阅读说明：本技术 电平转换器以及用于在车辆控制设备中转换电平值的方法 (Level converter and method for converting level value in vehicle control apparatus ) 是由 T·福伊希特 于 2018-06-12 设计创作，主要内容包括：一种用于车辆控制设备的电平转换器,所述电平转换器包括：第一电压连接端(110)、第二电压连接端(120)、输出连接端(OUT)和输入连接端(IN)。此外,所述电平转换器包括第一开关(S1),所述第一开关用于对所述第一电压连接端(110)与所述输出连接端(OUT)之间的第一电流路径进行通断；第二开关(S2),所述第二开关用于对所述第二电压连接端(120)与所述输出连接端(OUT)之间的第二电流路径进行通断。所述第一开关(S1)和所述第二开关(S2)能够响应于所述输入连接端(IN)上的不同电平水平如此通断,使得在所述输入连接端(IN)上施加第一电平水平的情况下,所述第一开关(S1)闭合并且所述第二开关(S2)断开,并且在施加第二电平水平的情况下,所述第一开关(S1)断开并且所述第二开关(S2)闭合。(A level shifter for a vehicle control apparatus, the level shifter comprising: a first voltage connection (110), a second voltage connection (120), an output connection (OUT) and an input connection (IN). Furthermore, the level shifter comprises a first switch (S1) for switching a first current path between the first voltage connection (110) and the output connection (OUT); a second switch (S2) for switching a second current path between the second voltage connection (120) and the output connection (OUT). The first switch (S1) and the second switch (S2) can be switched IN response to different level levels at the input connection (IN) IN such a way that, when a first level is applied to the input connection (IN), the first switch (S1) is closed and the second switch (S2) is open, and when a second level is applied, the first switch (S1) is open and the second switch (S2) is closed.)

1. A level shifter for a vehicle control apparatus, the level shifter having the following features:

it is characterized in that

A first voltage connection (110), a second voltage connection (120), at least one output connection (OUT; OUT1, OUT2) and an input connection (IN);

a first switch (S1) for switching a first current path between the first voltage connection (110) and the at least one output connection (OUT) or one of the output connections (OUT 1);

a second switch (S2) for switching a second current path between the second voltage connection (120) and the at least one output connection (OUT) or another of the output connections (OUT2),

wherein the first switch (S1) and the second switch (S2) can be switched IN response to different level levels at the input connection (IN) IN such a way that

IN the case of a first level being applied to the input connection (IN), the first switch (S1) is closed and the second switch (S2) is opened,

with the second level applied, the first switch (S1) is opened and the second switch (S2) is closed.

2. The level shifter of claim 1, wherein the first and second switches are connected to a common voltage source,

it is characterized in that the preparation method is characterized in that,

the first switch (S1) and the second switch (S2) are designed such that, when a third level is applied to the input connection (IN), the first switch (S1) and the second switch (S2) are open, wherein the third level lies IN particular between the first level and the second level.

3. Level shifter according to claim 2, wherein the first switch (S1) and the second switch (S2) each have a control connection for switching the first switch (S1) and the second switch (S2) by means of a control signal,

it is characterized in that

A control circuit (200) having a reference voltage unit (220) for controlling the control connections of the first switch (S1) and of the second switch (S2), wherein the reference voltage unit (220) is designed to provide the third level such that the first switch (S1) and the second switch (S2) are opened when the input connection (IN) is switched to a high impedance.

4. The level shifter of claim 3 wherein the first and second switches are connected in parallel,

it is characterized in that the preparation method is characterized in that,

the steering circuit (200) comprises the following:

a third switch (S3) connected between the input connection (IN) and the control connection of the first switch (S1);

a fourth switch (S4) connected between the input connection (IN) and the control connection of the second switch (S2),

wherein the third switch (S3) is closed with the first level applied on the input connection (IN), and the fourth switch (S4) is closed with the second level applied on the input connection (IN).

5. Level shifter according to claim 3 or 4,

it is characterized in that the preparation method is characterized in that,

the reference voltage unit (220) has a voltage divider with a third voltage connection (130) and a fourth voltage connection (140) in order to provide a reference voltage for realizing the third level.

6. The level shifter of claim 5 wherein the first and second switches are connected in series,

it is characterized in that the preparation method is characterized in that,

the voltage divider, the first switch (S1), and the second switch (S2) are drivable by means of: a voltage in the range between 3V and 5V at the third voltage connection (130); a ground potential at the fourth voltage connection (140) and at the second voltage connection (120); a voltage of at least 5V at the first voltage connection (110).

7. Level shifter according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the first switch (S1), the second switch (S2), the third switch (S3), and the fourth switch (S4) have transistors, wherein the transistor of the first switch (S1) is complementary to the transistor of the second switch (S2), and the transistor of the third switch (S3) is complementary to the transistor of the fourth switch (S4).

8. Level shifter according to any one of claims 3 to 7,

it is characterized in that

A plurality of resistors having one or more of the following resistances:

a first resistor (R1) between the input connection (IN) and the control connection of the first switch (S1),

a second resistor (R2) between the input connection (IN) and the control connection of the second switch (S2),

a third resistor (R3) between the control connection of the first switch (S1) and the first voltage connection (110),

a fourth resistor (R4) between the control connection of the second switch (S2) and the second voltage connection (120),

a fifth resistor (R5) between the input connection (IN) and the control connection of the third switch (S3) and of the fourth switch (S4),

a sixth resistor (R6) between the third voltage connection (130) and the control connection of the third switch (S3),

a seventh resistor (R7) between the fourth voltage connection (140) and the control connection of the fourth switch (S4), wherein the sixth resistor (R6) and the seventh resistor (R7) are connected in series between the third voltage connection (130) and the fourth voltage connection (140).

9. Level shifter according to any of the preceding claims,

it is characterized in that

An eighth resistance (R8) between the first switch (S1) and the second switch (S2) along the first current path.

10. Level shifter according to any of the preceding claims,

it is characterized in that

A diode (D1) between the first switch (S1) and the at least one output connection (OUT) or one of the output connections (OUT1), the diode being designed to prevent a backflow current between the output connection (OUT) and the first voltage connection (110).

11. Level shifter according to any of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the at least one output connection (OUT1, OUT2) comprises the one output connection (OUT1) and the other output connection (OUT2), wherein the first switch (S1) and the second switch (S2) are switchable IN response to different level levels at the input connection (IN) IN such a way that at least one of the output connections (OUT1, OUT2) switches to a high impedance.

12. A control device of a vehicle, in particular of a commercial vehicle, having a level shifter according to any one of claims 1 to 11.

13. A commercial vehicle having a control device according to claim 12.

14. A method for converting a level value in a vehicle control apparatus,

it is characterized in that the preparation method is characterized in that,

switching a first current path between the first voltage connection (110) and the at least one output connection (OUT) or one of the output connections (OUT1) by means of a first switch (S1);

switching a second current path between a second voltage connection (120) and the at least one output connection (OUT) or the other of the output connections (OUT2) by means of a second switch (S2),

wherein the first switch (S1) and the second switch (S2) are switched IN response to different level levels at the input connection (IN) IN such a way that

IN the case of a first level being applied to the input connection (IN), the first switch (S1) is closed and the second switch (S2) is opened, and

with the second level applied, the first switch (S1) is opened and the second switch (S2) is closed.

15. Use of a level shifter according to any one of claims 1 to 11 for testing control equipment, in particular for determining short circuits.

Technical Field

The present invention relates to a level shifter for a vehicle control device and a method for shifting level values in a vehicle control device, and in particular to a three-state level shifter (having 3 states) in a safety-critical system.

Background

In automotive technology and in particular in safety-critical systems, it is often necessary to set level values to a plurality of adjustable levels or states. For example, the voltage value is 0V or 5V, or is in a high resistance state. Safety-critical systems include, for example: ABS (antilock braking system), EBS (electronic brake system), ESP (electronic stability program), or transmission controller.

For example, the mentioned conversion into three states (so-called three-state systems) is used to load an analog signal having three different voltage values or to place the analog signal at a defined level. Switching to the respective voltage values is triggered by means of signal lines (computer ports), for example in EBS5.x and EBS 7. It is likewise possible to implement level shifting with two voltage levels by means of an integrated circuit and one computer port, or with three voltage levels by means of two computer ports.

However, three voltage values (tri-states) need to be level-converted by means of only one signal line. Furthermore, more cost and resources should be saved at the level shifting.

Disclosure of Invention

At least part of the above mentioned problems of conventional systems are solved by a level shifter according to claim 1 and a method for shifting level values according to claim 13.

The present invention relates to a level shifter for a vehicle control apparatus. The level shifter includes a first voltage connection, a second voltage connection, an input connection, and at least one output connection. Further, the level shifter includes a first switch and a second switch. The first switch is designed to switch a first current path between the first voltage connection and the at least one output connection (or one of the output connections). The second switch is designed to switch a second current path between the second voltage connection and the at least one output connection (or another of the output connections). The first switch and the second switch are switched on and off in response to different levels on the input connection in such a way that: (i) in case a first level is applied on the input connection, the first switch is closed and the second switch is open, and (ii) in case a second level is applied, the first switch is open and the second switch is closed.

Within the scope of the invention, a switch connected between two elements should be understood as an electrical component: the electrical component opens or closes a current path between two elements (e.g. between the first/second voltage connection and the respective output connection) in response to a control signal. The first switch and the second switch may be complementarily

Switching on and off in response to a change in the level on the input connection. For example, the switching may be performed in parallel when the level changes, but the switching may be performed with a time shift (in series). But both switches should not be closed at the same time.

However, the first switch and the second switch may be configured to: in case a third level is applied to the input connection, both switches are open. Alternatively, the third level may be between the first level and the second level.

The level can be understood, for example, as a defined voltage value. It should be understood that the level may be within a certain range of voltage values, wherein for any voltage within the mentioned range a defined circuit state (open or closed) is assumed. The three level levels can thus define three ranges of voltage values at the input connection for which the desired level values are reached at the output connection. For the plurality of output connections, at least one of the plurality of output connections is always high-impedance, and a corresponding level value is present at the other output connection (which is not high-impedance). The desired level value is achieved by the voltage values at the first voltage connection and the second voltage connection. The three level values at the input connection in particular need not be correlated with the voltage values at the first voltage connection and the second voltage connection. For example, a low (high) level on the input connection may result in a high (low) level on the output connection.

In other embodiments, a control circuit for implementing on-off operation may be provided. The switch itself and the control circuit can have different components (e.g. one or more transistors), so that the respective switching operation can in principle be configured arbitrarily. Therefore, a low (high) level on the input connection may also result in a low (high) level on the output connection.

The first switch and the second switch may each have a control connection to turn the first switch and the second switch on and off, respectively, in response to a control signal. Optionally, the level shifter comprises a control circuit having a reference voltage unit for controlling the control connections of the first and second switches. The reference voltage unit is designed, for example, to provide a third level, so that the first switch and the second switch are opened when the input connection is switched to a high impedance. The method is realized by a reference voltage unit: when no signal is applied to the input connection (i.e., the input connection is high impedance), the first switch and the second switch are open.

Optionally, the steering circuit comprises the following: a third switch connected between the input connection terminal and the control connection terminal of the first switch; a fourth switch connected between the input connection terminal and the control connection terminal of the second switch. The third switch may be closed in case a first level is applied on the input connection. The fourth switch may be closed with the second level applied on the input connection. Optionally, the reference voltage unit comprises a voltage divider with a third voltage connection and a fourth voltage connection for providing a reference voltage for achieving the third level.

Alternatively, the voltage divider, the first switch and the second switch can be driven by means of the following voltages: a voltage in the range between 3V and 5V can be applied to the third voltage connection, a ground potential can be applied to the fourth voltage connection and to the second voltage connection, and a voltage of at least 5V (or 10V, 12V, 20V, 32V …) can be applied to the first voltage connection.

Optionally, the first switch and/or the second switch and/or the third switch and/or the fourth switch is or comprises a transistor, wherein the transistor of the first switch is complementary to the transistor of the second switch and the transistor of the third switch is complementary to the transistor of the fourth switch. The transistor may be a bipolar transistor or a Field Effect Transistor (FET).

Optionally, the level shifter comprises a plurality of resistors having one or more of the following resistances:

a first resistor between the input connection (or the third switch) and the control connection of the first switch,

a second resistor between the input connection (or fourth switch) and the control connection of the second switch,

a third resistor between the control connection of the first switch and the first voltage connection,

a fourth resistor between the control connection of the second switch and the second voltage connection,

a fifth resistor between the input connection and the control connection of the third switch and/or the fourth switch,

a sixth resistor between the third voltage connection and the control connection of the third switch,

a seventh resistor between the fourth voltage connection and the control connection of the fourth switch.

Further, the level shifter may have an eighth resistance between the first switch and the second switch. Likewise, the level shifter can have a diode between the first switch and the output connection, which diode is designed to prevent a backflow current between the output connection and the first voltage connection (i.e. in the opposite direction to the current flow when the first switch is closed).

Alternatively, at least one output connection can have two output connections, i.e. comprise one output connection and another output connection, wherein the first switch and the second switch can be switched in response to different levels at the input connections in such a way that at least one of the output connections switches to a high impedance.

The invention also relates to a control device for a vehicle, in particular a commercial vehicle, having one of the aforementioned level converters. The invention also relates to a commercial vehicle having such a control device.

Furthermore, the invention relates to a method for converting a level value in a vehicle control apparatus. The method comprises the following steps:

switching a first current path between the first voltage connection and one of the output connections or the output connection by means of a first switch;

switching a second current path between the second voltage connection and the other of the one or the other output connection by means of a second switch;

wherein the first switch and the second switch are switched on and off in response to different level levels at the input connection terminal in such a way that

In case a first level is applied on the input connection, the first switch is closed and the second switch is open,

-in case a second level is applied, the first switch is open and the second switch is closed.

The invention also relates to the use of one of the above-described level shifters for testing control devices, in particular for determining short circuits. By means of the different level values, it can be determined (for example by means of current measurement) whether a short circuit to ground or to the operating voltage exists for the different potential levels.

The embodiments described provide, inter alia, the following advantages over the prior art:

only one signal line (computer PIN) is needed to perform the 3-state level conversion. This results in saving on computer resources.

The level shifter may use discrete components so that it can convert to any output voltage.

In principle, a level conversion to an arbitrary level value, in particular also to a level value higher than the input voltage, can be carried out.

By periodically activating the circuits with three input levels, for example LOW (0V), open (HIGH impedance) and HIGH (for example 5V), level shifters can be used for testing purposes, wherein the circuit to be tested is activated in a targeted manner with the aid of the respective voltage level in order to determine which potential level a short circuit has occurred.

No special components are required.

Monitoring of analog signals, final stages or voltage limiting circuits can be realized, for example, without a large amount of overhead.

Embodiments of the invention will be better understood from the following detailed description of various embodiments and the accompanying drawings, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.

Drawings

FIG. 1 shows a schematic circuit diagram of a level shifter according to an embodiment of the present invention;

fig. 2 shows an embodiment with a specific implementation of complementary transistors as switches;

FIG. 3 shows further alternative details of the embodiment in FIG. 2;

fig. 4 shows a further exemplary embodiment of a level shifter with two output connections.

Detailed Description

Fig. 1 shows a schematic circuit diagram of a level shifter according to an embodiment of the present invention. The level shifter may be used, for example, in or for a vehicle control device, and includes: a first voltage connection 110, a second voltage connection 120, an output connection OUT, an input connection IN, a first switch 110 and a second switch 120. The first switch S1 is used to open and close a first current path between the first voltage terminal 110 and the output terminal OUT. The second switch S2 is used to switch the second current path between the second voltage terminal 120 and the output terminal OUT. The first switch S1 and the second switch S2 can be switched IN response to different level levels at the input connection IN such a way that (i) when a first level is applied to the input connection IN, the first switch S1 is closed and the second switch S2 is open, (ii) when a second level is applied, the first switch S1 is open and the second switch S2 is closed.

The first level may be, for example, a high voltage and the second level may be, for example, a low voltage. Furthermore, the first switch S1 and the second switch S2 may be selected such that the first switch and the second switch are open at a third level (between the first level and the second level).

Furthermore, the first switch S1 and the second switch S2 each comprise a control connection, which are coupled to the input connection IN. The mentioned level is applied to the control connection, for example, in order to achieve the desired switching operation.

The illustrated level shifter is thus able to realize three states at the output connection OUT by specifically activating the input connection IN. The first state is given, for example, by: not only the first switch S1 but also the second switch S2 is turned off, so that the output connection OUT is high-resistive (not applied with a defined voltage value). The second state may be realized, for example, by: the first switch S1 is closed, but the second switch S2 remains open, which is realized by a corresponding level value at the input connection IN. The second state results in: the voltage value + V of the first voltage connection 110 is applied to the output connection OUT. The third state can be realized by opening the first switch S1 and closing the second switch S2, which results in the level value at the output connection OUT being placed at the following voltage: the voltage is applied to the second voltage connection 120 (for example ground potential). The voltage V + at the first voltage connection 110 can be selected arbitrarily.

The circuit diagram may be implemented, for example, as follows: the switches S1, S2 are configured complementary to one another, i.e., the following level values are always present: for said level values, one switch is open and the other switch is closed, but both switches cannot be closed at the same time. Alternatively, however, both switches can be opened (for example when no defined voltage value is applied to the input connection IN).

For example, the computer port (signal line) mentioned at the outset can be connected to the input connection IN, so that the level shifter can be controlled by means of said signal line.

Fig. 2 shows one possible implementation for the mentioned complementary switching operation. For this purpose, the first switch S1 is configured as a first transistor and the second switch S2 is configured as a second transistor, the first and second transistors being complementary to each other. For example, bipolar transistors may be involved, wherein the first transistor S1 is a pnp (or npn) transistor and the second transistor S2 is correspondingly an npn (or pnp) transistor. Of course, the bipolar transistors shown can also be replaced by field effect transistors.

In the embodiment of fig. 2, the level shifter further comprises a steering circuit 200 that assumes the steering of the first switch S1 and the second switch S2. The control circuit 200 comprises an input for the input connection IN and at least two outputs, one of which is coupled to the control connection (base of the bipolar transistor) of the first switch S1 and the second of which is coupled to the control connection (base of the bipolar transistor) of the second switch S2.

In addition, the manipulation circuit 200 includes a third switch S3 and a fourth switch S4. The third switch S3 and the fourth switch S4 respectively include a control connection terminal electrically connected to the input connection terminal IN. IN addition, the third switch S3 is connected between the input connection IN and the control connection of the first switch S1. IN a similar manner, the fourth switch S4 is connected between the input connection IN and the control connection of the second switch S2.

The control circuit 200 likewise comprises a reference voltage unit 220, which supplies a voltage value to the control connection of the third switch S3 and to the control connection of the fourth switch S4, to be precise for the case IN which no defined level value is applied to the input connection IN. The reference voltage unit 220 is, for example, a voltage divider which converts a third voltage value (for example 3.3V) to a predetermined voltage value, which is selected such that, with the input connection IN high impedance, both the third switch S3 and the fourth switch S4 are open, and a third level value is applied to both control connections of the first and second switches S1, S2, such that the first and second switches are open.

Finally, the level shifter in fig. 2 comprises a total of eight resistors which may be arranged, for example, as follows. A first resistor R1 is disposed between the control connection of the first switch S1 and the third switch S3 (e.g., on the source connection or drain connection of the exemplary transistor). A second resistor R2 is disposed between the control connection of the second switch S2 and the fourth switch S4 (e.g., on the source connection or drain connection of the exemplary transistor). A third resistor R3 is arranged between the first voltage connection 110 and the control connection of the first switch S1. A fourth resistor R4 is connected between the second voltage connection 120 and the control connection of the second switch S2. The fifth resistor R5 is connected between the input connection IN and the control connection of the third switch S3 or of the fourth switch S4. A sixth resistor R6 and a seventh resistor R7 are part of the voltage divider in the exemplary reference voltage unit 220 and are connected in series between the third voltage connection 130 and the fourth voltage connection 140, wherein a current path to the control connections of the third switch S3 and the fourth switch S4 is formed between the sixth resistor R6 and the seventh resistor R7. Between the first switch S1 and the second switch S2 (for example between the first switch S1 and the output connection OUT), an eighth resistor R8 is optionally arranged. For example, IN the case of a switching operation at the input connection IN (LOW to HIGH or vice versa), the eighth resistor R8 limits the current flow between the first voltage connection 110 and the second voltage connection 120.

In the embodiment of fig. 2, all switches, that is to say the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 are formed by transistors (bipolar transistors or field effect transistors) by way of example, wherein not only the first transistor S1 is complementary to the second transistor S2, but also the third transistor S3 is complementary to the fourth transistor S4.

Fig. 3 shows another embodiment of a level shifter, wherein the embodiment differs only in that: an optional diode D1 is provided between the eighth resistor R8 and the output connection OUT, which diode prevents or at least limits the current that may flow from the output connection OUT to the first voltage connection 110. In other respects, all further elements are constructed in the same way as in fig. 2, so that a repeated description is not necessary.

Fig. 4 shows a further exemplary embodiment of a level shifter having two output connections OUT1, OUT2, wherein a first switch S1 switches a first current path between the first voltage connection 110 and one of the output connections OUT 1. The second switch S2 switches the second current path between the second voltage connection 120 and the other OUT2 of the output connections. However, the switching operation is further carried OUT such that at least one of the output connections OUT1, OUT2 is always switched to a high impedance. All further elements are constructed in the same way as in the previous embodiments. In particular, an eighth resistor R8 or a diode D1 may be provided again along the first current path and/or along the second current path (for example between the first/second switch S1, S2 and the respective output terminal OUT1/OUT 2). The aforementioned configuration results from the simple connection of the two output connections OUT1 and OUT 2.

A voltage value of about 5V may be applied across the first voltage source 110 as described above. However, higher voltage values (in principle arbitrary voltage values) can also be applied there. Thus, for example, a voltage value of about 10V, 20V or 32V may be applied thereto. A reference voltage (for example ground) is applied to the second voltage connection 120 and to the fourth voltage connection 140, for example, and an exemplary voltage value of 3.3V is applied to the third voltage connection 130. Due to the voltage divider, for example, dividing the voltage value of 3.3V into voltage values of 1.65V results in: when the input connection IN is open or a voltage value of approximately 1.65V is likewise applied there, both the third switch S3 and the fourth switch S4 are open, and the output connection OUT is therefore high-impedance. Depending on the transistors used for the switches S1,. ·, S4, an on-off action is achieved for certain level values. The first level value may be defined by: 0V (ground) is applied to the input connection up to a first high voltage value (for example 1.2V). Between the first voltage value and the second voltage value (for example 2V), the output connection OUT is high-resistive, and above the second voltage value (for example 2V), the output connection OUT is placed at ground.

The resistance may be selected, for example, as follows. The first resistor R1 may have a value of 21.5k Ω, the second resistor R2 may have a value of 4.64k Ω, the third, fourth and fifth resistors R3, R4, R5 may have resistance values of 10k Ω, respectively, the sixth and seventh resistors R6, R7 may have a value of 4.64k Ω, respectively, and the eighth resistor has a value of 464 Ω. These values are to be understood as exemplary only and may be selected differently than this in other embodiments.

The values of the resistors and voltages mentioned are to be understood as exemplary only and can be adjusted accordingly to any other value. All the values mentioned may in particular include a tolerance range of ± 3% or ± 10% or ± 50%.

The following ranges can be adjusted by means of resistors depending on the transistors used: in this range, three states are adopted by the level shifter. For example, a voltage value of 0V to 3.3V can be used at the input connection IN order to switch between the three desired states. As described, in the voltage range between 1.2V and 2V, the third and fourth switches S3, S4 may be opened, so that the first and second switches S1, S2 are also opened and no defined voltage value is applied to the output connection OUT (the state is open). If a voltage value of approximately 0V (ground) or less than 1.2V is applied to the input connection IN, for example, the third switch S3 can be closed and the fourth switch S4 (since the two switches are complementary to one another) opened, which results IN: the first switch S1 is closed and the second switch is opened, so that the voltage value V + of the first voltage connection 110 is applied to the output connection OUT. If a voltage value greater than 2V or approximately 3.3V is applied to the input connection IN, the third switch S3 is opened and the fourth switch S4 is closed, which results IN the second switch S2 being closed (and the first switch S1 being opened), which results IN the ground potential of the second voltage source 120 being applied to the output connection OUT.

The mentioned functions can also be summarized as follows:

1. if the input connection IN is disconnected, or if a computer port is connected to the input, the switches S1 to S4 are non-conductive and the output OUT is high impedance.

2. If the input connection IN is connected to ground (or to the reference potential GND or LOW), the switches S1 and S3 are switched on and the output OUT is at the first voltage value + V of the first voltage connection 110 (minus the saturation voltage of the first switch S1 and of the diode D1, if present).

3. If the voltage is increased (for example to HIGH) at the input connection IN and to a voltage greater than +0.8V at R6/R7, the switches S2 and S4 are switched on and the output connection OUT is at the saturation voltage of the second switch S2.

The diode D1 is used only as a short-circuit protection if a higher voltage is to be applied to the output connection OUT than to the first voltage connection 110 (i.e., + V). The eighth resistor R8 serves to limit cross leakage currents which may exist IN the case of switching between a high voltage level and a low voltage level at the input connection IN.

The features of the invention disclosed in the description, the claims and the drawings may be essential for the invention both individually and in any combination.

List of reference numerals

110. 120, … voltage connection terminal

S1, S2, … switch

R1, R2, … resistor

D1 diode

IN input connection

One or more output connections OUT, OUT1, …

200 control circuit

220 reference voltage unit