Temperature sensor acquisition circuit

Abstract

The utility model relates to the technical field of circuit control, and discloses a temperature sensor acquisition circuit, which comprises a constant voltage unit, a constant current unit, a differential operational amplifier unit and a voltage sampling unit, the constant voltage unit supplies power to the constant current unit, the constant current unit supplies power to a temperature sensor, the temperature sensor outputs voltage signals, and the differential operational amplifier unit supplies power to the voltage sampling unit. And after being amplified by the differential operational amplifier unit, the output voltage value of the temperature sensor is obtained by the voltage sampling unit, and the temperature measured by the temperature sensor is matched by the voltage value. According to the utility model, constant-current power supply is provided for the temperature sensor, and differential sampling is carried out on the output voltage to obtain accurate temperature data.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit control technical field especially relates to a temperature sensor acquisition circuit. BACKGROUND

[0002] The use of temperature sensor TP1000, generally through the direct power supply of direct current voltage, according to the resistance feedback of temperature sensor, obtain the real-time temperature value measured by temperature sensor. Due to the instability of power supply parameters, and the accuracy of measured resistance value and other problems, the resistance value error of measurement is larger, can only be applied to the occasion that the precision requirement is relatively low.

[0003] In laboratory detection, for the high temperature measurement precision requirement, fast response, ordinary temperature sensor circuit cannot meet this requirement. UTILITY MODEL CONTENTS

[0004] The utility model discloses a kind of temperature sensor acquisition circuits, provide constant current power supply for temperature sensor, and difference sampling is exported voltage, to obtain accurate temperature data.

[0005] The technical scheme adopted by the utility model is as follows:

[0006] A temperature sensor acquisition circuit, characterized by, including constant voltage unit, constant current unit, difference operational amplifier unit and voltage sampling unit, the constant voltage unit is powered for constant current unit, the constant current unit is powered for temperature sensor, the output voltage signal of the temperature sensor, after being amplified by the difference operational amplifier unit, the output voltage value of the temperature sensor is obtained by voltage sampling unit, the temperature measured by temperature sensor is matched by voltage value.

[0007] Further, the constant voltage unit includes DCDC conversion circuit and voltage operational amplifier circuit, the DCDC conversion circuit outputs 3V voltage, and the voltage operational amplifier circuit stabilizes 3V voltage to 0.5V.

[0008] Further, the output end of the DCDC conversion circuit is grounded through a capacitor.

[0009] Further, the input voltage of the DCDC conversion circuit is 3.3V, and is stabilized and output by voltage reference chip REF3030AIDBZR.

[0010] Further, the voltage operational amplifier circuit reduces 3V input voltage to 0.5V by voltage dividing resistance, and is stabilized and handled by operational amplifier circuit.

[0011] Further, the constant current unit provides 0.5mA current for temperature sensor by GS8331-TR linear circuit amplifier.

[0012] Furthermore, the differential operational amplifier unit amplifies the reference voltage after canceling it out by an AD8605ARTZ-REEL7 power amplifier, and then obtains the output voltage through a voltage sampling unit.

[0013] The beneficial effects of this utility model are:

[0014] (1) The constant voltage unit supplies power to the constant current unit, thereby improving the stability of the constant current source;

[0015] (2) A constant current source ensures the working stability of the temperature sensor;

[0016] (3) The differential operational amplifier unit cancels the reference voltage, improving the voltage measurement accuracy. Attached Figure Description

[0017] Appendix Figure 1 This is a DC-DC constant voltage circuit diagram;

[0018] Appendix Figure 2 This is a circuit diagram of a voltage operational amplifier;

[0019] Appendix Figure 3 This is a constant voltage filter circuit diagram;

[0020] Appendix Figure 4 This is a constant current circuit diagram;

[0021] Appendix Figure 5 This is a differential operational amplifier sampling circuit diagram. Detailed Implementation

[0022] The specific implementation of the temperature sensor acquisition circuit of this utility model will be described in detail below with reference to the accompanying drawings.

[0023] The temperature sensor acquisition circuit includes a constant voltage unit, a constant current unit, a differential operational amplifier unit, and a voltage sampling unit. The constant voltage unit powers the constant current unit, which in turn powers the temperature sensor. The output voltage signal of the temperature sensor is amplified by the differential operational amplifier unit, and the output voltage value of the temperature sensor is obtained by the voltage sampling unit. The temperature measured by the temperature sensor is then determined by matching the voltage value.

[0024] See appendix Figure 1 , 2 The constant voltage unit includes a DC-DC converter circuit and a voltage operational amplifier circuit. The input voltage of the DC-DC converter circuit is 3.3V, which is regulated by a voltage reference chip REF3030AIDBZR to output a constant voltage of 3.0V. By connecting a capacitor to ground at the output terminal, noise is further filtered out from the output voltage (see Appendix). Figure 3 ).

[0025] The output constant voltage of 3.0V is reduced to 0.5V through the voltage divider resistor of the voltage operational amplifier circuit.

[0026] Referring to the attached Figure 4 , the constant current unit outputs 0.5mA constant current for the temperature sensor by the GS8331-TR linear circuit amplifier and 0.5V voltage provided by the constant voltage source. The TEMPA end is connected to the power supply end of the temperature sensor.

[0027] Referring to the attached Figure 5 , the voltage signal of the temperature sensor is amplified by the differential amplifier unit, the differential amplifier unit amplifies after the reference voltage is offset by the AD8605ARTZ-REEL7 power amplifier, and then the output voltage is obtained by the voltage sampling unit. Figure 5 The parameters in the attached Figure 5 can amplify the voltage by 24.9 times. The TEMPA end in the figure is connected to the output end of the sensor.

[0028] Taking the temperature sensor PT1000 as an example, the voltage signal is converted into the resistance value of TP1000 by software, and the temperature value can be obtained by looking up the table according to the resistance value.

[0029] The above is only the preferred embodiment of the present application, it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, can also make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A temperature sensor acquisition circuit, characterized by: Including constant voltage unit, constant current unit, differential operational amplifier unit and voltage sampling unit, the constant voltage unit supplies power for the constant current unit, the constant current unit supplies power for the temperature sensor, the output voltage signal of the temperature sensor is amplified by the differential operational amplifier unit, and the output voltage value of the temperature sensor is obtained by the voltage sampling unit, the temperature measured by the temperature sensor is matched by the voltage value, the constant voltage unit includes DCDC conversion circuit and voltage operational amplifier circuit, the DCDC conversion circuit outputs 3V voltage, the voltage operational amplifier circuit stabilizes 3V voltage to 0.5V, the constant current unit outputs 0.5mA constant current for the temperature sensor by GS8331-TR linear circuit amplifier and 0.5V voltage provided by constant voltage source.

2. The temperature sensor harvesting circuit of claim 1, wherein: The output end of the DCDC conversion circuit is grounded through a capacitor.

3. The temperature sensor harvesting circuit of claim 1, wherein: The input voltage of the DCDC conversion circuit is 3.3V, which is stabilized by voltage reference chip REF3030AIDBZR for output.

4. The temperature sensor harvesting circuit of claim 1, wherein: The voltage operational amplifier circuit reduces 3V input voltage to 0.5V by dividing resistance, and stabilizes the voltage by operational amplifier circuit.

5. The temperature sensor harvesting circuit of any one of claims 1 to 3, wherein: The differential operational amplifier unit amplifies the reference voltage after offset, and then obtains the output voltage through the voltage sampling unit.

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