source connections, the so-called “Kelvin path”, is significantly reduced.

[0026] According to a preferred embodiment of the invention, the electrical resistance in the bypass path is at least ten times greater than the electrical resistance in the main current path due to the at least one control resistor arranged in the bypass path. An advantage of this is that the load current through the bypass path, which is parallel to the main current path, is significantly reduced compared to the load current through the main current path.

[0027] According to a preferred embodiment of the invention, the electrical resistance in the electrical connection of the Kelvin source terminals is at least ten times greater than the electrical resistance in the electrical connection of the power source terminals. An advantage of this is that the load current through the current path parallel to the main current path via the two Kelvin source terminals ("Kelvin path") is significantly reduced compared to the load current through the main current path.

[0028] According to a preferred embodiment of the invention, the electrical resistance in the bypass path is at least a factor of one thousand greater than the electrical resistance in the main current path due to the at least one control resistor arranged in the bypass path. An advantage of this is that the load current through the bypass path, which is parallel to the main current path, becomes negligibly small compared to the load current through the main current path.

[0029] According to a preferred embodiment of the invention, at least one of the transistors is a MOSFET, an IGBT, or a bipolar transistor. An advantage of this is that commercially available and therefore inexpensive transistors can be used.

[0030] According to a preferred embodiment of the invention, the electrically connected control terminals are connected to a control terminal driver. An advantage of this is that a single-channel gate driver is sufficient for controlling the bidirectional semiconductor switch.

[0031] According to a preferred embodiment of the invention, a common control terminal driver is arranged in both control circuits; that is, the two control circuits share the same control terminal driver (= gate driver). An advantage of this is that a single-channel gate driver is sufficient for controlling the bidirectional semiconductor switch, which is more cost-effective than a dual-channel gate driver. Exemplary embodiments of the drawing

[0032] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more easily understood through the following description of exemplary embodiments, which will be explained in more detail with reference to the drawings. The drawings are schematic and not to scale. Fig. 1 a known 4-pin transistor; Fig. 2 a known common-source configuration with two 4-pin transistors and a gate series resistor in each of the two gate control circuits; Fig. 3 a known common-source configuration with two 4-pin transistors and a common gate series resistor for both gate control circuits; Fig. 4 a well-known “simple” common-source configuration with two 3-pin transistors; Fig.5 a known “improved” common-source configuration with two 3-pin transistors and a gate series resistor in each of the two gate control circuits; Fig. 6 the well-known “improved” common-source configuration of Fig. 5 with a common gate series resistor for both gate control circuits; Fig. 7 a common-source configuration according to the invention with two 4-pin transistors; Fig. 8 a common-source configuration according to the invention with two 3-pin transistors; Fig. 9 a MOSFET in the TO-247-4 package; Fig. 10 a MOSFET in the TO-247-3 package; Fig. 11 a 3-pin IGBT with diode; and Fig. 12 a 4-pin IGBT with diode. Detailed description of the exemplary implementations

[0033] Fig.Figure 1 shows a conventional 4-pin transistor T, i.e., a transistor with a Kelvin source terminal K. The transistor shown is a MOSFET. Besides the Kelvin source terminal K, the transistor T naturally has a drain terminal D, a source terminal S, and a gate terminal G. Each of the four transistor terminals D, G, K, S has a non-zero parasitic inductance L: in the Fig.In Figure 1, the inductances of terminals D, G, K, and S are symbolized by the electrical symbol for inductance (“conductor loops”) and designated with the reference symbols Lx, where x is replaced by one of the reference symbols D, G, K, or S of the terminals. The Kelvin source terminal K and the power source terminal S are electrically connected to the transistor's internal source terminal S' at a junction point P. This means that even in transistors with four externally accessible terminals, the current or voltage is controlled using only three internal terminals. However, the internal source terminal S' of transistor T branches out on its current path to terminals K and S into two terminals: the power source terminal S and the Kelvin source terminal K. The MOSFET transistor T inherently incorporates a body diode.

[0034] Fig.Figure 2 shows a conventional bidirectional semiconductor switch in a common-source configuration, with two 4-pin transistors, here MOSFETs, and a gate series resistor in each of the two gate control circuits. The bidirectional semiconductor switch has two 4-pin transistors T1 and T2, a first 4-pin transistor T1 and a second 4-pin transistor T2. Each transistor has a control terminal G1 and G2, a sink terminal D1 and D2, a power source terminal S1 and S2, and a Kelvin source terminal K1 and K2. The control terminals G1 and G2 of the two transistors T1 and T2 are electrically connected at a control terminal contact point GD. The power source terminals S1 and S2 of the two transistors T1 and T2 are electrically connected at a power source terminal contact point 8. And in this process, the Kelvin source connections K1, K2 of the two transistors T1, T2 are electrically connected in a Kelvin source connection contact point 6.The Kelvin source terminal K1 and the power source terminal S1 of the first transistor T1 are electrically connected at a junction point P1 of the first transistor T1 to an internal source terminal S'1 of the first transistor T1. The Kelvin source terminal K2 and the power source terminal S2 of the second transistor T2 are electrically connected at a junction point P2 of the second transistor T2 to an internal source terminal S'2 of the second transistor T2.

[0035] The electrically interconnected control terminals G1 and G2 of the two transistors T1 and T2 are electrically connected to a control terminal driver 4 (voltage source) at the control terminal contact point GD. To utilize the advantages of the Kelvin source terminals K1 and K2, these two Kelvin source terminals are connected at the Kelvin source terminal contact point 6 and form the reference potential of the control terminal driver 4, which provides the output voltage and current. Between the control terminal contact point GD and the transistors T1 and T2, the control terminals G1 and G2 each have a control resistor R1 and R2, respectively, which allows the switching behavior to be adjusted.

[0036] The control terminal driver 4 is also electrically connected at the Kelvin source terminal contact point 6 to the electrically interconnected Kelvin source terminals K1, K2 of the two transistors T1, T2. This results in two control circuits 31, 32 with the control terminal driver 4 as a common voltage source: a first control circuit 31 for controlling the first transistor T1 and a second control circuit 32 for controlling the second transistor T2.

[0037] The diodes required for a bidirectional switch, connected antiparallel to transistors T1 and T2, are intrinsically present in the MOSFET. Only in the case of the IGBT must these diodes be implemented using external components, since an IGBT, due to its termination P-channel layer, does not inherently possess this diode; this is discussed in more detail below. Fig. 11 and Fig. 12 referred.

[0038] The bidirectional semiconductor switch conducts a load current between the two sink terminals D1, D2 on two parallel current paths: Firstly, on a main current path 10, which includes the power source terminals S1, S2 connected to each other at the power source terminal contact point 8. Secondly, on a secondary current path = Kelvin path 12, which includes the Kelvin source terminals K1, K2 connected to each other at the Kelvin source terminal contact point 6.

[0039] The distribution of the load current depends primarily on the internal properties (e.g., resistances) of the bidirectional semiconductor switch. However, Kelvin path 12 is not designed for high and continuous currents, which is why manufacturers of 4-pin transistors typically advise against using the Kelvin source terminals K1 and K2 of the two transistors T1 and T2 in a common-source configuration. Technically, it is possible to omit the Kelvin source terminals K1 and K2, but this also negates the positive effects that can be achieved by using them. The bigger problem with the bypass path (Kelvin path 12), however, is that it can form a noisy resonant circuit.

[0040] Fig. 3 shows, analogous to Fig. 2, an alternative known common-source configuration with two 4-pin transistors. In contrast to the one in Fig.The common-source configuration shown in Figure 2, in which each of the control circuits 31, 32 has its own control series resistor R1, R2, exhibits the following characteristics: Fig. The common-source configuration shown in Figure 3 uses a common control resistor R12 for both control circuits 31 and 32. Apart from that, the following are shown in Figure 3: Fig. 2 and Fig. The 3 Common Source configurations shown are identical.

[0041] Fig.Figure 4 shows a familiar "simple" common-source configuration with two 3-pin transistors T1 and T2. These are MOSFETs: the explicitly drawn diodes 21 and 22 symbolize the body diodes intrinsically present in the MOSFET. The two source terminals S1 and S2 of transistors T1 and T2 are electrically connected at the source terminal contact point 8. The two gate terminals G1 and G2 of transistors T1 and T2 are each arranged in a control circuit 31 and 32, each with a separate control resistor R1 and R2. The two control circuits 31 and 32 are supplied with voltage by a common control terminal driver 4. The control circuits 31, 32 each run from the control terminal driver 4 via the source terminal contact point 8 to the two source terminals S1, S2 and from there via the gate terminals G1, G2 back to the control terminal driver 4.A significant disadvantage of this "simple" circuit is that the path lengths w of the control circuits 31, 32, which coincide with the main current path 10, are relatively long: since there is a significant inductance on these paths w, the switching behavior of the control circuits 31, 32 is considerably degraded. This is precisely the motivation for separating the main current path 10 from the control circuits 31, 32 as early as possible, as shown in [reference]. Fig. Figure 5 is shown. And that is precisely one motivation for equipping transistors with a Kelvin source.

[0042] Fig. Figure 5 shows a known “improved” common-source configuration with two 3-pin transistors and a control resistor R1, R2 in each of the two control circuits 31, 32. The improvement of the in Fig. The common-source configuration shown in section 5 is different from the one in [section / document]. Fig.The common-source configuration shown in Figure 4 consists of shortening the path lengths w of the control circuits 31 and 32 that coincide with the main current path 10. This reduces the inductance in the control circuits 31 and 32 and thus improves their switching behavior. The shortening of the path lengths w is achieved by splitting the previously shared section of the control circuits 31 and 32 between the GND (-) of the control terminal driver 4 and the main current path 10 at a junction point 7 into two separate branches of the control circuits 31 and 32, each of which then connects to the main current path 10 at a separation point 9. In this way, a secondary current path 12 of the load current is created by the two separate branches of the control circuits 31 and 32, each extending between the junction point 7 and the separation point 9.

[0043] Fig.Figure 6 shows the well-known "improved" common-source configuration of Fig. 5 with a common control resistor for both control circuits 31, 32. In contrast to the one in Fig. The common-source configuration shown in Figure 5, in which each of the control circuits 31, 32 has its own control series resistor R1, R2, exhibits the following characteristics: Fig. The common-source configuration shown in Figure 6 includes a common control resistor R12 for both control circuits 31 and 32. Apart from that, the following are shown in Figure 6: Fig. 5 and Fig. The 6 common-source configurations shown are identical.

[0044] Fig. Figure 7 shows a bidirectional semiconductor switch according to the invention in a common-source configuration with two 4-pin transistors. It largely corresponds to the one in Fig.The two conventional bidirectional semiconductor switches in common-source configuration shown in Figure 2 are used, with the crucial difference that the control resistors R1, R2 are arranged in the bypass path 12. Therefore, only a relatively small, preferably negligible, portion of the load current flows through the bypass path 12, while the vast majority of the load current flows through the main current path 10, which is designed for the load current. Thus, no significant load current flows through the bypass path (Kelvin path 12), and therefore there is no risk of overloading the Kelvin source terminals K1, K2. Nevertheless, the advantages in switching behavior that can be achieved by using the Kelvin source terminals K1, K2 are retained.

[0045] Fig.Figure 8 shows a common-source configuration according to the invention with two 3-pin transistors. To recognize the essential feature of this common-source configuration according to the invention, it is to be compared with the one shown in Fig. 5 shown known “improved” common-source configurations. The in Fig. The common-source configuration shown in section 8 largely corresponds to the one in Fig. The conventional common-source configuration shown in Figure 5 is used, with the crucial difference that the control resistors R1 and R2 are arranged in the bypass path 12. Therefore, only a relatively small, preferably negligible, portion of the load current flows through the bypass path 12, while the vast majority of the load current flows through the main current path 10, which is designed for the load current.

[0046] Fig.Figure 9 shows a known 4-pin MOSFET in a TO-247-4 package. The 4-pin MOSFET has a Kelvin source pin K, a sink pin D ("Drain"), a power source pin S ("Source"), and a control pin G ("Gate").

[0047] Fig. Figure 10 shows a known 3-pin MOSFET in a TO-247-3 package. The 3-pin MOSFET has a drain terminal D, a source terminal S, and a gate terminal G.

[0048] Fig.Figure 11 shows a circuit diagram of a known 3-pin IGBT with a separate freewheeling diode; while a MOSFET intrinsically has a body diode, an IGBT, which does not have an intrinsic diode, must be equipped with a separate diode if bidirectional operation is required. Such a 3-pin IGBT can be housed in a TO-247-3 package. The 3-pin IGBT has a sink terminal C (“collector”), a source terminal E (“emitter”), and a control terminal G (“gate”).

[0049] Fig. Figure 12 shows a circuit diagram of a known 4-pin IGBT with a separate freewheeling diode. Such a 4-pin IGBT can be housed in a TO-247-4 package. The 4-pin IGBT has a Kelvin source terminal E' (“Kelvin emitter” or “auxiliary emitter”), a power source terminal E (“emitter”), a sink terminal C (“collector”), and a control terminal G (“gate”). Reference symbol list 4 control port drivers 6 Kelvin source connection contact point 7 Branching point from GND 8 Power source connection contact point, source termination contact point 9 Separation point Main current path - Control circuit 10 Main flow path 12 Sidestream path 21 Diode 22 Diode 31 Control circuit 32 Control circuit D sink connection of T D1 sink connection from T1 D2 sink connection from T2 GD control connection contact point G control connection of T GND Ground G1 control connection of T1 G2 control connection of T2 K Kelvin source connection of T K1 Kelvin source connection of T1 K2 Kelvin source connection from T2 LD inductance of D LG Inductance of G LK Inductance of K LS inductance of S P Branching point of T P1 Branching point of T1 P2 Branching point of T2 R1 Control resistor of T1 R2 Control resistor of T2 S Power source connection from T S1 Power source connection of T1 S2 Power Source Connection of T2 S' internal source connection of T S'1 internal source connection of T1 S'2 internal source connection of T2 T Transistor T1 transistor, first, of the bidirectional semiconductor switch T2 transistor, second, of the bidirectional semiconductor switch QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 1 271 743 A2

[0006] Cited non-patent literature

[0000] Issue 01 / 2019, Authors: Christian Felgemacher, Felipe Filsecker, Farhan Beg, Aly Mashaly, Seiya Kitagawa, Pages 14-17, Hüthig Medien GmbH, Heidelberg, Germany, 2019, https: / / www.rohm.de / documents / 4392907 / 6355683 / emobilitytec_0119_080319_Coverstory.pdf / ed87c1ee-02e2-a6ce-5f27-6785fd8405b5?t=1586410136257 (Accessed online on 13.03.2024

[0003] "Performance Comparison and Design Guidelines", Application Note, Revision 1.0, dated 2014-10-16, 12 pages, Infineon Technologies AG, Munich, Germany, 2014, https: / / www.infineon.com / dgdl / Infineon-TRENCHSTOP5_in_TO-247-4pin-ApplicationNotes-v01_00-EN.pdf?fileld=5546d4624933b875014974f4d97e09ea (accessed online on 13.03.2024

[0005]

Claims

[1] Common-source configuration of two transistors (T1, T2), having - two control circuits (31, 32) for controlling one of the transistors (T1, T2) each, in order to control a load current through the common-source configuration, - a main current path (10) of the load current, and - a side path (12) of the load current which runs parallel to a section of the main current path (10), wherein one or more control resistors (R1, R2, R12) are arranged in at least one of the control circuits (31, 32), characterized by , that at least one of the said control resistors is arranged in the bypass path (12). [2] Common-source configuration according to claim 1, wherein - a first transistor (T1) of the two transistors (T1, T2) has a first source terminal (S1), a first sink terminal (D1) and a first control terminal (G1), - a second transistor (T2) which has a second source terminal (S1), a second sink terminal (D1) and a second control terminal (G1) in addition to the two transistors (T1, T2), where the two source connections (S1, S2) are electrically connected, wherein the two sink terminals (D1, D2) and the two source terminals (S1, S2) are located in the main flow path (10), wherein in a first control circuit (31) of the control circuits (31, 32), which serves to control the first transistor (T1), there is a first control unit (4), a first control series resistor (R1) and the first control terminal (G1), wherein in a second control circuit (32) of the control circuits (31, 32), which serves to control the second transistor (T2), there is a second control unit (4), a second control series resistor (R2) and the second control terminal (G2), wherein parallel to a section of the main current path (10) runs the secondary current path (12), one half of which is formed by a section of the first control circuit (31) and the other half of which is formed by a section of the second control circuit (32). [3] Common-source configuration according to claim 2, wherein the first control unit (4) and the second control unit (4) are identical. [4] Common-source configuration according to any of the preceding claims, wherein the two transistors (T1, T2) each have four terminals comprising a control terminal (G1, G2), a sink terminal (D1, D2), a power source terminal (S1, S2) and a Kelvin source terminal (K1, K2), wherein the bypass path (12) is formed by the two interconnected Kelvin source terminals (K1, K2). [5] Common-source configuration according to one of the preceding claims, wherein the electrical resistance in the bypass path (12) is at least ten times greater than the electrical resistance in the main current path (10) due to the at least one control series resistor (R1, R2, R12) arranged in the bypass path (12). [6] Common-source configuration according to claim 5, wherein the electrical resistance in the bypass path (12) is at least a factor of one thousand greater than the electrical resistance in the main current path (10) due to the at least one control series resistor (R1, R2, R12) arranged in the bypass path (12). [7] Common-source configuration according to any of the preceding claims, wherein at least one of the transistors is a MOSFET, an IGBT or a bipolar transistor. [8] Common-source configuration according to one of the preceding claims, wherein a control terminal driver (4) common to the control circuits (31, 32) is arranged in the control circuits (31, 32).

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