Device and method for ratiometric measurement of voltages for an analog-digital-converter

Abstract

Device for ratiometric measurement of voltages for an analog-digital converter, wherein the device comprises a functional providing unit, a microcontroller and a first sensor, wherein a reference voltage is provided to the microcontroller and a first supply voltage is provided to the first sensor and the microcontroller by the functional providing unit, and wherein the first sensor is connected to the microcontroller in terms of signalling by transmitting sensor signals, and wherein the microcontroller comprises a first multiplexer and a second multiplexer, wherein the multiplexers outputs signals to the analog-digital-converter. According to the invention, it is provided that the reference voltage and the first supply voltage are in each case present on the input side at the first multiplexer and at the second multiplexer, wherein in a first switching state the first supply voltage can be measured on the output side by using the reference voltage as a reference for the analog-digital-converter and in a second switching state the reference voltage can be measured by using the first supply voltage as a reference for the analog-digital-converter.

Claims

1. Device for ratiometric measurement of voltages and monitoring of at least one voltage for an analog-digital-converter, wherein the device comprises a functional providing unit, a microcontroller and a first sensor, wherein a reference voltage is provided to the microcontroller and a first supply voltage is provided to the first sensor and the microcontroller by the functional providing unit, and wherein the first sensor is connected to the microcontroller in terms of signal Rifling by transmission of sensor signals, and wherein the microcontroller comprising a first multiplexer and a second multiplexer, wherein the multiplexers outputs signals to the analog-digital-converter, wherein: the reference voltage and the first supply voltage are connected to the input side of the first multiplexer and to the input side of the second multiplexer respectively, wherein it is possible to measure the first supply voltage on the output side in a first switching state by using the reference voltage as a reference for the analog-digital-converter and to measure the reference voltage in a second switching state by using the first supply voltage as a reference for the analog-digital-converter.

2. Device according to claim 1, wherein: the first multiplexer and the second multiplexer are arranged in parallel with one another on the input side with respect to the first supply voltage.

3. Device according to claim 1, wherein: the first multiplexer and the second multiplexer are arranged in parallel with one another on the input side with respect to the reference voltage.

4. Device according to one of claim 1, wherein: in the first switching state in the first multiplexer the reference voltage is selected as an input signal and is connected through to an output of the first multiplexer; and in the second multiplexer the first supply voltage is selected as an input signal and is connected through to an output of the second multiplexer.

5. Device according to claim 1, wherein: in the second switching state in the first multiplexer the first supply voltage is selected as an input signal and is connected through to an output of the first multiplexer; and in the second multiplexer the reference voltage is selected as an input signal and is connected through to an output of the second multiplexer.

6. Device according to claim 1, wherein: the analog-digital-converter is provided and formed to perform the measurements in the first switching state and the second switching state, and wherein the analog-digital-converter is provided and formed to detect whether in the first switching state the first supply voltage is greater than or equal to the reference voltage and whether in the second switching state the first supply voltage is greater than or equal to the reference voltage.

7. Device according to claim 1, wherein: the reference voltage is provided by a first voltage regulator and the first supply voltage is provided by a second voltage regulator, wherein the first voltage regulator is connected to the second voltage regulator in terms of signaling in such a way that a change in the reference voltage causes a change in the first supply voltage.

8. Device according to claim 1, wherein: the functional providing unit and the microcontroller are spaced apart.

9. Device according to claim 1, wherein: the analog-digital-converter outputs a ratiometric sensor value.

10. Device according to claim 1, wherein: a connection between the reference voltage and the second multiplexer is implemented on the input side of the second multiplexer at the inside or outside of the microcontroller.

11. Method for ratiometric measurement and monitoring of voltages for an analog-digital-converter, comprising the method steps: (a) providing a device according to claim 1: (b) switching the device to the first switching state and measuring the first supply voltage by using the reference voltage as a reference for the analog-digital-converter; or switching the device to the second switching state and measuring the reference voltage by using the first supply voltage as a reference for the analog-digital-converter.

Description

[0045] Further aims, advantages and usefulness of the present invention are to be taken from the following description in conjunction with the drawings.

[0046] The following figures show:

[0047] FIG. 1 a device according to the prior art;

[0048] FIG. 2 a device according to a preferred embodiment;

[0049] FIG. 3A a representation of the first switching state of the device according to FIG. 2;

[0050] FIG. 3B a representation of the second switching state of the device according to FIG. 2.

[0051] In the figures, identical components are to be understood with the corresponding reference sign in each case. For the sake of clarity, some components in the figures may not have a reference sign, but have been designated elsewhere.

[0052] FIG. 1 shows a device 1 according to the prior art, by means of which a ratiometric measurement of voltages can be performed.

[0053] The device 1 comprises a functional providing unit 3 and a microcontroller 4. At least one sensor 5 is also provided, in this case the first sensor 5. It is clear that the device 1 according to the invention is not limited to a single sensor 5.

[0054] Furthermore, the functional providing unit 3 has a first voltage regulator 10 and a second voltage regulator 11. The first voltage regulator 10 outputs a reference voltage 6 to the microcontroller 4, wherein the second voltage regulator 11 providing a supply voltage 7 to the sensor 5. The voltages are always to be understood with respect to a main conducting line 15, so that in each case the potential difference indicates the respective voltage.

[0055] The microcontroller 4 comprises a first multiplexer 8 and a second multiplexer 9, which are each connected on the output side to an analog-digital-converter 2. On the input side, the supply voltage 7 is applied to each of the multiplexers 8, 9.

[0056] Furthermore, a voltage divider 14 is provided, which is also connected to the supply voltage 7 and divides the supply voltage 7. In the present example, the supply voltage 7 has a value of 5.2 V, so that the output voltage of the voltage divider 14 is 2.6 V.

[0057] This divided voltage is applied to a first further analog-digital-converter 12 and a second further analog-digital-converter 13. Furthermore, the reference voltage 6 is applied to these further analog-digital-converters 12, 13. The outputs of the second further analog-digital-converters 12, 13 are further processed in a second processing unit 17, for example by means of software which is stored in the second processing unit 17.

[0058] In contrast to this, the device 1 according to the invention now represents a considerable improvement, since the voltage divider 14 as well as the further analog-digital-converters 12, 13 and, in addition, also the second processing unit 17 can be dispensed with, at least with respect to the ratiometric measurement and monitoring of the supply voltage 7.

[0059] According to the invention, it is provided according to FIG. 2 that a device 1 for ratiometric measurement of voltages is provided for an analog-digital-converter 2, wherein the device comprises a functional providing unit 3, a microcontroller 4 and a first sensor 5, wherein a reference voltage 6 is provided to the microcontroller 4 and a first supply voltage 7 is provided to the first sensor 5 and the microcontroller 4 by the functional providing unit 3, and wherein the first sensor 5 is connected to the microcontroller 4 by means of transmitting sensor signals, and wherein the microcontroller 4 comprises a first multiplexer 8 and a second multiplexer 9, wherein the multiplexers 8, 9 output signals to the analog-digital-converter 2. According to the invention, the reference voltage 6 and the first supply voltage 7 are applied to the input of the first multiplexer 8 and the second multiplexer 9 respectively, wherein, in a first switching state S1, the first supply voltage 7 is output by using the reference voltage 6 as a reference for the analog-digital-converter 2 and, in a second switching state S2, the supply voltage 7 is output by using the reference voltage 6 as a reference for the analog-digital-converter 2.

[0060] The circuit according to the invention can be seen in FIG. 2, the switching positions S1, S2 can be seen in FIGS. 3A and 3B and are described in more detail below.

[0061] Further according to FIG. 2, it is shown that the first multiplexer 8 and the second multiplexer 9 are arranged parallel to each other on the input side with respect to the first supply voltage 7 and that the first multiplexer 8 and the second multiplexer 9 are arranged parallel to each other on the input side with respect to the reference voltage 6. This means that both the reference voltage 6 and the supply voltage 7 form an input of the respective multiplexer 8, 9.

[0062] The analog-digital-converter 2 is provided and formed to perform the measurements in the first switching state S1 and the second switching state S2. Further preferably, the analog-digital-converter 2 is provided and formed to detect whether in the first switching state S1 the first supply voltage 7 is greater than or equal to the reference voltage 6 and whether in the second switching state S2 the first supply voltage 7 is greater than or equal to the reference voltage 6.

[0063] The respective switching states S1, S2 can be realized, for example, in such a way that in the first switching state. [0064] in the first multiplexer 8 the reference voltage 6 is selected as an input signal and is connected through to an output of the first multiplexer 8; and [0065] in the second multiplexer 9 the first supply voltage 7 is selected as an input signal and is connected through to an output of the second multiplexer 9;
and that
in the second switching state S2 [0066] in the first multiplexer 8 the first supply voltage 7 is selected as an input signal and is connected through to an output of the first multiplexer 8; and [0067] in the second multiplexer 9 the reference voltage 6 is selected as an input signal and is connected through to an output of the second multiplexer 9.

[0068] According to the invention, it can be achieved by means of the provided arrangement and by means of the switching states S1, S2 that the ratiometric measurement of the voltages and monitoring of the supply voltage 7 can be performed by a single analog-digital-converter 2. This leads to a considerably simpler switching structure and to a reduction in the number of components.

[0069] In the first switching state S1, the first supply voltage 7 can be measured on the output side by using the reference voltage 6 as a reference for the analog-digital-converter 2.

[0070] In the second switching state S2, the reference voltage 6 can be measured by using the first supply voltage 7 as a reference for the analog-digital-converter 2.

[0071] The measurements of the voltages with different references are in the present case the ratiometric measurement and monitoring of the supply voltage, only with considerably reduced constructional effort.

[0072] The values output by the analog-digital-converter 2 can be further processed by means of a first processing unit 16.

[0073] The values output are the values relating to the different measurements from the switching states S1, S2, so that ratiometric measurement and monitoring is possible by means of a single analog-digital-converter 2.

[0074] FIG. 3A shows the first switching state S1 and FIG. 3B shows the second switching state S2.

[0075] In the first switching state S1, the reference voltage 6 is selected on the input of the first multiplexer 8 and the supply voltage 7 is selected on the input of the second multiplexer 9 and accordingly connected through as an output of the respective multiplexer 8, 9, so that the corresponding output signals of the multiplexers 8, 9 are made available to the analog-digital-converter 2.

[0076] The respective selected input signals are shown by thick drawn arrows.

[0077] In the second switching state S2, the supply voltage 7 is selected on the input side of the first multiplexer 8 and the reference voltage 6 is selected on the input side of the second multiplexer 9 and accordingly connected through as an output of the respective multiplexer 8, 9, so that the corresponding output signals of the multiplexers 8, 9 are made available to the analog-digital-converter 2.

[0078] The respective selected input signals are shown by thick drawn arrows.

[0079] All features disclosed in the application documents are claimed to be essential to the invention insofar as they are individually and in combination new compared to the prior art.

LIST OF REFERENCE SIGNS

[0080] 1 Device [0081] 2 Analog-digital-converter [0082] 3 Functional providing unit [0083] 4 Microcontroller [0084] 5 First sensor [0085] 6 Reference voltage [0086] 7 Supply voltage [0087] 8 First multiplexer [0088] 9 Second multiplexer [0089] 10 First voltage regulator [0090] 11 Second voltage regulator [0091] 12 First further analog-digital-converter [0092] 13 Second further analog-digital-converter [0093] 14 Voltage divider [0094] 15 Main conducting line [0095] 16 First processing unit [0096] 17 Second processing unit [0097] S1 First switching state [0098] S2 Second switching state