Voltage measurement system

Abstract

To suppress the voltage supplied to a second circuit unit from varying.SOLUTION: A circuit unit includes a first circuit unit 71 which is supplied with a first voltage as the voltage based on a reference voltage and a second circuit unit 72 which is supplied with a second voltage as the voltage based on a reference voltage the accuracy of which is higher than for the first circuit unit 71, and has a first high-potential wiring 25 and a first low-potential wiring 27 for supplying the first voltage to the first circuit unit 71 and connected so as to sandwich the first circuit unit 71, and a second high-potential wiring 26 and a second low-potential wiring 28 for supplying the second voltage to the second circuit unit 72 and connected so as to sandwich the second circuit unit 72. The first high-potential wiring 25 and the second high-potential wiring 26 are separated, and the first low-potential wiring 27 and the second low-potential wiring 28 are separated.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a voltage measurement system. [Background technology]

[0002] Conventionally, voltage measurement systems have been proposed that supply a voltage generated by a reference power supply circuit to another circuit (see, for example, Non-Patent Document 1). For example, in this voltage measurement system, a configuration has been proposed in which the voltage generated by the reference power supply circuit is supplied to an ADC (short for Analog Digital Converter) as a circuit. The ADC includes a first circuit having a resistive voltage divider circuit to which a DC current is supplied, and a second circuit having a DAC to which an AC current is supplied, and the second circuit has a function for performing calculations. In this voltage measurement system, the reference power supply circuit and the first and second circuit of the ADC are connected by a common wiring. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] REF62xx High-Precision Voltage Reference with Integrated ADC Drive Buffer, Texas Instruments, September 2016 Summary of the Invention [Problem to be solved by the invention]

[0004] However, linearity, an important characteristic of an ADC, is easily affected by errors in the voltage supplied to the second circuit section (i.e., the DAC), and accuracy decreases when the voltage supplied to the second circuit section changes. For this reason, it is desirable for a voltage with higher accuracy than the voltage supplied to the first circuit section to be supplied to the second circuit section of the ADC.

[0005] However, in the voltage measurement system described above, the reference power supply circuit and the first and second circuit sections of the ADC are connected by a common wiring. Therefore, in the voltage measurement system described above, wiring resistance drop (i.e., voltage drop) caused by the DC current supplied to the first circuit section can cause an error in the voltage supplied to the second circuit section, which uses an AC current as a load. In this case, it is possible to perform a correction to reduce the effect of the wiring resistance drop by conducting a test or the like in advance, but this correction becomes difficult if the DC current changes after the test.

[0006] An object of the present disclosure is to provide a voltage measurement system that can suppress changes in the voltage supplied to a second circuit section. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, a voltage measurement system comprises a reference power supply circuit unit (10) that generates a reference voltage and a circuit unit (70) to which a voltage based on the reference voltage is applied, the circuit unit including a first circuit unit (71) to which a first voltage based on the reference voltage is supplied, and a second circuit unit (72) to which a second voltage based on a reference voltage with higher accuracy than the first circuit unit is supplied, the voltage measurement system having a first high potential side wiring (25) and a first low potential side wiring (27) connected to sandwich the first circuit unit and supplying the first voltage to the first circuit unit, and a second high potential side wiring (26) and a second low potential side wiring (28) connected to sandwich the second circuit unit and supplying the second voltage to the second circuit unit, the first high potential side wiring and the second high potential side wiring being separated, and the first low potential side wiring and the second low potential side wiring being separated.

[0008] According to this, the first high potential side wiring and the second high potential side wiring are arranged separately, and the first low potential side wiring and the second low potential side wiring are arranged separately, so that the second circuit unit is supplied with a second voltage that reduces the influence of wiring drop on the current flowing through the first circuit unit, and it is possible to suppress the second voltage supplied to the second circuit unit from changing due to the current flowing through the first circuit unit.

[0009] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing a voltage measurement system according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram of the ADC shown in FIG. 1. [Figure 3] FIG. 10 is a schematic diagram showing a voltage measurement system according to a second embodiment. [Figure 4] FIG. 10 is a schematic diagram showing a voltage measurement system according to a third embodiment. [Figure 5] FIG. 10 is a schematic diagram showing a voltage measurement system according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, identical or equivalent parts will be denoted by the same reference numerals.

[0012] (First embodiment) A first embodiment will be described with reference to the drawings. As shown in Fig. 1, the voltage measurement system of this embodiment includes a reference power supply circuit unit 10, first to fourth terminals 31 to 34, first and second capacitance terminals 41 and 42, a capacitor 50, an ADC 70, and the like. Note that the voltage measurement system of this embodiment is configured, for example, such that the reference power supply circuit unit 10, the first to fourth terminals 31 to 34, and the ADC 70 are arranged on a common IC chip, and the first capacitance terminal 41, the second capacitance terminal 42, and the capacitor 50 are arranged as separate components from the IC chip on a wiring board on which the IC chip is mounted. IC stands for Integrated Circuit.

[0013] The reference power supply circuit section 10 of this embodiment is configured to include a reference voltage generating circuit section 11, an operational amplifier 12, a control element 13, a first resistor 15, a second resistor 16, and the like.

[0014] In the reference voltage generating circuit unit 11, a first wiring 21 and a second wiring 22 are connected, and a potential difference between the first wiring 21 and the second wiring 22 is V ref The first wiring 21 is connected to the negative input terminal 12a of the operational amplifier 12, and the second wiring 22 is connected to a third terminal 33, which will be described later. In this embodiment, the second wiring 22 includes a wiring portion that is arranged inside the reference power supply circuit unit 10 and connected to the reference voltage generation circuit unit 11, and a wiring portion that is connected to this wiring portion and is arranged outside the reference power supply circuit unit 10 and connected to the third terminal 33, which will be described later.

[0015] In this embodiment, the control element 13 is configured by a p-channel transistor or the like, and has a source terminal connected to the internal power supply 14 and a gate terminal connected to the output terminal 12 c of the operational amplifier 12 .

[0016] The first resistor 15 and the second resistor 16 are connected in series between the drain terminal side of the control element 13 and the second wiring 22. A third wiring 23, which is connected to the positive input terminal 12b of the operational amplifier 12, is connected between the first resistor 15 and the second resistor 16. A fourth wiring 24 and a fifth wiring 25 are connected between the control element 13 and the second resistor 16. The fourth wiring 24 includes a portion of wiring arranged within the reference power supply circuit unit 10 and a portion of wiring connected to this portion and connected to a first terminal 31, which will be described later. The fifth wiring 25 includes a portion of wiring arranged within the reference power supply circuit unit 10 and a portion of wiring connected to this portion and connected to a first circuit unit 71 of the ADC 70, which will be described later.

[0017] As described above, the operational amplifier 12 has the negative input terminal 12a connected to the first wiring 21, the positive input terminal 12b connected to the third wiring 23, and the output terminal 12c connected to the gate terminal of the control element 13.

[0018] The first to fourth terminals 31 to 34 are arranged, for example, on the outer edge side of an IC chip on which the reference power supply circuit unit 10 and the ADC 70 are mounted. The first terminal 31 is connected to a fourth wiring 24 that is connected between the control element 13 and the second resistor 16. The second terminal 32 is connected to a second circuit unit 72 of the ADC 70, which will be described later, via a sixth wiring 26.

[0019] The third terminal 33 is connected to the second wiring 22. The fourth terminal 34 is connected to a seventh wiring 27 connected to a first circuit unit 71 of the ADC 70 described later, and is also connected to an eighth wiring 28 connected to a second circuit unit 72 of the ADC 70 described later.

[0020] The first and second capacitance terminals 41, 42 are arranged on a wiring substrate, for example, separately from an IC chip on which the reference power supply circuit unit 10 and the ADC 70 are mounted. The first capacitance terminal 41 is connected to the first terminal 31 and the second terminal 32 via bonding wires 81, 82. The second capacitance terminal 42 is connected to the third terminal 33 and the fourth terminal 34 via bonding wires 83, 84, and is also connected to ground 43. In this embodiment, ground 43 corresponds to the reference potential source. In this embodiment, an example is described in which the reference potential source is ground 43, but the reference potential source does not have to be ground 43 as long as it is maintained at a predetermined potential.

[0021] The capacitor 50 is disposed between the first external wiring 61 connected to the first capacitance terminal 41 and the second external wiring 62 connected to the second capacitance terminal 42. As described above, the capacitor 50 in this embodiment is disposed as a separate member from the IC chip on which the reference power supply circuit unit 10 and the ADC 70 are mounted, and therefore can also be said to be an external capacitor. In this embodiment, the capacitor 50 corresponds to a capacitance unit.

[0022] 2, the ADC 70 in this embodiment includes a first circuit section 71, a second circuit section 72, an internal circuit section 73, a first internal wiring 74, a second internal wiring 75, etc., and generates a digital signal based on an analog signal input from the outside and an output signal from the second circuit section 72. In this embodiment, the ADC 70 corresponds to the circuit section.

[0023] In this embodiment, the first circuit section 71 is configured to include a resistance voltage dividing circuit section in which a first internal resistor 711 and a second internal resistor 712 are connected in series within a first internal wiring 74. In the first circuit section 71 of this embodiment, the midpoint between the first internal resistor 711 and the second internal resistor 712 is connected to an internal circuit section 73, and a reference power supply for driving the internal circuit section 73 is generated. The internal circuit section 73 is configured to include an operational amplifier and the like that performs predetermined processing within the ADC 70.

[0024] The second circuit unit 72 is configured to include a DAC 720, and is a part that configures a function for performing calculations, and is connected to the second internal wiring 75 via a first switch 721 and a second switch 722. In this embodiment, the calculation unit is configured to include the DAC 720.

[0025] The first internal wiring 74 and the second internal wiring 75 are arranged separately within the ADC 70. One end of the first internal wiring 74 is connected to the fifth wiring 25 and the other end is connected to the seventh wiring 27, and a DC current flows from the fifth wiring 25 to the seventh wiring 27, thereby supplying a voltage generated by the reference power supply circuit unit 10 (e.g., 5 V) and a voltage resulting from a change in the DC voltage. The second internal wiring 75 is connected to the sixth wiring 26 and the other end is connected to the eighth wiring 28. The on / off of the first switch 721 and the second switch 722 is appropriately controlled, causing an instantaneous current to flow from the capacitor 50 to the eighth wiring 28 via the sixth wiring 26, thereby supplying a voltage resulting from a change in the AC voltage and a voltage generated by the reference power supply circuit unit 10 (e.g., 5 V). In this embodiment, the steady DC voltage supplied to the first circuit section 71 corresponds to the first voltage, and the instantaneous AC voltage added to the DC voltage supplied to the second circuit section 72 corresponds to the second voltage.

[0026] The above is the configuration of the voltage measurement system in this embodiment. In this embodiment, the fifth wiring 25 corresponds to the first high-potential side wiring, and the sixth wiring 26 corresponds to the second high-potential side wiring. In this embodiment, the seventh wiring 27 corresponds to the first low-potential side wiring, and the eighth wiring 28 corresponds to the second low-potential side wiring. In this voltage measurement system, as described above, a DC current flows through the first circuit unit 71, and an instantaneous AC current flows through the second circuit unit 72 depending on the on / off states of the first switch 721 and the second switch 722. In this case, the second circuit unit 72 (i.e., the DAC 720) performs functions necessary for calculations, and it is desirable that a highly accurate voltage be supplied. Therefore, in this embodiment, as described above, the fifth wiring 25 and the seventh wiring 27 through which a DC current flows are arranged separately from the sixth wiring 26 and the eighth wiring 28 through which an AC current flows. In other words, the path through which the DC current flows and the path through which the AC current flows are separated. Therefore, the voltage supplied to the second circuit section 72 can be prevented from being changed by the DC current supplied to the first circuit section 71.

[0027] 1, the connection point between the first resistor 15 and the second wiring 22 is referred to as a first node N1, the connection point between the control element 13 and the second resistor 16 and the fourth wiring 24 is referred to as a second node N2, and the connection point between the control element 13 and the second resistor 16 and the fifth wiring 25 is referred to as a third node N3. In the following description, the current flowing from the first node N1 to the third terminal 33 side is referred to as I vref The current I flowing from the first node N1 to the third terminal 33 side is vref includes the current flowing via the control element 13 and the current flowing from the reference voltage generating circuit unit 11. In the following description, the resistance value of the first resistor 15 is defined as R1, and the resistance value of the second resistor 16 is defined as R2. The wiring resistance of the portion of the second wiring 22 located between the first node N1 and the third terminal 33 is defined as R vrefgnd The wiring resistance of the fifth wiring 25 is R dc The wiring resistance of the seventh wiring 27 is R dc、vrefgnd In the following description, the current flowing from the fifth wiring 25 to the seventh wiring 27 via the ADC 70 is referred to as I dc In this embodiment, as described above, the AC current is an instantaneous current that flows from the capacitor 50 to the sixth wiring 26 and the eighth wiring 28. For this reason, it is assumed that the influence of the wiring resistance of the sixth wiring 26 and the eighth wiring 28 through which the AC current flows and the influence of the wiring drop caused by the AC current can be ignored.

[0028] In this case, the potential of the first node N1 is determined by the wiring resistance of the second wiring 22 being R vrefgnd and the current flowing through the second wiring 22 is I vref Therefore, I vref ×R vrefgnd If the potential of the second node N2 and the third node N3 is V, the potential V is expressed by the following equation 1 with the first node N1 as the reference.

[0029]

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[0030]

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[0031]

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[0032] According to the present embodiment described above, the fifth wiring 25 and the seventh wiring 27 connected to the first circuit portion 71 and the sixth wiring 26 and the eighth wiring 28 connected to the second circuit portion 72 are arranged separately. Therefore, a voltage that reduces the influence of wiring drop on the current flowing through the first circuit portion 71 is supplied to the second circuit portion 72, and it is possible to suppress the voltage supplied to the second circuit portion 72 from changing due to the current flowing through the first circuit portion 71.

[0033] (1) In this embodiment, the first to fourth terminals 31 to 34 and the first and second capacitance terminals 41, 42 are provided, and the capacitor 50 is connected to the second circuit unit 72 via the first to fourth terminals 31 to 34 and the first and second capacitance terminals 41, 42. This improves the flexibility to select the size and placement space of the capacitor 50 compared to when the capacitor 50 is placed inside an IC chip. Furthermore, in this embodiment, the fifth wiring 25 and the sixth wiring 26 are separated, and the seventh wiring 27 and the eighth wiring 28 are also separated, so that the wiring to the second circuit unit 72 that draws AC current is directly connected to the capacitor 50 (i.e., capacitance). This allows the capacitor 50 to instantaneously supply current in response to voltage fluctuations caused by AC current, further suppressing voltage fluctuations.

[0034] (2) In this embodiment, the reference power supply circuit unit 10 and the first circuit unit 71 of the ADC 70 are connected via the fifth wiring 25, and no terminals or the like are provided. When the reference power supply circuit unit 10 and the ADC 70 are provided on a common IC chip as in this embodiment, the reference power supply circuit unit 10 and the ADC 70 are generally provided in the approximate center of the IC chip. Furthermore, the reference power supply circuit unit 10 and the ADC 70 are provided closer to each other than to each other than the first to fourth terminals 31 to 34. This makes it easier to shorten the length of the fifth wiring 25. Furthermore, in such a voltage measurement system, wiring is densely arranged near the first to fourth terminals 31 to 34. Therefore, by directly connecting the reference power supply circuit unit 10 and the first circuit unit 71 of the ADC 70 via the fifth wiring 25, it is easier to secure layout space.

[0035] (Second embodiment) A second embodiment will be described. This embodiment differs from the first embodiment in that it includes a plurality of ADCs 70. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0036] The voltage measurement system of this embodiment is provided with two ADCs 70, as shown in Fig. 3. In the following description, one ADC 70 is referred to as a first ADC 70a, and the other ADC 70 is referred to as a second ADC 70b. Note that the first ADC 70a and the second ADC 70b each have the same configuration as the ADC 70 described in the first embodiment.

[0037] Two sixth wires 26 are connected to the second terminal 32. One sixth wire 26 is connected to the second circuit section 72 in the first ADC 70a, and the other sixth wire 26 is connected to the second circuit section 72 in the second ADC 70b. Two seventh wires 27 are connected to the fourth terminal 34. One seventh wire 27 is connected to the first circuit section 71 in the first ADC 70a, and the other seventh wire 27 is connected to the first circuit section 71 in the second ADC 70b. Two eighth wires 28 are connected to the fourth terminal 34. One eighth wire 28 is connected to the second circuit section 72 in the first ADC 70a, and the other eighth wire 28 is connected to the second circuit section 72 in the second ADC 70b.

[0038] In addition, in this embodiment, the fifth wiring 25 is divided into two on the IC chip, and one of the fifth wirings 25 is connected to the first circuit section 71 in the first ADC 70a, and the other fifth wiring 25 is connected to the first circuit section 71 in the second ADC 70b.

[0039] The above is the configuration of the voltage measurement system in this embodiment. Since this voltage measurement system includes a plurality of ADCs 70, the voltage supplied to the first circuit section 71 is expressed by the following equation 4.

[0040]

number

[0041] According to the present embodiment described above, the fifth wiring 25 and the seventh wiring 27 connected to the first circuit portion 71 and the sixth wiring 26 and the eighth wiring 28 connected to the second circuit portion 72 are arranged separately. Therefore, the same effects as those of the first embodiment can be obtained.

[0042] (1) In this embodiment, multiple ADCs 70 are provided, but the fifth wiring 25 and seventh wiring 27 connected to the first circuit unit 71 and the sixth wiring 26 and eighth wiring 28 connected to the second circuit unit 72 are arranged separately. Therefore, even if the number of ADCs 70 operating on the system changes, it is possible to prevent the voltage supplied to the second circuit unit 72 from changing due to the current flowing through the first circuit unit 71.

[0043] (Third embodiment) A third embodiment will now be described. This embodiment is different from the first embodiment in that the configuration of the reference power supply circuit section 10 is changed. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0044] 4, the reference power supply circuit 10 includes a constant current source 17 and a Zener diode 18 instead of the reference voltage generation circuit 11. Specifically, the Zener diode 18 has a cathode connected to the constant current source 17 and an anode connected to the second wiring 22. The first wiring 21 is connected between the constant current source 17 and the Zener diode 18.

[0045] According to the present embodiment described above, the fifth wiring 25 and the seventh wiring 27 connected to the first circuit portion 71 and the sixth wiring 26 and the eighth wiring 28 connected to the second circuit portion 72 are arranged separately. Therefore, it is possible to obtain the same effects as in the first embodiment.

[0046] (1) In this embodiment, the reference voltage V ref is generated according to the breakdown voltage of the Zener diode 18. Therefore, a highly accurate reference voltage V ref It becomes easier to generate the reference voltage V ref This can suppress variations in the

[0047] (Fourth embodiment) A fourth embodiment will be described. This embodiment is different from the first embodiment in that the connection location of the eighth wiring 28 is changed. As the rest is the same as the first embodiment, a description thereof will be omitted here.

[0048] 5, the eighth wiring 28 is arranged to connect the second circuit section 72 of the ADC 70 to the first node N1 of the second wiring 22 and the third terminal 33. For this reason, if the connection point between the eighth wiring 28 and the second wiring 22 is defined as the fourth node N4, the potential on the low potential side of the second circuit section 30 becomes close to the potential of the first node N1. Therefore, for example, if the potential of the fourth node N4 is the same as the potential of the first node N1, the voltage applied to the second circuit section 72 is expressed by the following equation 5.

[0049]

number

[0050] According to the present embodiment described above, the fifth wiring 25 and the seventh wiring 27 connected to the first circuit portion 71 and the sixth wiring 26 and the eighth wiring 28 connected to the second circuit portion 72 are arranged separately. Therefore, the same effects as those of the first embodiment can be obtained.

[0051] (1) In this embodiment, the eighth wiring 28 is arranged to connect the second circuit unit 72 of the ADC 70 to the first node N1 and the third terminal 33 of the second wiring 22. Therefore, the current I vref The influence of

[0052] (Other embodiments) Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0053] In the above embodiments, the first voltage is a steady DC voltage and the second voltage is an instantaneous AC voltage added to the DC voltage. However, depending on the circuit configuration, the first voltage and the second voltage may both be steady DC voltages or may both be instantaneous AC voltages added to the DC voltage.

[0054] In the above embodiments, the ADC 70 including the first circuit unit 71 and the second circuit unit 72 has been described as an example. However, other configurations can be changed as appropriate as long as the ADC 70 includes the first circuit unit 71 and the second circuit unit 72 that needs to be supplied with a voltage with higher accuracy than the first circuit unit 71. For example, instead of the ADC 70, a separate component including the first circuit unit 71 and the second circuit unit 72 may be provided, or the first circuit unit 71 and the second circuit unit 72 may each be included in a separate component.

[0055] Furthermore, in each of the above embodiments, the capacitor 50 may be arranged on an IC chip together with the reference power supply circuit section 10 and the ADC 70. In this configuration, since the capacitor 50 is also arranged on the IC chip, the first to fourth terminals 31 to 34 and the first and second capacitance terminals 41, 42 may not be provided.

[0056] The above embodiments can also be combined as appropriate. For example, the above two embodiments may be combined with the third and fourth embodiments, thereby providing a plurality of ADCs 70. Furthermore, the third embodiment may be combined with the fourth embodiment, thereby providing a constant current source 17 and a Zener diode 18 instead of the reference voltage generating circuit unit 11.

[0057] [Disclosure of the Invention] The present disclosure described above can be understood from the following viewpoints, for example. [First viewpoint] 1. A voltage measurement system comprising: a reference power supply circuit unit (10) that generates a reference voltage; a circuit section (70) to which a voltage based on the reference voltage is applied, The circuit unit includes a first circuit unit (71) to which a first voltage is supplied as a voltage based on the reference voltage, and a second circuit unit (72) to which a second voltage is supplied as a voltage based on the reference voltage and has higher accuracy than the first circuit unit, a first high potential side wiring (25) and a first low potential side wiring (27) connected to sandwich the first circuit unit and supplying the first voltage to the first circuit unit; a second high potential side wiring (26) and a second low potential side wiring (28) connected to sandwich the second circuit unit and supplying the second voltage to the second circuit unit, the first high potential side wiring and the second high potential side wiring are separated, A voltage measurement system in which the first low potential side wiring and the second low potential side wiring are separated. [Second viewpoint] the circuit unit is an ADC having the first circuit unit and the second circuit unit, the first circuit section includes a resistive voltage divider circuit, The voltage measurement system according to the first aspect, wherein the second circuit section is configured to include a calculation section. [Third Perspective] The voltage measurement system according to the second aspect, wherein a plurality of the ADCs are provided. [Fourth viewpoint] The voltage measurement system according to any one of the first to third aspects, wherein the reference power supply circuit section includes a Zener diode (18), and generates the reference voltage based on a breakdown voltage of the Zener diode. [Fifth viewpoint] A first capacitance terminal (41), a second capacitance terminal (42) connected to a reference potential source (43); a capacitance section (50) disposed between the first capacitance terminal and the second capacitance terminal; a first terminal (31) connected to the reference power supply circuit unit and to the first capacitance terminal; a second terminal (32) connected to the second circuit portion via the second high potential side wiring and connected to the first capacitance terminal; a third terminal (33) connected to the reference power supply circuit unit and to the second capacitance terminal; a fourth terminal (34) connected to the first circuit portion via the first low potential side wiring and connected to the second capacitance terminal; The voltage measurement system according to any one of the first to fourth aspects, wherein the second circuit section is supplied with an AC current from the capacitance section. [Sixth viewpoint] The voltage measurement system according to a fifth aspect, wherein the second low potential side wiring is connected to the second circuit portion and also to the fourth terminal. [Seventh viewpoint] The voltage measurement system according to a fifth aspect, wherein the second low potential side wiring is connected to the second circuit section and also to a wiring (22) that connects the third terminal and the reference power supply circuit section. [Explanation of symbols]

[0058] 10 Reference power supply circuit section 25 5th wiring (1st high potential side wiring) 26 6th wiring (2nd high potential side wiring) 27 7th wiring (1st low potential side wiring) 28 8th wiring (2nd low potential side wiring) 70 ADC (circuit section) 71 1st circuit section 72 2nd circuit section

Claims

1. 1. A voltage measurement system comprising: a reference power supply circuit unit (10) that generates a reference voltage; a circuit section (70) to which a voltage based on the reference voltage is applied, The circuit unit includes a first circuit unit (71) to which a first voltage is supplied as a voltage based on the reference voltage, and a second circuit unit (72) to which a second voltage is supplied as a voltage based on the reference voltage and having higher accuracy than the first circuit unit, a first high potential side wiring (25) and a first low potential side wiring (27) connected to sandwich the first circuit unit and supplying the first voltage to the first circuit unit; a second high-potential side wiring (26) and a second low-potential side wiring (28) connected to sandwich the second circuit section and supplying the second voltage to the second circuit section, the first high potential side wiring and the second high potential side wiring are separated, A voltage measurement system in which the first low potential side wiring and the second low potential side wiring are separated.

2. the circuit unit is an ADC having the first circuit unit and the second circuit unit, the first circuit section is configured to include a resistive voltage divider circuit, The voltage measurement system according to claim 1 , wherein the second circuit section includes a calculation section.

3. The voltage measurement system according to claim 2 , wherein the ADC is provided in plural.

4. 2. The voltage measurement system according to claim 1, wherein the reference power supply circuit section includes a Zener diode (18), and generates the reference voltage based on a breakdown voltage of the Zener diode.

5. a first capacitance terminal (41); a second capacitance terminal (42) connected to a reference potential source (43); a capacitance section (50) disposed between the first capacitance terminal and the second capacitance terminal; a first terminal (31) connected to the reference power supply circuit unit and to the first capacitance terminal; a second terminal (32) connected to the second circuit portion via the second high potential side wiring and connected to the first capacitance terminal; a third terminal (33) connected to the reference power supply circuit unit and to the second capacitance terminal; a fourth terminal (34) connected to the first circuit portion via the first low potential side wiring and connected to the second capacitance terminal; 5. The voltage measurement system according to claim 1, wherein the second circuit section is supplied with an AC current from the capacitance section.

6. The voltage measurement system according to claim 5 , wherein the second low potential side wiring is connected to the second circuit section and also to the fourth terminal.

7. 6. The voltage measurement system according to claim 5, wherein the second low potential side wiring is connected to the second circuit section and also to a wiring (22) that connects the third terminal and the reference power supply circuit section.

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