A platinum resistance high-precision acquisition circuit and method

Abstract

The present invention relates to the field of platinum resistor acquisition technology, specifically disclosing a high-precision platinum resistor acquisition circuit and method. The acquisition circuit comprises: a pre-voltage divider circuit comprising a high-precision resistor and a platinum resistor, one end of the high-precision resistor being electrically connected to a power supply, the other end being electrically connected to one end of the platinum resistor, and the other end of the platinum resistor being electrically connected to ground; a drive enhancement circuit being electrically connected to the pre-voltage divider circuit; and a ΣΔADC acquisition circuit, wherein a reference voltage input terminal is electrically connected to the voltage divider of the high-precision resistor via the drive enhancement circuit, a signal input terminal is electrically connected to the voltage divider of the platinum resistor via the drive enhancement circuit, and a signal output terminal serves as the output terminal of the acquisition circuit. The present invention designs the pre-voltage divider circuit, the drive enhancement circuit, and the ΣΔADC acquisition circuit. Compared to traditional constant current source acquisition circuits, the acquisition circuit has a compact structure, uses fewer components, and has low power consumption. It supports platinum resistors ranging from 100Ω to 1kΩ, achieves a full-scale accuracy of 0.5°C, and is stable and reliable during the sampling process.

Description

Technical Field

[0001] The present invention relates to the technical field of platinum resistance acquisition, and in particular to a high-precision platinum resistance acquisition circuit and method. Background Art

[0002] Platinum resistance temperature sensor is a temperature sensor made by using a certain functional relationship between its resistance and temperature. Due to its advantages of high accuracy, large measurement range, good reproducibility and stability, it is widely used in temperature measurement in the medium temperature range (-200℃~650℃).

[0003] Temperature monitoring system designs vary depending on control system design requirements, with some employing integrated chips, others employing constant current and constant voltage devices. Because platinum RTDs offer advantages such as a wide measurement range, good stability, high reproducibility of indications, and oxidation resistance, Pt100 RTDs are often used as temperature sensing elements in temperature measurement systems for the design and implementation of temperature sensors.

[0004] The traditional acquisition circuit uses a constant current measurement circuit, which has a large circuit volume, low measurement accuracy and complex temperature compensation.

[0005] Based on this technical background, the present invention studies a high-precision acquisition circuit and method for platinum resistance. Summary of the Invention

[0006] In response to the shortcomings of the existing technology, the present invention provides a high-precision platinum resistance acquisition circuit and method. The acquisition circuit is designed with a pre-voltage divider circuit, a drive enhancement circuit and a ΣΔADC acquisition circuit. Compared with the traditional constant current source acquisition circuit, the acquisition circuit has a compact structure, uses fewer components, and has low power consumption. It supports platinum resistances from 100Ω to 1kΩ, has a full-scale accuracy of 0.5°C, and is stable and reliable during the sampling process.

[0007] In order to achieve the above-mentioned object, the first aspect of the present invention provides a platinum resistance high-precision acquisition circuit, comprising:

[0008] A pre-voltage divider circuit includes a high-precision resistor and a platinum resistor, wherein one end of the high-precision resistor is electrically connected to a power supply, and the other end is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground;

[0009] a driving enhancement circuit, electrically connected to the pre-voltage divider circuit, for enhancing the driving capability of the pre-voltage divider circuit;

[0010] The ΣΔADC acquisition circuit has a reference voltage input terminal electrically connected to the voltage divider of the high-precision resistor via the drive enhancement circuit, a signal input terminal electrically connected to the voltage divider of the platinum resistor via the drive enhancement circuit, and a signal output terminal serving as the output terminal of the acquisition circuit.

[0011] A second aspect of the present invention provides a high-precision platinum resistance acquisition method performed in the above acquisition circuit, comprising:

[0012] One end of the high-precision resistor is electrically connected to the power supply, and the other end is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground to form a pre-voltage divider circuit;

[0013] The divided voltage of the high-precision resistor is driven and enhanced as a reference voltage of the ΣΔADC acquisition circuit;

[0014] The signal input end of the ΣΔADC acquisition circuit is used to acquire the divided voltage of the driven enhanced platinum resistor.

[0015] The beneficial effects of the present invention include:

[0016] (1) The high-precision platinum resistance acquisition circuit proposed in the present invention is designed with a pre-voltage divider circuit, a drive enhancement circuit and a ΣΔADC acquisition circuit. Compared with the traditional constant current source acquisition circuit, the acquisition circuit has a compact structure, uses fewer components, and has low power consumption. It supports platinum resistances from 100Ω to 1kΩ, and the full-scale accuracy can reach 0.5°C. It is stable and reliable during the sampling process.

[0017] (2) The high-precision platinum resistor acquisition circuit proposed in the present invention only requires a constant voltage source for power supply, and does not require a precise constant current source, which is simple and easy to implement. The voltage obtained by the high-precision resistor in the voltage divider circuit is used as the reference voltage of the ΣΔADC acquisition circuit after passing through the driving enhancement circuit; the measured platinum resistor divided voltage is used as the acquisition signal input of the ΣΔADC acquisition circuit after passing through the driving enhancement circuit.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the structure of the platinum resistance high-precision acquisition circuit proposed in the present invention.

[0021] Description of reference numerals:

[0022] 1-Pre-voltage divider circuit, 2-Drive enhancement circuit, 3-ΣΔADC acquisition circuit;

[0023] REF-reference voltage input terminal, ADC_IN-signal input terminal. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0025] The present invention provides a platinum resistance high-precision acquisition circuit, such as Figure 1 As shown, including:

[0026] A pre-voltage divider circuit 1 includes a high-precision resistor and a platinum resistor, one end of the high-precision resistor is electrically connected to the power supply, the other end of the high-precision resistor is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground;

[0027] The driving enhancement circuit 2 is electrically connected to the pre-voltage divider circuit 1 and is used to enhance the driving capability of the pre-voltage divider circuit 1;

[0028] ΣΔADC acquisition circuit 3, the reference voltage input terminal REF is electrically connected to the voltage divider of the high-precision resistor through the drive enhancement circuit 2, the signal input terminal ADC_IN is electrically connected to the voltage divider of the platinum resistor through the drive enhancement circuit 2, and the signal output terminal serves as the output terminal of the acquisition circuit.

[0029] In the present invention, a pre-voltage divider circuit, a drive enhancement circuit and a ΣΔADC acquisition circuit are designed. Compared with the traditional constant current source acquisition circuit, the acquisition circuit has a compact structure, uses fewer components, has low power consumption, supports platinum resistors from 100Ω to 1kΩ, has a full-scale accuracy of 0.5°C, and is stable and reliable during the sampling process.

[0030] According to the present invention, the precision of the high-precision resistor is 0.05%;

[0031] The platinum resistance is a type of platinum resistance ranging from PT100Ω to PT1000.

[0032] According to the present invention, the acquisition circuit is compatible with 2-wire, 3-wire and 4-wire sensor connections.

[0033] According to the present invention, the acquisition circuit has an overvoltage protection function.

[0034] According to the present invention, the full-scale accuracy of the acquisition circuit is 0.5°C.

[0035] Preferably, the acquisition circuit has open circuit, short circuit and over-range fault detection functions.

[0036] According to the present invention, the reference voltage input terminal REF is a pair of differential input terminals, and the input voltage of the pair of differential input terminals is the voltage across the high-precision resistor.

[0037] According to the present invention, the signal input terminal ADC_IN is a pair of differential input terminals, and the voltage collected by the pair of differential input terminals is the voltage across the platinum resistor.

[0038] In the present invention, the pre-voltage divider circuit only needs to be powered by a constant voltage source, and does not require a precision constant current source, which is simple and easy to implement. The voltage obtained by the high-precision resistor in the voltage divider circuit is used as the reference voltage of the ΣΔADC acquisition circuit after passing through the drive enhancement circuit; the measured platinum resistor divided voltage is used as the acquisition signal input of the ΣΔADC acquisition circuit after passing through the drive enhancement circuit.

[0039] The present invention also provides a high-precision platinum resistance acquisition method performed in the above acquisition circuit, comprising:

[0040] One end of the high-precision resistor is electrically connected to the power supply, the other end is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground to form a pre-voltage divider circuit 1;

[0041] The divided voltage of the high-precision resistor is used as the reference voltage of the ΣΔADC acquisition circuit 3 after being driven and enhanced;

[0042] The signal input terminal ADC_IN of the ΣΔADC acquisition circuit 3 is used to acquire the divided voltage of the driven enhanced platinum resistor.

[0043] According to the present invention, the voltage divided by the high-precision resistor is used as the reference voltage of the ΣΔADC acquisition circuit 3 after being driven and enhanced, including:

[0044] The voltage across the high-precision resistor is driven and enhanced to serve as a pair of differential reference voltages for the ΣΔADC acquisition circuit 3;

[0045] The signal input terminal ADC_IN of the ΣΔADC acquisition circuit 3 is used to collect the divided voltage of the driven enhanced platinum resistor, including:

[0046] The voltage across the driven enhanced platinum resistor is collected using a pair of differential signal input terminals ADC_IN of the ΣΔADC acquisition circuit 3 .

[0047] The present invention will be described in more detail below through examples.

[0048] Example 1:

[0049] like Figure 1 As shown, this embodiment provides a platinum resistance high-precision acquisition circuit, including:

[0050] A pre-voltage divider circuit 1 includes a high-precision resistor and a platinum resistor, one end of the high-precision resistor is electrically connected to the power supply, the other end of the high-precision resistor is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground;

[0051] The driving enhancement circuit 2 is electrically connected to the pre-voltage divider circuit 1 and is used to enhance the driving capability of the pre-voltage divider circuit 1;

[0052] ΣΔADC acquisition circuit 3, the reference voltage input terminal REF is electrically connected to the voltage divider of the high-precision resistor via the drive enhancement circuit 2, the signal input terminal ADC_IN is electrically connected to the voltage divider of the platinum resistor via the drive enhancement circuit 2, and the signal output terminal serves as the output terminal of the acquisition circuit;

[0053] In this embodiment, the precision of the high-precision resistor is 0.05%;

[0054] The platinum resistance is from PT100Ω to PT1000 type;

[0055] The acquisition circuit is compatible with 2-wire, 3-wire and 4-wire sensor connections and has overvoltage protection function;

[0056] The full-scale accuracy of the acquisition circuit is 0.5°C, and it has open circuit, short circuit and over-range fault detection functions;

[0057] In this embodiment, the reference voltage input terminal REF is a pair of differential input terminals, and the input voltage of the pair of differential input terminals is the voltage across the high-precision resistor;

[0058] The signal input terminal ADC_IN is a pair of differential input terminals. The voltage collected by the differential input terminals is the voltage across the platinum resistor.

[0059] This embodiment provides a high-precision platinum resistance acquisition method, including:

[0060] One end of the high-precision resistor is electrically connected to the power supply, the other end is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground to form a pre-voltage divider circuit 1;

[0061] The voltage across the high-precision resistor is driven and enhanced to serve as a pair of differential reference voltages for the ΣΔADC acquisition circuit 3;

[0062] The voltage across the driven enhanced platinum resistor is collected using a pair of differential signal input terminals ADC_IN of the ΣΔADC acquisition circuit 3 .

[0063] The high-precision platinum resistance acquisition circuit proposed in the embodiments of the present invention is designed with a pre-voltage divider circuit, a drive enhancement circuit and a ΣΔADC acquisition circuit. Compared with the traditional constant current source acquisition circuit, the acquisition circuit has a compact structure, uses fewer components, and has low power consumption. It supports platinum resistances from 100Ω to 1kΩ, has a full-scale accuracy of 0.5°C, and is stable and reliable during the sampling process.

[0064] While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A platinum resistance high-precision acquisition circuit, characterized in that: include: A pre-voltage divider circuit includes a high-precision resistor and a platinum resistor, wherein one end of the high-precision resistor is electrically connected to a power supply, and the other end is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground; a driving enhancement circuit, electrically connected to the pre-voltage divider circuit, for enhancing the driving capability of the pre-voltage divider circuit; A ΣΔADC acquisition circuit, wherein the reference voltage input terminal is electrically connected to the voltage divider of the high-precision resistor via the drive enhancement circuit, the signal input terminal is electrically connected to the voltage divider of the platinum resistor via the drive enhancement circuit, and the signal output terminal serves as the output terminal of the acquisition circuit; The acquisition circuit has open circuit, short circuit and over-range fault detection functions; The reference voltage input terminal is a pair of differential input terminals, and the input voltage of the pair of differential input terminals is the voltage across the high-precision resistor; The signal input end is a pair of differential input ends, and the voltage collected by the pair of differential input ends is the voltage across the platinum resistor.

2. The acquisition circuit according to claim 1, characterized in that: The accuracy of the high-precision resistor is 0.05%; The platinum resistor is a platinum resistor of PT100Ω to PT1000 type.

3. The acquisition circuit according to claim 1, characterized in that: The acquisition circuit is compatible with 2-wire, 3-wire and 4-wire sensor connections.

4. The acquisition circuit according to claim 1, characterized in that: The acquisition circuit has an overvoltage protection function.

5. The acquisition circuit according to claim 1, characterized in that: The full-scale accuracy of the acquisition circuit is 0.5°C.

6. A high-precision platinum resistance acquisition method performed in the acquisition circuit according to any one of claims 1 to 5, characterized in that: include: One end of the high-precision resistor is electrically connected to the power supply, and the other end is electrically connected to one end of the platinum resistor, and the other end of the platinum resistor is electrically connected to the ground to form a pre-voltage divider circuit; The divided voltage of the high-precision resistor is driven and enhanced as a reference voltage of the ΣΔADC acquisition circuit; The signal input end of the ΣΔADC acquisition circuit is used to acquire the divided voltage of the driven enhanced platinum resistor.

7. The high-precision platinum resistance acquisition method according to claim 6, characterized in that: The method of using the divided voltage of the high-precision resistor as a reference voltage of the ΣΔADC acquisition circuit after driving enhancement includes: The voltage across the high-precision resistor is driven and enhanced to serve as a pair of differential reference voltages for the ΣΔADC acquisition circuit; Using the signal input end of the ΣΔADC acquisition circuit to collect the divided voltage of the driven enhanced platinum resistor includes: A pair of differential signal input terminals of the ΣΔADC acquisition circuit are used to acquire the voltage across the driven enhanced platinum resistor.

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