Switching circuit arrangement, DC voltage interface and method for operating a switching circuit arrangement

Abstract

Switching circuit arrangement (1000; 2000; 3000; 4000) for providing during an ON state a connection between a first port (1002) for receiving an input voltage (Vin; U(t)) and a second port (1004) and for electrically disconnecting during an OFF state of the first port (1002) from the second port (1004), wherein the switching circuit arrangement comprises the following: a first cascode transistor element (100) having an applicable operating voltage and comprising a first control terminal (102), wherein the first cascode transistor element (100) is connected to the first port (1002) of the switching circuit arrangement; and a second cascode transistor element (200) which also has the applicable operating voltage and includes a second control terminal (202), wherein the second cascode transistor element (200) is connected to the second port (1004) of the switching circuit arrangement; a switching transistor element (300; 350) which also provides the applicable operating voltage and includes a third control terminal (302), wherein the switching transistor element (300; 350) is connected in series between the first (100) and second (200) cascode transistor elements; and a supply signal arrangement (400; 800) connected to the first (102), second (202) and third (302) control terminals and configured to supply a first control voltage (104) to the first control terminal (102), to supply a second control voltage (204) to the second control terminal (202) and to supply a third control voltage (304) to the third control terminal (302); wherein the first cascode transistor element (100) is connected to a first matching circuit arrangement (500), the first matching circuit arrangement (500) is connected between the first control terminal (102) and a reference potential (1006) and is configured to match the first control voltage (104) such that during the ON state the voltage difference between the first control voltage (104) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; wherein the second cascode transistor element (200) is connected to a second matching circuit arrangement (600), wherein the second matching circuit arrangement (600) is connected between the second control terminal (202) and the reference potential (1006) and is configured to adjust the second control voltage (204) such that during the ON state the voltage difference between the second control voltage (204) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; wherein the switching transistor element (300; 350) is connected to a third matching circuit arrangement (700), the third matching circuit arrangement (700) being connected between the third control terminal (302) and the reference potential (1006) and being configured to adjust the third control voltage (304) such that, during the ON state, the voltage difference between the third control voltage (304) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; and where a maximum voltage level (U max ) the input voltage (Vin; U(t)) is higher than the applicable operating voltage.

Description

Technical field

[0001] Embodiments relate to switching circuit arrangements. Further embodiments relate to a DC voltage interface comprising a switching circuit arrangement and a method for operating a switching circuit arrangement. Other embodiments also relate to a medium-voltage input switch with a protected low-voltage transistor. Technical background

[0002] Historically, many applications use a five-volt interface in analog and digital inputs / outputs (I / Os). In this application, this voltage will also be present at the power supply. Devices and circuits use a power supply provided by a switching circuit arrangement for operation.

[0003] US Patent 8,022,745 B1 describes a high-voltage semiconductor switch formed from a chain of cascode circuits connected in series. The switch can be a single-throw configuration coupled between an output and a direct current (DC) reference.

[0004] US Patent 2014 / 0002051 A1 describes a cascode circuit that uses MOS transistors. In one embodiment, an adaptive cascode circuit may include: (i) a main MOS transistor; (ii) n adaptive MOS transistors connected in series with the drain of the main MOS transistor, where n may be an integer greater than one; (iii) a turn-off clamping circuit connected to the gates of the n adaptive MOS transistors. Brief description

[0005] A concept for using switching elements, such as transistors, that span a voltage class below or lower than the voltage to be switched is disclosed. By adjusting the control voltages of transistor elements, the transistor elements can be used to switch voltages higher than their applicable operating voltage.

[0006] Embodiments provide a switching circuit arrangement for maintaining a connection between a first port, configured to receive an input voltage, and a second port during an ON state, and for electrically disconnecting the connection from the second port during an OFF state. The switching circuit arrangement comprises a first cascode transistor element, a second cascode transistor element, and a switching transistor element. The first cascode transistor element, the second cascode transistor element, and the switching transistor element each have an applicable operating voltage and include a control terminal. The first cascode transistor element is connected to the first port of the first switching interface. The second cascode transistor element is connected to the second port of the switching interface. The switching transistor is connected in series between the first and second cascode transistor elements.The switching circuit arrangement comprises a supply signal arrangement connected to the control terminal of the first cascode transistor element, the control terminal of the second cascode transistor element, and the control terminal of the switching transistor element. The supply signal arrangement is configured to provide a first control voltage to the first control terminal of the first cascode transistor element, a second control voltage to the second control terminal of the second cascode transistor element, and a third control voltage to the third control terminal of the switching transistor element. The first cascode transistor element is connected to a first matching circuit arrangement.The first matching circuit is connected between the first control terminal and a reference potential and is configured to adjust the first control voltage so that, during the ON state, the voltage difference between the first control voltage and the input voltage is less than or equal to the applicable operating voltage, which is a voltage above which the transistor element could be damaged during operation. The second cascode transistor element is connected to a second matching circuit. The second matching circuit is connected between the second control terminal and the reference potential and is configured to adjust the second control voltage so that, during the ON state, the voltage difference between the second control voltage and the input voltage is less than or equal to the applicable operating voltage.The switching transistor element is connected to a third matching circuit arrangement. This third matching circuit arrangement is connected between the third control terminal and the reference potential and is configured to adjust the third control voltage so that, during the ON state, the voltage difference between the third control voltage and the input voltage is less than or equal to the applicable operating voltage. The maximum input voltage level is higher than the applicable operating voltage. Matching the control voltage at the first cascode transistor element, the second cascode transistor element, and the switching transistor element allows the voltage-induced workload of the transistor elements to be adjusted to a level at which they remain undamaged, even when a voltage above the applicable operating voltage is being switched.This can make it possible to avoid high-voltage transistors in the switching interface, and / or to use low-voltage transistors, and can therefore allow for reduced complexity.

[0007] Another embodiment provides a DC voltage interface comprising a previously mentioned switching circuit arrangement. Such a DC voltage interface can be of low complexity, which can enable rapid production since a small number of manufacturing steps are required.

[0008] Another embodiment provides a method for operating a switching circuit arrangement that receives an input voltage, wherein the switching circuit arrangement is operated in an ON state and an OFF state. The method comprises providing a connection between a first port and a second port during the ON state and electrically disconnecting the first port from the second port during the OFF state. The switching circuit arrangement comprises a first cascode transistor element having an applicable operating voltage and including a first control terminal, wherein the first cascode transistor element is connected to the first port of the switching circuit arrangement.The switching circuit arrangement further comprises a second cascode transistor element, which also provides the applicable operating voltage and includes a second control terminal, wherein the second cascode transistor element is connected to the second port of the switching circuit arrangement. The switching circuit arrangement further comprises a switching transistor element, which also provides the applicable operating voltage and includes a third control terminal, wherein the switching transistor element is connected in series between the first and second cascode transistor elements. The method comprises supplying a first control voltage to the first control terminal, supplying a second control voltage to the second control terminal, and supplying a third control voltage to the third control terminal.The method further comprises adjusting the first control voltage by means of a first source follower connected to the first cascode transistor element, such that during the ON state the voltage difference between the first control voltage and the input voltage is less than or equal to the applicable operating voltage. The method further comprises adjusting the second control voltage by means of a second source follower connected to the second cascode transistor element, such that during the ON state the voltage difference between the second control voltage and the input voltage is less than or equal to the applicable operating voltage.The method further includes adjusting the third control voltage by means of a third source follower connected to the switching transistor element, such that during the ON state the voltage difference between the third control voltage and the input voltage is less than or equal to the applicable operating voltage. The maximum input voltage level is higher than the recommended operating voltage.

[0009] Further examples provide another method for operating a switching circuit arrangement that receives an input voltage between an ON state and an OFF state. The method includes providing a connection between a first port and a second port during the ON state and electrically disconnecting the first port from the second port during the OFF state. The switching circuit arrangement comprises switching circuit sections arranged in series between a first port and a second port, each switching circuit section comprising a transistor element. A first transistor element is arranged between and connected in series with a second and a third transistor element.The method comprises applying the input voltage to the first port such that the input voltage includes a maximum voltage level higher than any applicable operating voltage of the first, second, and third transistor elements. The method further comprises controlling a control voltage of the first, second, and third transistor elements of the switching circuit arrangement sections such that, during the ON state, the operating voltage of the first, second, and third switching transistor elements between a control terminal and a power terminal of the switching transistor elements is less than or equal to the applicable operating voltage of the first, second, and third switching transistor elements.

[0010] The embodiments are described here with reference to the accompanying drawings. Fig. Figure 1 shows a schematic block diagram of a switching circuit arrangement according to one embodiment; Fig. Figure 2 shows a schematic block diagram of a switching circuit arrangement according to an embodiment in which a supply signal arrangement may include matching circuit arrangements; Fig. Figure 3 shows a schematic block diagram of a switching circuit arrangement according to an embodiment in which the supply signal arrangement may include a current mirror; Fig. Figure 4 shows a schematic block diagram of a switching circuit arrangement according to another embodiment, in which the supply signal arrangement is different from the supply signal arrangement made of Fig. 3 different; Fig. Figure 5a shows a schematic block diagram of the switching circuit arrangement. Fig. 4 in an ON state according to one embodiment; Fig. Figure 5b shows a schematic block diagram of the switching circuit arrangement. Fig. 4 in an OFF state according to one embodiment; and Fig. Figure 6 shows a schematic block diagram of a DC voltage interface according to one embodiment. Detailed description of the embodiments

[0011] Before embodiments are described in detail using the accompanying figures, it must be pointed out that the same or functionally equivalent elements in the figures are given the same reference numerals and that a repeated description for elements that are provided with the same or similar reference numerals is typically omitted.

[0012] Therefore, descriptions provided for elements with the same reference numbers are mutually interchangeable and accurate.

[0013] The embodiments described here can involve high and low voltages. Some embodiments described here may involve switching circuit arrangements for switching voltages in the 5-volt range, while using transistor elements that have a recommended operating voltage in the 2.5-volt range. In connection with these embodiments, 5 volts can be understood as high voltage, while 2.5 volts can be understood as low voltage. In connection with other embodiments described here, any voltage greater than a recommended operating voltage of a transistor element, or any applicable operating voltage applicable to transistor elements, can be understood as high voltage, and any voltage equal to or less than the recommended operating voltage can be understood as low voltage.

[0014] The recommended operating voltage can be a device-dependent voltage or potential between each control terminal, such as a gate or base of a transistor, and another terminal of the transistor, such as a source or drain, collector or emitter. For example, the recommended operating voltage may be specified in a datasheet for the transistor element. The recommended operating voltage can be a voltage applied to the terminals of the transistor element that allows normal operation without damaging the transistor element by overvoltage.

[0015] Transistor elements may be designed to operate at a recommended operating voltage. To allow the transistor elements to operate at a voltage other than the recommended operating voltage, the effective applied voltage may vary within a fault window above and / or below the recommended operating voltage. In particular, transistor elements may be operated at voltage levels higher than the recommended operating voltage, but still low enough not to damage the transistor element, or at least not significantly. That is, the applied operating voltage may vary within a permissible range of the fault window and may be higher or lower than the recommended operating voltage. Accordingly, the applicable operating voltage may be a value within the permissible range, in particular a maximum value within it.Such an applicable voltage level within the permissible range is hereinafter referred to as the applicable operating voltage. The embodiments described here may involve an applicable operating voltage that is greater than the recommended operating voltage within the tolerance range of the permissible range. In other words, the level of the applicable operating voltage may lie within the permissible range of the recommended operating voltage or its maximum value. For example, the recommended operating voltage may be a mean or average value of the voltage range defined by the permissible range. The tolerance range of the applicable operating voltage may, for example, be at most 35% (e.g., between 0% and 35%), at most 25% (e.g., between 5% and 30%), or at most 25% (e.g., between 10% and 25%) of the recommended operating voltage.In particular, the applicable operating voltage may be higher than the recommended operating voltage, so that the applicable operating voltage can exceed the recommended operating voltage by the tolerance range. The applicable operating voltage may even be higher in a currentless or powerless operating mode of the transistor element. Accordingly, the applicable operating voltage can be higher than the recommended operating voltage within the tolerance range.

[0016] Operating a transistor element at the applicable operating voltage can allow repeated switching of the transistor element without significant damage. That is, a small degree of damage may be tolerable. Accordingly, a compromise can be made between tolerable wear and the performance class of the transistor elements used. For example, the number of possible switching cycles or the operating lifetime of the transistor element may be reduced by a maximum of 30%, 20%, or 10% if the transistor element is operated at the applicable operating voltage instead of the recommended operating voltage.

[0017] Transistor elements can be, for example, CMOS transistors, such as n-type or p-type transistors. Other transistor elements can be bipolar transistors. The embodiments described here relate to CMOS transistors, although the embodiments are not limited to them. The functionality of transistor elements can be transferred to transistor elements of other types (for example, bipolar transistors) and / or other conductivity types (such as between n-type and p-type). Accordingly, the voltage between a gate terminal and a source terminal (Vg) is defined below. GSOP The recommended operating voltage described is not limited to a voltage between a gate and a source, but may also apply to other transistor types or terminals.

[0018] Accordingly, the control connections described here can relate to a gate terminal of a MOS transistor element or a base terminal of a bipolar transistor element. A power connection mentioned below can relate to a source or drain terminal of a MOS transistor element, or to a collector or emitter terminal of a bipolar transistor element.

[0019] Fig. Figure 1 shows a schematic block diagram of a switching circuit arrangement 1000. The switching circuit arrangement 1000 comprises a first port 1002 and a second port 1004. Both the first port 1002 and the second port 1004 can be used as an input port or as an output port. That is, an input side and an output side of the switching circuit arrangement 1000 can be switched, meaning a full voltage swing between the reference potential, such as 0 volts, and a maximum input voltage can occur on both sides and at both ports 1002 and 1004. The switching circuit arrangement 1000 can be switched or controlled to include an ON state or an OFF state. Accordingly, the switching circuit arrangement 1000 can be switched between the ON state and the OFF state.During the ON state, the switching circuit arrangement 1000 can provide an electrical connection between the first port 1002 and the second port 1004. This electrical connection can be understood as providing a low-impedance or low-resistance path between ports 1002 and 1004. During the OFF state, the switching circuit arrangement 1000 can electrically disconnect the first port 1002 from the second port 1004. Such disconnection can be understood as providing a high-impedance or high-resistance path between ports 1002 and 1004. Alternatively, the electrical disconnection can include a mechanical disconnection, although such a mechanical disconnection is not necessary.Accordingly, the electrical isolation between ports 1002 and 1004 can be understood as increasing a resistance between the two ports 1002 and 1004, so that a flow of electric current between the two ports 1002 and 1004 is reduced or prevented.

[0020] The switching circuit arrangement 1000 can include a cascode transistor element 100 connected to port 1002. The cascode transistor element 100 can include a control terminal 102. The control terminal 102 can be configured to receive a control voltage to control a state or condition of the cascode transistor element 100. The cascode transistor element 100 can be, for example, of the "on" or "off" type. The cascode transistor element 100 can, for example, be an n-type metal-oxide-semiconductor (MOS) transistor element with an off-state configuration. Based on a control voltage 104 applied to the control terminal 102, such as a gate terminal, the conductivity between a source terminal and a drain terminal of the cascode transistor element 100 can be controlled or influenced.

[0021] The switching circuit arrangement 1000 can include a further cascode transistor element 200 connected to port 1004. The transistor element 200 can include a control terminal 202 for receiving a control voltage 204, as described in connection with the control terminal 102 and the control voltage 104 with reference to the cascode transistor element 100.

[0022] The switching interface 1000 can include a switching transistor element 300, which includes a control terminal 302 for receiving a control voltage 304, as described in connection with the cascode transistor element 100. The switching transistor element 300 can be connected between the cascode transistor elements 100 and 200; for example, the switching transistor element 300 can be connected in series between the cascode transistor elements 100 and 200. For example, a source terminal of the cascode transistor element 100 can be connected to a drain terminal of the switching transistor element 300. Furthermore, a source terminal of the switching transistor element 300 can be connected to a drain terminal of the cascode transistor element 200.

[0023] In the ON state of the switching circuit arrangement 1000, the cascode transistor elements 100 and 200 and the switching transistor element 300 can include a low-impedance or low-resistance path between the source and drain terminals. In the OFF state of the switching circuit arrangement 1000, one or more, preferably all, of the transistor elements 100, 200, and 300 can include a high-resistance path between the source and drain terminals, thus providing electrical isolation between ports 1002 and 1004.

[0024] Each of the transistor elements 100, 200 and 300 can have a recommended operating voltage (gate-source operation - VGSOP) V GSOPThis includes a voltage that may be device-dependent, i.e., it may depend on the specific transistor element. Each of the transistor elements 100, 200, and 300 can be operated with an applicable operating voltage, which may also be device-dependent. Accordingly, a level or value of the recommended operating voltage V may be specified. GSOP and / or the applicable operating voltage depend on parameters of transistor element 100, 200, 300, respectively. Transistor elements 100, 200, and 300 may have the same recommended operating voltage; that is, the recommended operating voltage and / or the applicable operating voltage may be substantially the same. "Substantially the same" may be understood, for example, as being within a tolerance range of no more than 15%, 10%, or 5% of any of the recommended operating voltage values ​​of transistor elements 100, 200, or 300.

[0025] The switching circuit arrangement 1000 can include a supply signal arrangement 400. The supply signal arrangement 400 can be connected to the control terminals 102, 202, and 302. The supply signal arrangement 400 can be configured to provide the control voltages 104, 204, and 304. As will be described in more detail later, the control voltages 104 and 204 can be equal or identical according to some embodiments, which may allow the supply signal arrangement 400 to have a first port connected to the cascode transistor elements 100 and 200 and a second port connected to the switching transistor element 300. Alternatively, the supply signal arrangement can be configured to provide each of the control voltages 104, 204, and 304 separately.The supply signal arrangement 400 can also be called a charge pump (CP: Charge Pump) and can be configured to output a higher voltage compared to the input voltage U(t), thus enabling the switching of transistor elements 100, 200 and 300 at any time.

[0026] The switching transistor element 300 can be referred to as the primary switching component of the switching circuit arrangement 1000, or as the real switch. The cascode transistor elements 100 and 200 can be referred to as protection transistors, forming a cascode with the switching transistor 300. In simplified terms, the cascode transistor elements 100 and 200 can be arranged to protect the switching transistor element 300. Protection can be understood in the context of a possible overvoltage of the switching circuit arrangement 1000, which is configured to receive an input voltage U(t) at port 1002. The input voltage U(t) can vary over time and can have a maximum value Umax. max include the maximum value U max may include a value that is higher than the recommended operating voltage V GSOPThe transistor element count is 100, 200, and / or 300 higher and can be higher than the applicable operating voltage. According to the understanding of the embodiments described here, the maximum voltage U can be max compared to V GSOP , which is a low voltage, can be a high voltage. The maximum voltage level U max The input voltage U(t) can be defined as the maximum voltage level U max to be understood as being at least 50%, 75% or 100% higher than the recommended operating voltage V GSOP Accordingly, the cascode transistor elements 100 and / or 200 and / or the switching transistor element 300 may be damaged upon initial inspection if the maximum input voltage U max is created. However, this is not the case, as described below.

[0027] A first matching circuit arrangement 500 is connected between the control terminal 102 and a reference potential 1006 of the switching circuit arrangement. The reference potential 1006 can be, for example, 0 volts, ground (GND), or any other reference value. The matching circuit arrangement 500 can be configured to adjust the control voltage 104 provided by the supply signal arrangement 400 so that, during the ON state, the voltage difference between the control voltage 104 and the input voltage U(t) is less than or equal to the applicable operating voltage. For example, the control voltage 104 is provided by the supply signal arrangement 400 such that it includes a voltage level that is at least the input voltage U(t) plus an offset voltage of the cascode transistor element 100.The offset voltage can include a threshold voltage that allows the cascode transistor element 100 to operate in a conductive mode, e.g., if the cascode transistor element is a self-blocking n-type CMOS transistor. Alternatively, the offset voltage can include a value corresponding to the recommended operating voltage V. GSOP This corresponds to the first point in time when the input voltage U(t) can be close to or at the maximum value U. max include and the control voltage 104 can include a level higher than the maximum input voltage U max If the input voltage U(t) is reduced at a second time, the voltage difference between the control voltage 104 and the input voltage U(t) at the constant control voltage 104 would increase, which could lead to a voltage difference greater than the recommended operating voltage V. GSOPand / or the applicable operating voltage, which could lead to damage to the cascode transistor element 100. The matching circuit arrangement 500 can be configured to adjust the control voltage 104 so that the voltage difference between the control voltage 104 and the input voltage U(t) is kept below or equal to the applicable operating voltage in the ON state. The matching circuit arrangement 500 can be configured to adjust or control the control voltage 104 so that the control voltage 104 remains below or equal to the applicable operating voltage in the OFF state. Accordingly, damage to the cascode transistor element 100 can be prevented. The matching circuit arrangement 500 and the cascode transistor element 100 can form a first switching circuit section.

[0028] The switching circuit arrangement 1000 comprises an matching circuit arrangement 600, which is connected between the control terminal 202 of the cascode transistor element 200 and the reference potential 1006. The matching circuit arrangement 600 can be configured to adjust the control voltage 204 so that, during the ON state, the voltage difference between the control voltage 204 and the input voltage U(t) is less than or equal to the applicable operating voltage. The matching circuit arrangement 600 can be configured to adjust or control the control voltage 204 so that, in the OFF state, the control voltage 204 remains less than or equal to the applicable operating voltage. The matching circuit arrangement 600 and the cascode transistor element 200 can form a second switching circuit arrangement section.

[0029] The switching circuit arrangement 1000 further comprises an matching circuit arrangement 700, which is connected between the control terminal 302 and the reference potential 1006. The matching circuit arrangement 700 can be configured to adjust the control voltage 304 so that, during the ON state, the voltage difference between the control voltage 304 and the input voltage U(t) is less than or equal to the applicable operating voltage. The matching circuit arrangement 700 can be configured to adjust or control the control voltage 304 so that, in the OFF state, the control voltage 304 remains below or equal to the applicable operating voltage. The matching circuit arrangement 700 and the switching transistor element 300 can form a third switching circuit arrangement section.

[0030] The source and / or drain terminals of each of the transistor elements 100, 200, and 300 can carry the input voltage U(t) when the transistor elements 100, 200, and 300 are in a conductive operating mode. Accordingly, in the ON state, the input voltage U(t) can be present at the source and drain terminals of the transistor elements 100, 200, and 300. This allows the matching circuit arrangements 500, 600, and 700 to be implemented in the same or a comparable manner, so that explanations given with reference to matching circuit arrangement 500 can also apply to matching circuit arrangements 600 and / or 700. In other words, the matching circuit arrangements 500, 600, and 700 can be configured to define the gate voltages under all conditions, thus enabling further protection of the transistor elements.

[0031] Although the maximum voltage level U maxthe input voltage U(t) is higher than the recommended operating voltage V GSOP and is higher than the applicable operating voltage, the control voltages 104, 204 and 304 can accordingly be adjusted to a level below a critical level, so that damage to the transistor elements 100, 200 and 300 is prevented.

[0032] The development of CMOS (Complementary Metal-Oxide-Semiconductor) technologies is moving towards smaller transistor sizes defined by digital performance and area. Digital core transistors with thinner gate oxides and a voltage rating below one volt can be used for this purpose. In CMOS technologies with a minimum length greater than 0.5 micrometers, the same transistor elements have been used for both the analog interface and the digital logic. This can be difficult or even impossible to implement with submicrometer CMOS technologies. Here, a dedicated 5-volt (VDD-HV) transistor element is typically implemented to support "high-voltage" applications. This can increase process complexity and cost. Along with the digital core transistor, each technology can typically provide a dual-gate oxide transistor.A double-gate oxide transistor can refer to an implementation of the transistor with two gate oxides stacked on top of each other, i.e., a double layer of gate oxides. This double-gate oxide transistor can have a voltage rating in the range of 2.5 volts (VDDHV / 2). An analog device described here can be understood as having both an indeterminate or uncertain voltage value on the input and output sides, and / or as having a voltage that can vary continuously. In the case of digital drivers, at least one side can be discrete, i.e., exhibit a discrete voltage value.

[0033] A method for operating a switching circuit arrangement, such as the switching circuit arrangement 1000, may include a step of providing a connection between the first port 1002 and a second port 1004 during the ON state and of electrically disconnecting the first port 1002 from the second port 1004 during the OFF state. The switching circuit arrangement 1000 may include the first cascode transistor element 100, which provides the recommended operating voltage V GSOP The switching circuit arrangement 1000 comprises a second cascode transistor element 200, which also provides the applicable operating voltage and includes the first control terminal 102, wherein the first cascode transistor element 100 is connected to the first port 1002. The switching circuit arrangement 1000 further comprises a second cascode transistor element 200, which also provides the recommended operating voltage V GSOPThe switching circuit arrangement 1000 comprises a switching transistor element 300, which also provides the applicable operating voltage and includes a second control terminal 202, wherein the second cascode transistor element 200 is connected to the second port 1004. The switching circuit arrangement 1000 further comprises a switching transistor element 300, which also provides the recommended operating voltage V GSOPThe method comprises a device that has the applicable operating voltage and includes a third control terminal 302, wherein the switching transistor element 300 is connected in series between the first and second cascode transistor elements 100 and 200. The method includes supplying a first control voltage 104 to the first control terminal 102, supplying a second control voltage 204 to the second control terminal 202, and supplying a third control voltage 304 to the third control terminal 302. The method further includes adjusting the first control voltage 104 by means of a first source follower 500 connected to the first cascode transistor element 100 such that, during the ON state, the voltage difference between the first control voltage 104 and the input voltage U(t) is less than or equal to the applicable operating voltage.The method further comprises adjusting the second control voltage 204 by means of a second source follower 600, which is connected to the second cascode transistor element 200, such that during the ON state, the voltage difference between the second control voltage 204 and the input voltage U(t) is less than or equal to the applicable operating voltage. The method further comprises adjusting the third control voltage 304 by means of a third source follower 700, which is connected to the switching transistor element 300, such that during the ON state and during the OFF state, the voltage difference between the third control voltage 304 and the input voltage U(t) is less than or equal to the applicable operating voltage. A maximum voltage level U. maxThe input voltage level U(t) is higher than the applicable operating voltage. In the ON state, the control voltages 104, 204 and / or 304 may even remain at a value less than or equal to the recommended operating voltage V. GSOP is.

[0034] The method can be used to operate other switching circuit arrangements according to the embodiments described herein.

[0035] Another method for operating switching circuit arrangements that receive signals between an ON state and an OFF state according to the embodiments described herein can include providing a connection between a first port 1002 and a second port 1004 during the ON state and electrically disconnecting the first port 1002 from the second port 1004 during the OFF state. The switching circuit arrangement can comprise switching circuit sections arranged in series between a first port and a second port, each switching circuit section comprising a transistor element, wherein a first transistor element is arranged between and connected in series with a second and a third transistor element.The method may include applying the input voltage U(t) to the first port such that the input voltage U(t) includes a maximum voltage level that is higher than the applicable operating voltage, and may include controlling a control voltage of the first, second and third transistor elements of the switching circuit arrangement sections such that, during the ON state, an operating voltage of the first, second and third switching transistor elements between a control terminal and a power terminal of the switching transistor elements is less than or equal to the applicable operating voltage of the first, second and third switching transistor elements.

[0036] In other words, the charge pump can be configured to provide a voltage higher than the voltage to be switched, thus enabling overdriving of the voltages present in the circuit arrangement due to reception at input port 1002 or output port 1004.

[0037] Fig. Figure 2 shows a schematic block diagram of a switching circuit arrangement 2000 according to one embodiment. The switching circuit arrangement 2000 can be similar to the switching circuit arrangement 1000. The switching circuit arrangement 2000 comprises the transistor elements 100, 200, and 300, which are designated as T2, T3, and T1.

[0038] The switching circuit arrangement 2000 includes a supply signal arrangement 2400. The supply signal arrangement 2400 includes a port 2402 configured to receive a control signal 2403, specified as a power-on signal. The control signal 2403 can specify an operating mode, i.e., operation in the ON state or the OFF state of the switching circuit arrangement 2000, and / or can specify a transition between the ON state and the OFF state.

[0039] The supply signal arrangement 2400 can include the matching circuit arrangements 500, 600 and 700 and can be configured to provide the matched output voltages 104, 204 and 304 at the output ports 2404, 2406, 2408 respectively.

[0040] In other words, the switching circuit arrangement 2000 is a possible solution for realizing an input switch, i.e., a switching circuit arrangement, according to embodiments. The realization can comprise a stack of transistors, i.e., transistor elements 100, 200, and 300 connected in series, wherein the transistor elements 100, 200, and 300 may be of a lower voltage class compared to the input voltage U(t) with respect to the recommended or applicable operating voltage. The input voltage U(t) is defined as A in specified to indicate an analog value of the input voltage U(t). An output voltage provided by the switching circuit arrangement 2000 is designated as A out specified to indicate an analog value of the output voltage.

[0041] The switching circuit arrangement 2000 can involve an implementation of a so-called double stack, which means the use of transistor elements with nominal values ​​equal to half of the applicable voltage class, i.e., the recommended operating voltage is half of the maximum input voltage U. max , which can also be understood to mean that the maximum voltage level U max the input voltage U(t) is 100% higher than the recommended operating voltage V GSOP The concept can be extended to other classes, i.e., with larger or higher voltage, i.e., the maximum voltage level U. max The input voltage U(t) can be more than 200% of the recommended operating voltage V. GSOP to be, for example, the switching of a maximum voltage level U. max the input voltage U(t), which is at most five times the recommended operating voltage V GSOPTo enable this, four cascode transistor elements can be placed between the switching transistor element and the first port, and four cascode transistor elements can be placed between the switching transistor element and the second port. In simpler terms, the sum of the recommended operating voltages of the cascode transistor elements and the recommended operating voltage of the switching transistor element can specify a maximum switching voltage level. For example, to switch a maximum voltage level U max to enable 5 volts, with the recommended operating voltage V GSOP 1 volt allows the sum of four times V GSOP (4 x 1 Volt = 4 Volts) plus V GSOPThe switching transistor element (4 volts + 1 volt = 5 volts) allows switching up to 5 volts. Accordingly, at least one additional cascode transistor element can be connected between the switching transistor element and the first port, and at least one additional cascode transistor element can be connected between the second port and the switching transistor element. This enables the switching of microcontrollers that include transistor elements with a voltage class of 1 volt but also use a supply voltage of 5 volts.

[0042] The switching circuit arrangement 2000 comprises three transistor elements. The switching transistor element, i.e., the so-called real switching transistor, is in the middle of the series connection. On one side, a first cascode transistor 100 is arranged and is used to set the maximum input voltage U. maxThe input voltage for the real switch 300 is halved. On the other hand, a second cascode transistor 200 is used to halve the maximum voltage for the real switch from the output, i.e., for example, port 1004, using a summing node. It should be noted that the terms input port and output port are interchangeable and are used only for clarity.

[0043] All three transistors 100, 200 and 300 can be implemented with half the voltage class, which is derived from the maximum values ​​of A in and A outis defined. According to one example, only NMOS transistor elements are used for transistor elements 100, 200, and 300. According to other examples, which will be described later, a so-called T-GATE, comprising a PMOS and an NMOS, can be used to implement at least the switching transistor element 300. A T-GATE implementation allows the internal components to include high-voltage protection, which is less complicated to implement. Using NMOS-type transistor elements 100, 200, and 300 can provide increased protection for each individual transistor. In simplified terms, this shows Fig. 2 an analog input switch with stacked devices.

[0044] Fig. Figure 3 shows a schematic block diagram of a switching circuit arrangement 3000 according to the embodiments described herein. The switching circuit arrangement 3000 can be similar to the switching circuit arrangement 1000. The switching circuit arrangement 3000 comprises the supply signal arrangement 400. The supply signal arrangement 400 can include a current mirror comprising two current mirror branches 410 and 450 connected to a control potential V. CPare connected. The control potential can be higher than the maximum input voltage level and higher than the auxiliary signals. For example, the control voltage can be 7.5 volts. The first branch 410 can include a current source 412. The second branch 450 can include a current source 452. The first branch 410 can further include a switch 414 configured to provide a conductive operating mode during the ON state of the switching circuit arrangement 3000, as indicated by "ON" next to the switch 414. The first branch 410 also includes transistor elements 416 and 418, which can be, for example, p-type MOS transistor elements in a self-blocking configuration. The second branch 450 can include identical or comparable elements, i.e.,A switch 454 is configured to have a conductive operating mode in the ON state of the switching circuit arrangement and a non-conductive operating state in the OFF state of the switching circuit arrangement 3000. The second branch 450 may further comprise transistor elements 456 and 458, which are connected in series with each other and with the switching element 454 and the power source 452. The order of the elements of the first branch 410 and / or the second branch 450 may differ from the order illustrated and / or from each other. For example, the switching element 414 may be connected between the transistor element 418 and the control terminal of the cascode transistor element 100. Alternatively or additionally, the switching element 454 may be arranged between the transistor element 458 and the control terminal of the switching transistor element 300.The switching element 414 and / or the switching element 454 can, merely as a non-limiting example, be implemented as a transistor element. The switching element 454 can include a recommended operating voltage equal to that of the other transistor elements in the switching circuit arrangement 3000, but can also include a stacked configuration to allow higher voltages to be switched.

[0045] The control terminals of transistor elements 418 and 458 can be connected to one or more control voltages. For example, the input voltage and / or a first auxiliary signal, specified as Vcasc1, can be used as the control voltage. For example, the input voltage can be connected to the control terminals via a diode 472, and the first auxiliary signal Vcasc1 can also be connected to the control terminals via a diode 472. Diodes 472 and / or 474 can include a diode element and / or transistor elements. For example, diode 472 and / or 474 can include a transistor element, such as an n-type MOS transistor with a gate-drain bypass. Transistor elements 416 and 456 can be connected to a second auxiliary signal Vcasc2. The auxiliary signals Vcasc1 and Vcasc2 can be connected to the control terminals of their respective transistor elements and can be used to control the operation of the transistor elements. The potential VCPThe control voltage can be a high-voltage signal comprising a voltage level higher than the recommended or applicable operating voltage of transistor elements 416, 418, 456, and / or 458. A level of the auxiliary signals Vcasc 1 and / or Vcasc 2 can include such a voltage level, such that the voltage difference between the respective auxiliary signal and the potential at a source terminal of the respective transistor element is at most the applicable operating voltage. A control voltage 476 can be used to control one or more of the transistor elements of the switching circuit arrangement 3000. For input voltage levels below a certain limit, such as the recommended or applicable operating voltage, Vcasc 1 can be used to control the operation of transistor elements 418 and 458; that is, the control voltage 476 can be essentially equivalent to the first auxiliary signal Vcasc 1.For input voltage levels exceeding a certain limit, diodes 472 and 474 allow the input voltage level to be used to control transistor elements 472 and 474, so that the voltage difference between the power terminal and the control terminal of the transistor elements remains within the recommended or applicable voltage range. Accordingly, for high input voltage levels, the control voltage 476 can be essentially equal to the input voltage. In other words, a constant voltage Vcasc1 below the recommended operating voltage could cause an overvoltage at transistor element 418 if the input voltage increases above the cascode voltage level.By increasing the control voltage at transistor elements 418 and 458 by applying a higher voltage, such as the input voltage, the voltage difference can be kept within the limit of the applicable operating voltage. According to other examples, voltages other than the input voltage can be used to keep the voltage difference within predetermined limits. For example, an auxiliary signal, such as Vcasc2, can be used. Possible voltage levels are discussed in conjunction with... Fig. 5a and Fig. 5b is described in more detail. Vcasc2 can be a maximum or high voltage potential to be switched, whereas Vcasc1 can be equal to a voltage level that the transistor elements can withstand.

[0046] The control terminals of cascode transistor elements 100 and 200 can be connected to each other and can both be connected to the first branch 410 of the supply signal arrangement 400, which is hereinafter referred to as a charge pump configured to supply charge carriers to the control terminals of transistor elements 100, 200, and 300; that is, the supply signal arrangement 400 can include a charge pump circuit arrangement. The control terminal of switching transistor element 300 can be connected to the second branch 450 of the charge pump 400.

[0047] The switching circuit arrangement 3000 can include follower paths 500, 600, and 700. Follower path 500 can include a resistive element 502, designated RP2, a first transistor element 504, designated TP2, and a second transistor element 506, designated TC2. Transistor elements 504 and 506 are connected in series, with transistor element 506 connected to the reference potential 1006. A control terminal of transistor element 504 is connected to a power terminal of the first cascode transistor 100, such as a source terminal. The resistive element 502 can be connected between a power terminal of transistor element 504, such as a source terminal, and the control terminal of cascode transistor element 100. Follower paths 600 and 700 can include similar or identical elements, i.e.,The follower path 600 can comprise a resistive element 602, designated RP3, a first transistor element 604, designated TP3, and a second transistor element 606, designated TC3, while the follower path 700 can comprise a resistive element 702, designated RP1, a first transistor element 704, designated TP1, and a second transistor element 706, designated TC1. The resistance value of the resistive elements 502, 602, and / or 702 can be any suitable value, such as in the range between 1 kΩ and 100 MΩ, between 5 kΩ and 50 MΩ, or between 10 kΩ and 10 MΩ. The follower path 600 can be connected between the control terminal of the second cascode transistor element 200 and the reference potential 1006, and the follower path 700 can be connected between the control terminal of the switching transistor element 300 and the reference potential 1006.Follower paths 500 and 600 can be connected to each other in a parallel manner and can, for example, be connected to the first mirror path 410. Follower path 700 can be connected to the second mirror path 450.

[0048] Transistor elements 504, 604, and 704 can be connected to power terminals of cascode transistor elements 100 and / or 200 and / or to a power terminal of switching transistor element 300. In particular, the control terminals of transistor elements 504, 604, and / or 704 can be connected such that they each provide a connection between a control terminal of the respective transistor element 504, 604, and 704 and a power terminal of cascode transistor element 100 or 200 of switching transistor element 300. That is, the same potential can be applied to the control terminals of transistor element 504, transistor element 604, and transistor element 704 if cascode transistor elements 100 and 200 and switching transistor element 300 are operating in a conductive mode.

[0049] The switching circuit arrangement 3000 further comprises switching paths 550, 650, and 750. Switching path 550 can include a transistor element 552 and a switching element 554. The transistor element 552 and the switching element 554 can be connected to each other in series, with the series connection being between the control terminal of the cascode transistor element 100 and the reference potential 1006. Switching path 550 can be connected to the follower path 500 in parallel. Similarly, switching path 650 can include a transistor element 652 and a switching element 654 connected to each other in series, and can be connected to the follower path 600 in parallel, i.e., between the control terminal of the cascode transistor element 200 and the reference potential 1006.The switching path 750 can include a transistor element 752 and a switching element 754 connected to each other in series, wherein the switching path 750 can be connected in parallel to the follower path 700, i.e. between the control terminal of the switching transistor element 300 and the reference potential 1006.

[0050] The control terminals of transistors 552, 752, and 652 can be connected to each other and to the control voltage 476. The control terminals of the second transistors 506, 606, and 706 can be connected to each other and to the first auxiliary signal Vcasc1. The control terminals of transistors 552, 752, and 652 can be connected to each other and to the control voltage 476. As will be described in more detail later, the control voltage can be configured to control an operating mode of transistors 552, 752, and 652.

[0051] When comparing switching paths 550, 650, and 750, switching path 750, which is connected to switching transistor element 300, may exhibit a specific difference compared to switching paths 550 and 650. Transistor element 552 may be of a complementary transistor type compared to cascode transistor element 100. For example, cascode transistor element 100 may be of the n-type CMOS type, whereas transistor element 552 may be of the p-type CMOS type. Transistor element 652 may be of the same transistor type as transistor element 552 and may be of a complementary transistor type compared to cascode transistor element 200. For example, the transistor elements 552 and / or 652 can also be implemented as n-type CMOS and the cascode transistor elements 100 and 200 can be implemented as p-type CMOS.In contrast, the transistor element 752 can be of an equivalent or identical transistor type to the switching transistor element 300. For example, both transistor elements 752 and 300 can be implemented as n-type CMOS or p-type CMOS.

[0052] As indicated by "OFF", the switching elements 554 can be configured to connect the transistor elements 552, 652, 752 to the reference potential 1006 in the OFF state of the switching circuit arrangement 3000. The switching elements 554, 654, and / or 754 can be identical to the switching elements 414 and / or 454 except for their normally conducting or normally blocking operating mode, which can be complementary.

[0053] Although Fig. While a specific implementation of a switching circuit arrangement and matching circuit arrangements is illustrated in Figure 3, the teachings disclosed herein are not limited to these specific implementations. According to one aspect, the control voltages of transistor elements 100, 200, and 300 are controlled in such a way as to prevent damage due to overvoltages. According to embodiments, other circuit arrangements that control the control voltages can alternatively be implemented.

[0054] In other words, the use of unipolar (P- or NMOS) transistors with a lower voltage robustness than the analog input voltage can be an aspect of the embodiments described here for forming an analog switch. At least two transistors can be used in series for cascoding. At least one further transistor can be used to form the switch. Accordingly, the switching transistor element can be referred to as the real switch. This switch can be unipolar or bipolar (P- and NMOS as T-GATE) for a rail-to-rail operating scheme, with the possibility of adding a charge pump to overdrive the gate of the cascode and / or switching transistor. The real switch T1 can be positioned midway between the cascode transistor elements 100 and 200 and can be protected by the two cascodes T3 and T2, i.e., the cascode transistor elements 100 and 200.Three auxiliary bias voltages can be used, where one voltage level of Vcasc2 can be equal to a supply voltage level, such as VDDHV (e.g., 5 V), and one voltage level of Vcasc1 and / or Vcasc3 can be equal to a level of VDDHV / 2 (e.g., 2.5 V). Alternatively, Vcasc1 can be 2.5 V plus the threshold voltage of the transistor elements, such as 0.5 V. Vcasc1 and / or Vcasc3 can preferably be generated by a resistive divider that divides VDDHV. When the switching circuit arrangement is turned on, i.e., when it transitions to the ON state, the gate of T1 (of the switching transistor element 300) is turned on (high) by driving a current from the charge pump to a resistor, the resistive element 702. The resistor is clamped to the output of T1 by a source follower.Similar situations can be created by a second resistor 42 (cascode transistor element 100) and a third resistor 43 (resistive cascode element 200). This clamping will prevent an overvoltage if the input or output is close to 0 volts. When the switching circuit arrangement is turned off, i.e., when it transitions to the OFF state, all three gates are pulled to voltages lower than a source / drain voltage. However, the gates of transistor elements 100 (T2) and 200 (Te) are not pulled to ground to prevent overvoltages.

[0055] The two cascode transistor elements are pulled to a threshold (source follower) voltage that is higher than the average voltage Vcasc1. They will not be switched off if the input / output voltage is close to zero. The gate of T1 can be pulled to ground because the voltage at the source / drain of this transistor is no higher than Vcasc1.DD The value will be / 2, which is guaranteed by the two cascode transistor elements T2 and T3. T1 will therefore switch off for an input voltage close to 0 volts.

[0056] Fig. Figure 4 shows a schematic block diagram of another switching circuit arrangement 4000 according to a different embodiment. The switching circuit arrangement 4000 can be similar to the switching circuit arrangement 1000, 2000, or 3000. Compared to the switching circuit arrangement 3000, the supply signal arrangement can differ from the supply signal arrangement 400 of the switching circuit arrangement 3000. Furthermore, the switching transistor element can be implemented as a T-GATE circuit.

[0057] Attention is focused on the configuration of a supply signal arrangement 800, which is part of the switching circuit arrangement 4000. Compared to the supply signal arrangement 400, the supply signal arrangement 800 can include the current source 412. The switching element 414 and the transistor element 416 can be connected to each other as described for the first mirror path 410, with the supply signal arrangement 800 being implemented in the absence of the transistor element 418, so that a power terminal of the transistor element 416 can be connected to the control terminals of the cascode transistor elements 100 and 200. The current source 412 can be connected to the potential V CPbe connected to drive the current. A difference can now exist between the second mirror path 450 and a configuration of the current source 452, where the switching element 454 and the transistor element 458 are part of the supply signal arrangement 800. Instead of forming a current mirror with two branches connected to each other, the current source 452 can be connected to the first auxiliary signal Vcasc2 to drive the current for the switching element 350, the follower path 700, and / or the switching path 750. That is, instead of the potential V CP , which drives a current mirror as discussed for the supply signal arrangement 400, two different potentials V can CPand Vcasc2 are used to provide charge carriers for the switching circuit arrangement 4000. Supplying the power source 452 with the auxiliary signal Vcasc2 instead of a second branch of the current mirror can allow for a lower load for the charge pump. The auxiliary signal Vcasc2 can be a supply voltage applied to a switching circuit arrangement, such as a DC interface supply voltage. Such a power supply can be easier to load; that is, it can provide a higher amount of power without requiring additional or different elements to provide or combine the power.

[0058] The different supply signal arrangement 800, compared to the switching circuit arrangement 3000, allows for a simplified circuit arrangement of other elements of the switching circuit arrangement 4000. For example, the control terminals of transistor elements 552, 752, and 652 can be connected to each other and to the control terminals of the second transistor elements 506, 606, and 706. This allows a third auxiliary signal, Vcasc3, to be used as the control voltage. The third auxiliary signal, Vcasc3, can, for example, have a level corresponding to the recommended operating voltage, at least within a tolerance range. The tolerance range can be, for example, at most 10%, 20%, or 30% above or below the recommended operating voltage. Accordingly, the auxiliary signals Vcasc1 and Vcasc3 can be at the same potential. This allows both potentials to be connected together.The third auxiliary signal Vcasc3 can provide an advantage for input voltages that are higher than the recommended operating voltage, and can be compared to the one in conjunction with . Fig. The dynamic control voltage 476 described in section 3 can be static. Using static voltage levels can provide a simple circuit arrangement. Accordingly, an arrangement of diodes 472 and 474 may not be necessary.

[0059] Transistor elements 506, 552, 606, 652, and 706 can be p-type MOS transistors. This allows switching transistor element 300 to operate even in the absence of a supply voltage to the other transistor elements, thus ensuring a high level of safety.

[0060] The switching transistor element 350 can comprise a first transistor element 352 and a second transistor element 354, which are connected to each other according to a T-GATE configuration. In simplified terms, a T-GATE can be described as a source terminal of one transistor element 352 or 354 being connected to the drain terminal of the other transistor element 354 or 352, respectively. A control terminal of the transistor element 354 can be connected to the third auxiliary signal Vcasc3. Compared to the switching circuit arrangement 2000 or the switching circuit arrangement 3000, the transistor element 354 can be an additional transistor element connected to the transistor element 300 in such a way as to form a T-GATE circuit arrangement. In other words, an NMOS and a PMOS can form a T-GATE switch. The analog input voltage V incan be connected to the T-GATE. Alternatively, at least two T-GATEs can be used as a single switching transistor element and can be connected in series for better isolation. The analog input voltage V in It can be connected to at least one T-GATE. All T-GATE outputs can be connected to each other at a summing node. The summing node can be the input of an analog-to-digital converter (ADC) or a pin of a test multiplexer. The full voltage swing can occur on both sides of the T-GATE.

[0061] In other words, a high voltage can be switched using only low-voltage transistors, for example, 2.5 volts as the recommended operating voltage V. GSOPexhibit. That is, the switching circuit arrangement can be implemented in the absence of the transistor components that provide a supply voltage, sometimes referred to as V. DD is designated, for example, as 5.0 V, the recommended operating voltage V GSOP include. Accordingly, the embodiments described here can make it possible to avoid the need for a transistor that matches the voltage class of the application, such as a 5.0-volt application using a 5.0-volt transistor. The supply voltage V DD can refer to an integrated circuit that is integrated together with the switching circuit arrangement on a semiconductor substrate. A typical value of V DD It can be 5 volts. That is, the supply voltage V DD This could be the supply voltage of the integrated circuit. The maximum voltage level of the input voltage V incan correspond to the supply voltage of the integrated circuit. Accordingly, the recommended operating voltage V can GSOP equal to half of a supply voltage V DD of the integrated circuit.

[0062] Fig. Figure 5a illustrates a schematic block diagram of the ON state of the switching circuit arrangement 4000. The schematic block diagram also shows potential values ​​applied to transistor elements of the switching circuit arrangement 4000. These voltage levels are used only as examples and are not intended to limit the embodiments described here. In particular, based on other, additional, or different transistor elements, or different voltage levels to be switched by the switching circuit arrangement 4000, other, i.e., higher or lower, voltage levels can be used for each of the described voltage levels.

[0063] In the present example, an input voltage V can be used. in The input voltage, which can correspond to the input voltage U(t), lies between 0 volts and 5 volts. in The input port 1002 is to be switched to the output port 1004. In the ON state, switching elements 414 and 454 are conductive; for simplicity, the switches are closed. Switching elements 554, 654, and 754 can be in a high-impedance state; for simplicity, the switching elements can be OPEN.

[0064] A threshold voltage V th The transistor elements of the switching circuit arrangement 4000 are assumed to be 0.5 volts in this example. The transistor elements, in particular the cascode transistor elements and the switching transistor elements, can be implemented as transistor elements with 2.5 volts as the recommended operating voltage V. GSOPinclude. Accordingly, the recommended operating voltage V should be GSOP In the present example, if the operating voltage is 2.5 volts, the maximum applicable operating voltage should be, for example, 3.25 V, which corresponds to a permissible range (tolerance range) of 30% of the recommended voltage range. The auxiliary signals Vcasc1 and Vcasc3 should be equal to 2.5 volts and can be connected together, with the auxiliary signal Vcasc2 being equal to 5.0 volts. The charge pump voltage level of 7.5 volts can be obtained by adding the recommended operating voltage and the supply voltage. The configuration of the switching circuit arrangement 4000 and the operating mode may result in a voltage level equal to V in+2.5 V is applied to the control gate of the first cascode transistor element 100. Based on the parallel connection with the second cascode transistor element 200, the same voltage level is applied to the control terminal of the second cascode transistor element 200. The resistive elements 502 and 702 can be configured to provide a voltage drop equal to 2.0 volts. In combination with the voltage drop caused by the threshold voltage V th The voltage drop of 2.5 volts between the source terminal of the cascode transistor element 100 and its control terminal can be obtained due to the interference caused by the transistor element 504.

[0065] Accordingly, based on the charge pump that provides charge carriers, and based on the voltage applied to the control terminals of the cascode transistor elements 100 and 200, and the control terminal of the switching transistor element 352, a varying input voltage V can be generated. in This results in a varying voltage drop across the resistive elements, so that the circuit arrangement remains operational, i.e., the transistor elements of the circuit arrangement can be switched by the auxiliary signals and by the input voltage, with the voltage difference between the control terminal and the power terminal, for example the gate-source voltage, remaining within the limits of the recommended operating voltage V at the same time. GSOPand / or the applicable operating voltage. An example control voltage for the supply signal arrangement could be 7.5 volts. In simplified terms, during the ON state, a voltage drop across the respective resistive element adjusts the respective control voltage. In other words, during the ON state, a voltage drop across resistive element 502 can adjust the control voltage applied to cascode transistor element 100. Furthermore, during the ON state, a voltage drop across resistive element 602 can adjust the control voltage of cascode transistor element 200. Additionally, during the ON state, a voltage drop across resistive element 702 can adjust the control voltage of switching transistor element 352.

[0066] Accordingly, a voltage drop of 2.5 volts can be maintained within the recommended operating voltage range, even when an input voltage is applied that exceeds the recommended operating voltage V. GSOPand / or exceeds the applicable operating voltage. The same principles apply when attention is now turned to transistor element 458, which is connected to the current source 452. Although a voltage of 5.0 volts is applied to a source terminal of transistor element 458, a voltage difference of 2.5 volts between the control terminal and the power terminal of transistor element 458, based on the auxiliary signal Vcasc1, can occur within the range of the recommended operating voltage V. GSOP and / or the applicable operating voltage. Accordingly, the maximum input voltage can be higher than the recommended operating voltage and / or higher than the applicable operating voltage.

[0067] Based on the circuit arrangement of the supply signal arrangement, for input voltages that are at most the recommended operating voltage of 2.5 volts, a voltage that is also equal to the input voltage V is used. in +2.5 V is applied to the control terminal of switching transistor 352. For input voltages greater than the recommended operating voltage, the p-type MOS 354 is switched. If transistors 352 and 354 are saturated in a non-linear manner, the voltage applied to transistor 352 can be described by the following formula: min{Vin+2.5V;Vcasc2}

[0068] Accordingly, the voltage level at the control terminal of transistor 352 can be at most the level of the second auxiliary signal Vcasc2. A voltage of 2.5 volts is applied to a control terminal of transistor 354 for input voltages that are at most the recommended operating voltage of 2.5 volts. Therefore, voltages within the voltage range of the recommended operating voltage V can be applied to each transistor in the switching circuit arrangement. GSOP or at least the applicable operating voltage.

[0069] As with reference to Fig. As described in section 4, the supply signal arrangement can comprise a different configuration, such as the configuration of supply signal arrangement 400. There, a current mirror can be implemented, with one path of the current mirror being connected to the switching transistor element 350. Alternatively or additionally, the switching transistor element 300 can be arranged. Although they are described as being connected in parallel to each other, i.e., the current sources 412 are connected to the cascode transistor elements 100 and 200, at least one current source can be provided for each of the cascode transistor elements 100 and 200; that is, they can be connected in a configuration other than parallel to each other.

[0070] Fig. 5b shows the schematic block diagram from Fig. 5a, where the switching circuit arrangement 4000 includes the OFF state. In the OFF state, switching elements 554, 654, and 754 can be in a low-impedance state, i.e., the switches are closed, while switching elements 414 and 454 are in a high-impedance state. Based on this, a voltage of approximately 3.0 volts is applied to the control terminals of cascode transistor elements 100 and 200. The 3-volt level may be higher than the recommended operating voltage but may still be within the maximum applicable operating voltage, i.e., within the permissible range. This means that the cascode transistor elements 100 and 200 remain undamaged.In particular, in the OFF state, a small amount of current is carried between the first port 1002 and the second port 1004, and consequently through the cascode transistor elements 100 and 200. This can allow the voltage levels to rise above the recommended operating voltage without causing damage. In contrast, a voltage equal to the reference voltage 1006, for example, 0 volts, can be applied to the control terminal of the switching transistor element 352 or switching transistor element 300. This is possible because the transistor element 752 is an n-type CMOS transistor, like the switching transistor element 352 or switching transistor element 300.Based on the fact that the auxiliary signal Vcasc3 is connected to the control terminal of transistor element 752, and based on the closed state of switching element 754, the control terminal of switching transistor element 352 and switching transistor element 300 can each be connected to the reference voltage 1006. Based on the fact that the first cascode transistor element 100, the second cascode transistor element 200, and switching transistor element 352 or 300 have the same conductivity type, and / or based on the fact that the first cascode transistor element 100, the second cascode transistor element 200, and switching transistor element 352 or 300 are implemented by an identical transistor type, a symmetrical circuit arrangement can be obtained accordingly. Based on the fact that transistor element 752, compared to switching transistor element 352 or 300, is of the same conductivity type, a symmetrical circuit arrangement can be obtained.If the 300 is of the same type, the so-called real switch can be connected to the reference voltage, i.e., switched to 0.

[0071] In the ON state from Fig. 5a. Voltages applied to the transistor elements can be below or equal to the applicable operating voltage, or even below or equal to the recommended operating voltage. In the OFF state, Fig. 5b The voltage may exceed the recommended operating voltage within the tolerance range of the applicable operating voltage.

[0072] The symmetry of the circuit arrangements according to the present embodiments allows the first and second cascode transistor elements 100 and 200 and the switching transistor elements 352 and 354 or 300 to be implemented as so-called double-gate oxide transistors. Furthermore, the switching circuit arrangements 1000, 2000, 3000, and / or 4000 can be implemented by transistor elements of the same or equivalent manufacturing process. Compared to known switching circuit arrangements, the arrangement of a switching transistor that differs from other transistor elements of the circuit arrangement can be avoided. This can enable a common manufacturing process that can be implemented with a short time investment, which can allow for high process throughput and / or low implementation costs for the switching circuit arrangement.

[0073] The voltage level on the so-called input side between the first port 1002 and the transistor element 352 can be at most 2.5 volts. The voltage level on the so-called output side between the second port 1004 and the transistor element 352 can be at most 2.5 volts. In particular, both voltage levels can follow the following rule of determination: min{Vin;2.5V}

[0074] In simplified terms, the voltage levels of the input voltage V can be inThe input voltage level can be adjusted up to 2.5 volts when the cascode transistor element 100 turns on. At low voltages, e.g., 0 volts, the cascode transistor element 100 can operate in a conductive mode. For input voltage levels above 2.5 volts, the cascode transistor element 100 provides cascode functionality, i.e., the voltage level is limited. The input voltage level can follow the voltage level at the first port 1002, while the output voltage level can follow the voltage level at the second port according to the determining rule. min{Vout;2,5V}

[0075] In the case relating to Fig. 5a and Fig. In the embodiment described in 5b, the recommended operating voltage V GSOP equal to half the maximum input voltage level of the input voltage V inAccording to other embodiments, a different relationship may exist between the recommended operating voltage V. GSOP and the maximum input voltage level of the input voltage V in The relationship can be obtained through the input voltage and / or the recommended operating voltage V. GSOP They can be influenced independently of each other. Furthermore, the switching circuit arrangements according to the embodiments described here can be varied so that a different relationship exists between the maximum input voltage level and the input voltage V. inand the recommended operating voltage is enabled. For example, when reference is made to the source follower path 500 or any other source follower described here, a voltage drop can be obtained across the resistive element 502, across the transistor element 504, and across the transistor element 506. Each of the elements enables a voltage drop in the range of 2.5 volts between the voltage V CP from 7.5 volts down to the reference voltage of 1006. Accordingly, if, for example, a higher input voltage is used and therefore a higher voltage V is required, CP The same type of transistor elements is used when additional transistor elements are used, thus enabling further voltage drops between the highest voltage and the reference voltage.

[0076] Fig.Figure 6 shows a schematic block diagram of a DC voltage interface 6000 according to one embodiment. The DC voltage interface 6000 can comprise the switching circuit arrangement 1000. Alternatively or additionally, the DC voltage interface 6000 can comprise another switching circuit arrangement according to embodiments described herein, such as the switching circuit arrangement 2000, the switching circuit arrangement 3000, and / or the switching circuit arrangement 4000. The DC voltage interface 6000 can be supplied by a supply voltage V DD For example, 5.0 volts can be supplied with power. An integrated circuit 6100 with the switching circuit arrangement 1000 can supply the voltage V DD They can be used as the supply voltage. Furthermore, low-voltage transistor elements can be used to ensure protection of the cascode and the switching transistor elements.

[0077] The DC interface can, for example, be a sensor interface that can be connected to a power sink, such as at least one microcontroller and / or at least one sensor element. For example, a Hall sensor, a knock sensor, and / or a low-frequency sensor using frequencies below 1 MHz can be connected to the second sensor port 1004 of the switching circuit arrangement 3000. Alternatively or additionally, several power sinks can be connected to the second port. This can, for example, enable multiplexing of several sensors that are connected to the second port.

[0078] The embodiments described here can enable the safe switching of voltages that are higher than a recommended operating voltage and / or an applicable operating voltage of the transistor elements used for switching.

[0079] Although some aspects have been described in the context of a facility, it is understood that these aspects also represent a description of the corresponding process, where a block or device corresponds to a process step or a feature of a process step. Similarly, aspects described in the context of a process step also represent a description of a corresponding block, object, or feature of a corresponding facility.

[0080] The embodiments described above are merely illustrative of the principles of this disclosure. It is understood that modifications and variations of the arrangements and the details described herein will be apparent to a person skilled in the art. Therefore, it is intended that the scope of protection be limited only by the pending claims and not by the specific details presented here in the description and explanation of the embodiments.

Claims

[1] Switching circuit arrangement (1000; 2000; 3000; 4000) for providing during an ON state a connection between a first port (1002) for receiving an input voltage (Vin; U(t)) and a second port (1004) and for electrically disconnecting during an OFF state of the first port (1002) from the second port (1004), wherein the switching circuit arrangement comprises: a first cascode transistor element (100) having an applicable operating voltage and comprising a first control terminal (102), wherein the first cascode transistor element (100) is connected to the first port (1002) of the switching circuit arrangement; and a second cascode transistor element (200) which also has the applicable operating voltage and includes a second control terminal (202), wherein the second cascode transistor element (200) is connected to the second port (1004) of the switching circuit arrangement; a switching transistor element (300; 350) which also provides the applicable operating voltage and includes a third control terminal (302), wherein the switching transistor element (300; 350) is connected in series between the first (100) and second (200) cascode transistor elements; and a supply signal arrangement (400; 800) connected to the first (102), second (202) and third (302) control terminals and configured to supply a first control voltage (104) to the first control terminal (102), to supply a second control voltage (204) to the second control terminal (202) and to supply a third control voltage (304) to the third control terminal (302); wherein the first cascode transistor element (100) is connected to a first matching circuit arrangement (500), the first matching circuit arrangement (500) is connected between the first control terminal (102) and a reference potential (1006) and is configured to match the first control voltage (104) such that during the ON state the voltage difference between the first control voltage (104) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; wherein the second cascode transistor element (200) is connected to a second matching circuit arrangement (600), wherein the second matching circuit arrangement (600) is connected between the second control terminal (202) and the reference potential (1006) and is configured to adjust the second control voltage (204) such that during the ON state the voltage difference between the second control voltage (204) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; wherein the switching transistor element (300; 350) is connected to a third matching circuit arrangement (700), the third matching circuit arrangement (700) being connected between the third control terminal (302) and the reference potential (1006) and being configured to adjust the third control voltage (304) such that, during the ON state, the voltage difference between the third control voltage (304) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; and where a maximum voltage level (U max ) the input voltage (Vin; U(t)) is higher than the applicable operating voltage. [2] Switching circuit arrangement according to claim 1, wherein the first adaptation circuit arrangement (500) is configured to adapt the first control voltage (104) such that during the OFF state the voltage difference between the first control voltage (104) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; wherein the second adaptation circuit arrangement (600) is configured to adapt the second control voltage (204) such that during the OFF state the voltage difference between the second control voltage (204) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; and wherein the third adaptation circuit arrangement (700) is configured to adapt the third control voltage (304) such that during the OFF state the voltage difference between the third control voltage (304) and the input voltage (Vin;U(t)) is less than or equal to the applicable operating voltage.; [3] Switching circuit arrangement according to claim 1 or 2, wherein the applicable operating voltage is within a tolerance range higher than a recommended operating voltage (V GSOP ) of the first cascode transistor element (100), the second cascode transistor element (200) and the switching transistor element (300), wherein the tolerance range is at most 35% of the recommended operating voltage (V GSOP ) is. [4] Switching circuit arrangement according to one of the preceding claims, wherein the first matching circuit arrangement (500) comprises a first source follower with a first resistive element (502), wherein during the ON state a voltage drop across the first resistive element (502) matches the first control voltage (104); wherein the second matching circuit arrangement (600) comprises a second source follower with a second resistive element (602), wherein during the ON state a voltage drop across the second resistive element (602) matches the second control voltage (204); wherein the third matching circuit arrangement (700) comprises a third source follower with a third resistive element (702), wherein during the ON state a voltage drop across the third resistive element (702) matches the third control voltage (304). [5] Switching circuit arrangement according to one of the preceding claims, wherein the supply signal arrangement (400; 800) comprises a charge pump circuit arrangement. [6] Switching circuit arrangement according to claim 5, wherein the charge pump circuit arrangement further comprises a current mirror circuit arrangement, wherein the current mirror circuit arrangement comprises a first branch (410) connected to the first and second source followers, and a second branch (450) connected to the third source follower. [7] Switching circuit arrangement according to one of the preceding claims, wherein the first matching circuit arrangement (500) comprises a fourth transistor element (552), wherein during the OFF state the fourth transistor element (552) is connected between the first control terminal (102) and the reference potential (1006); wherein the second matching circuit arrangement (600) comprises a fifth transistor element (652), wherein during the OFF state the fifth transistor element (652) is connected between the second control terminal (202) and the reference potential (1006); and wherein the third matching circuit arrangement (700) comprises a sixth transistor element (752), wherein during the OFF state the sixth transistor element (752) is connected between the third control terminal (302) and the reference potential (1006). [8] Switching circuit arrangement according to claim 7, wherein the fourth transistor element (552) and the first cascode transistor element (100) have complementary transistor types; wherein the fifth transistor element (652) and the second cascode transistor element (200) have complementary transistor types; wherein the sixth transistor element (752) and the switching transistor element (300; 350) have the same transistor type. [9] Switching circuit arrangement according to claim 7 or 8, wherein the fourth transistor element (552) comprises a fourth control terminal, wherein the fifth transistor element (652) comprises a fifth control terminal and wherein the sixth transistor element (752) comprises a sixth control terminal, wherein during the OFF state the fourth (552), fifth (652) and sixth (752) control terminals are connected to a voltage level (Vcasc1; Vcasc3) corresponding to an applicable operating voltage of the fourth, fifth and sixth transistor elements (552, 652, 752). [10] Switching circuit arrangement according to one of the preceding claims, wherein the first (100) and second (200) cascode transistor element and the switching transistor element (300; 350) have the same conductivity type. [11] Switching circuit arrangement according to one of the preceding claims, wherein the first (100) and second (200) cascode transistor element and the switching transistor element (300; 350) are implemented by an identical transistor type. [12] Switching circuit arrangement according to one of claims 1 to 9, wherein the switching transistor element (300; 350) is implemented as a T-GATE circuit (350). [13] Switching circuit arrangement according to one of the preceding claims, wherein the first cascode transistor element (100), the second cascode transistor element (200) and the switching transistor element (300; 350) are implemented as double-gate oxide transistors. [14] Switching circuit arrangement according to one of the preceding claims, wherein the first cascode transistor element (100), the second cascode transistor element (200) and the switching transistor element (300; 350) have a recommended operating voltage (V) of 2.5 V. GSOP exhibit. [15] Switching circuit arrangement according to one of the preceding claims, wherein the switching circuit arrangement is implemented in the absence of transistor elements that provide a supply voltage level (V DD ) of an integrated circuit (6100) which is integrated together with the switching circuit arrangement on a semiconductor substrate, as the recommended operating voltage (V GSOP ) include. [16] Switching circuit arrangement according to one of the preceding claims, wherein the maximum voltage level (U max ) the input voltage (Vin; U(t)) a supply voltage level (V DD ) of an integrated circuit (6100) which is integrated together with the switching circuit arrangement on a semiconductor substrate. [17] Switching circuit arrangement according to one of the preceding claims, wherein a recommended operating voltage (V GSOP) of the first cascode transistor element (100), the second cascode transistor element (200) and the switching transistor element (300) equal to half the maximum level of the input voltage (U max ) of the input voltage (Vin; U(t)). [18] Switching circuit arrangement according to one of the preceding claims, wherein a recommended operating voltage (V GSOP ) of the first cascode transistor element (100), the second cascode transistor element (200) and the switching transistor element (300) equal to half a supply voltage level (V DD ) of an integrated circuit (6100) which is integrated together with the switching circuit arrangement on a semiconductor substrate. [19] Switching circuit arrangement according to one of the preceding claims, wherein at least a third cascode transistor element is connected between the switching transistor element (300) and the first port (1002) and wherein at least a fourth cascode transistor element is connected between the second port (1004) and the switching transistor element (300). [20] DC interface (6000) comprising a circuit arrangement (1000; 2000; 3000; 4000) according to any of the preceding claims. [21] Method for operating a switching circuit arrangement which receives an input voltage (Vin; U(t)) between an ON state and an OFF state, the method comprising: Providing a connection between a first port (1002) and a second port (1004) during the ON state and electrically disconnecting the first port (1002) from the second port (1004) during the OFF state; the switching circuit arrangement comprises the following: a first cascode transistor element (100) having an applicable operating voltage and comprising a first control terminal (102), wherein the first cascode transistor element (100) is connected to the first port (1002) of the switching circuit arrangement; and a second cascode transistor element (200) which also has the applicable operating voltage and includes a second control terminal (202), wherein the second cascode transistor element (200) is connected to the second port (1004) of the switching circuit arrangement; a switching transistor element (300; 350) which also has the applicable recommended operating voltage and includes a third control terminal (302), wherein the switching transistor element (300; 350) is connected in series between the first and second cascode transistor elements (200); and Supplying a first control voltage (104) to the first control terminal (102); Supplying a second control voltage (204) to the second control terminal (202); Supplying a third control voltage (304) to the third control terminal (302); Adjusting the first control voltage (104) by means of a first source follower connected to the first cascode transistor element (100) so that during the ON state the voltage difference between the first control voltage (104) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; Adjusting the second control voltage (204) by means of a second source follower connected to the second cascode transistor element (200) such that during the ON state the voltage difference between the second control voltage (204) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; and Adjusting the third control voltage (304) by means of a third source follower connected to the switching transistor element (300; 350) so that during the ON state the voltage difference between the third control voltage (304) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; where a maximum voltage level (U max ) the input voltage (Vin; U(t)) is higher than the applicable operating voltage. [22] The method of claim 21, further comprising: Adjusting the first control voltage (104) so ​​that during the OFF state the voltage difference between the first control voltage (104) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; Adjusting the second control voltage (204) so ​​that during the OFF state the voltage difference between the second control voltage (204) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage; and Adjusting the third control voltage (304) so ​​that during the OFF state the voltage difference between the third control voltage (304) and the input voltage (Vin; U(t)) is less than or equal to the applicable operating voltage. [23] Method according to claim 21 or 22, wherein the applicable operating voltage is within a tolerance range higher than a recommended operating voltage (V) GSOP ) of the first cascode transistor element (100), the second cascode transistor element (200) and the switching transistor element (300), wherein the tolerance range is at most 35% of the recommended operating voltage (V GSOP ) is.

Images