KR20060100627A - Adc measuring circuit unit capable of measuring stable adc input data in spite of fluctuating supply voltage - Google Patents

Abstract

Voltage supply means; Sensing means having a specific resistance that varies according to external factors; A voltage supply unit which receives a voltage of the voltage supply means through a supply voltage input terminal Vin and supplies a voltage to the sensing means connected in series with a resistor R1 and R2 to a supply voltage output terminal Vout; A reference voltage value with respect to the voltage supplied to the sensing means by receiving the voltage output from the supply voltage output terminal Vout from the node N1 of the resistors R1 and R2 through the reference voltage input terminal Vref. A reference voltage generation unit generating a; The ADC input value representing the voltage according to the change in the intrinsic resistance R3 of the sensing means measured by the voltage output from the supply voltage output terminal Vout is the node N2 of the resistor R2 and the intrinsic resistance R3. ADC input unit which is input through the ADC input terminal (ADCin) from the resistor (R4) connected to the; And an ADC calculating unit which calculates a ratio of the reference voltage value to the ADC input value to generate an ADC result value.

ADC, sensing means, sensor, battery, reference voltage

Description

ADC measuring circuit unit capable of measuring stable ADC input data in spite of fluctuating supply voltage

1 is a circuit diagram schematically showing an example of a conventional ADC measurement circuit device equipped with an illuminance sensor;

2 is a circuit diagram schematically showing an example of a conventional ADC measurement circuit device using a reference voltage;

3 is a circuit diagram showing an ADC measuring circuit device capable of measuring a stable ADC input value even with supply voltage fluctuations according to a preferred embodiment of the present invention; And

FIG. 4 is a block diagram schematically illustrating the configuration of a microcomputer in the ADC measurement circuit device of FIG. 3.

* Explanation of symbols for main parts of the drawings

100: battery 200: detection means

300: microcomputer 310: voltage supply unit

320: reference voltage generation unit 330: ADC input unit

340: ADC operation unit 350: ADC output unit

The present invention relates to an analog to digital conversion (ADC) measuring circuit device, and more particularly, it is possible to measure a stable ADC input from the sensing means even if the supply voltage supplied to the sensing means changes in resistance value according to an external factor. The present invention relates to an ADC measurement circuit device.

The ADC measuring circuit device is an ADC input value composed of voltages changing between an infinite number of values in theory, for example, an output from a sensing means for changing intrinsic resistance value when sensing light brightness, temperature, humidity, and sound. It is a device for outputting the analog voltage waveform and the like to the ADC output value which is a digital signal consisting of predefined dimensions or states. In addition, by transmitting the ADC output value corresponding to the ADC input value of the sensing means to a home network system connected by wireless or wired to the surrounding conditions (light brightness, temperature, humidity and sound, etc.) of the space in which the ADC measurement circuit device is installed. Make the home network system aware.

Hereinafter, a conventional ADC measurement circuit device will be described with reference to the drawings.

1 is a circuit diagram schematically showing an example of a conventional ADC measurement circuit device equipped with an illuminance sensor, Figure 2 is a circuit diagram schematically showing an example of an ADC measurement circuit device using a conventional reference voltage.

Conventional ADC measuring circuit device, as shown in Figure 1, the illumination sensor 20 for measuring the brightness of the light by receiving the operating voltage from the battery 10, which is a low power supply means, a plurality of resistors (R1, R2) The microcomputer 30 receives the ADC input values of the circuit stability capacitor C and the illuminance sensor 20 through the ADC input terminal ADC, and converts the ADC input values into ADC output values to measure the brightness of light.

However, in the ADC measuring circuit device using the battery 10 as a low power supply means as described above, the supply voltage supplied to the illumination sensor 20 changes as the voltage of the battery 10 is depleted, so that the illumination sensor 20 Even if the same amount of light is detected, there is a problem that the ADC input value input to the microcomputer 30 has an error.

ADC measurement circuit device using a reference voltage for solving the above problems, as shown in Figure 2, the Vref terminal of the microcomputer 30 from the battery 10, which is a low power supply means to the conventional ADC measurement circuit ( Vref) and a constant voltage circuit 40 and a resistor R3 using a constant voltage IC or a constant voltage diode for supplying a stable voltage to the illuminance sensor 20 are further configured, and are supplied from the battery 10 to the illuminance sensor 20. When the operating voltage changes, the ADC input value of the illuminance sensor 20 corresponding to the change amount of the supply voltage supplied to the illuminance sensor 20 is measured based on the reference voltage supplied to the Vref terminal Vref.

However, as described above, the ADC measuring circuit device that receives the reference voltage from the constant voltage circuit 40 has a higher cost as a separate constant voltage circuit 40 is configured, and the current of the battery 10 is constant voltage circuit 40. Is consumed and shortens the life of the battery 10.

Accordingly, an object of the present invention is to provide an ADC measuring circuit device capable of measuring a stable ADC input value even with a change in supply voltage without configuring a separate constant voltage circuit.

In addition, another object of the present invention is to provide an ADC measuring circuit device that can extend the life of the battery by minimizing the current consumption of the battery which is a low power supply means.

According to the invention, the voltage supply means; Sensing means having a specific resistance that varies according to external factors; A voltage supply unit which receives a voltage of the voltage supply means through a supply voltage input terminal Vin and supplies a voltage to the sensing means connected in series with a resistor R1 and R2 to a supply voltage output terminal Vout; A reference voltage value with respect to the voltage supplied to the sensing means by receiving the voltage output from the supply voltage output terminal Vout from the node N1 of the resistors R1 and R2 through the reference voltage input terminal Vref. A reference voltage generation unit generating a; The ADC input value representing the voltage according to the change in the intrinsic resistance R3 of the sensing means measured by the voltage output from the supply voltage output terminal Vout is the node N2 of the resistor R2 and the intrinsic resistance R3. ADC input unit which is input through the ADC input terminal (ADCin) from the resistor (R4) connected to the; And an ADC calculating unit which calculates a ratio of the reference voltage value to the ADC input value to generate an ADC result value.

In this case, the reference voltage value preferably has a value according to the formula Vref = {(R2 + R3) / (R1 + R2 + R3)} * Vcc.

At this time, the ADC input value preferably has a value of the formula: ADC = {R3 / (R1 + R2 + R3)} * Vcc.

At this time, the ADC output value preferably has a value according to the formula X = ADC / Vref by an algorithm for reducing the measurement error of the sensing means in accordance with the voltage change of the power supply means.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

FIG. 3 is a circuit diagram illustrating an ADC measuring circuit device capable of measuring a stable ADC input value even when supply voltage fluctuations according to a preferred embodiment of the present invention, and FIG. 4 schematically illustrates the configuration of a microcomputer in the ADC measuring circuit device of FIG. 3. It is a block block diagram shown.

As shown in FIG. 3, the ADC measuring circuit device according to the preferred embodiment of the present invention includes a battery 100, a sensing means 200, and a battery in which a value of the specific resistance R 3 varies according to external factors. The reference voltage corresponding to the supply voltage of 100 is generated and the supply voltage is supplied to the sensing means 200 to calculate the measured value of the sensing means 200 based on the reference voltage to change the supply voltage of the battery 100. It includes a microcomputer 300 for reducing the error of the measured value.

The battery 100 is generally preferably a low power supply means such as a battery for supplying a voltage of DC 3V.

The sensing means 200 is a sensor that generates an ADC input value, such as various sensors, such as an illuminance sensor, a temperature sensor, a humidity sensor, an infrared sensor, and the like, in which a specific resistance value is changed when sensing light brightness, temperature, humidity, and sound. Means.

As shown in FIGS. 3 and 4, the microcomputer 300 receives operating power from the battery 100 through the supply voltage input terminal Vin, and provides resistors R1 and R2 to the supply voltage output terminal Vout. Input the voltage output from the voltage supply unit 310 for supplying a voltage to the sensing means 200 and the supply voltage output terminal Vout from the node N1 of the resistors R1 and R2. The sensing means measured by the voltage output from the supply voltage output terminal (Vout), the reference voltage generator 320 for generating a reference voltage value for the voltage supplied to the sensing means 200 received through the terminal (Vref) The ADC input value according to the change in the specific resistance R3 of the 200 is input from the resistor R4 connected to the node N2 of the resistor R2 and the specific resistance R3 through the ADC input terminal ADC. The ADC input value so that the measurement error of the sensing means 200 according to the voltage change of the ADC input unit 330 and the battery 100 is reduced ADC operation unit 340 for generating the ADC output value by calculating the ratio of the reference voltage value for the ADC output unit 350 for outputting the ADC output value to the external home network system by wire or wirelessly through the ADC output terminal (ADCout) It includes. The reference voltage generator 320 and the ADC input unit 330 may further include circuit stabilizing capacitors C1 and C2 for protecting the circuits, respectively.

In addition, the microcomputer 300 may include an algorithm for calculating a ratio of the reference voltage value and the ADC input value such that the measurement error of the sensing means 200 according to the voltage variation of the battery 100 is reduced, and the battery 100. In order to minimize current consumption, it is preferable to include an algorithm for supplying the voltage of the battery 100 to the sensing means 200 only when a control signal of the sensing means 200 is received from an external home network system.

Here, the reference voltage value generated by the reference voltage input unit 320 is represented by Vref = {(R2 + R3) / (R1 + R2 + R3)} * Vcc according to the circuit design as shown in FIG. Has a value of

In addition, the ADC input value input to the ADC input unit 330, as shown in Figure 3, has a value according to the formula: ADC = {R3 / (R1 + R2 + R3)} * Vcc according to the circuit design.

In addition, the ADC output value generated by the ADC operator 340 has a value according to the equation X = ADC / Vref by an algorithm for reducing the measurement error of the sensing means 200 according to the voltage variation of the battery 100. .

Hereinafter, the theoretical ADC output value calculated by the above equation and the experimental ADC result value measured by the algorithm with respect to the ADC input value of the sensing means measured by the ADC measuring circuit device according to the preferred embodiment of the present invention. It is as follows.

Here, the values of the resistors R1, R2, and R3 are respectively R1 = 200 ??, R2 = 5.1 k ?? And R3 = 1.7 k ?? and the supply voltages supplied from the battery 100 were Vcc = 3.0 V and Vcc = 2.2 V, respectively.

First, the ADC output value according to the calculation formula of the ADC measuring circuit device of the present invention is as follows.

When the voltage output from the supply voltage output terminal Vout when the supply voltage of the battery 100 input to the supply voltage input terminal Vin of the microcomputer 300 is Vcc = 3.0 V, Vcc-a,

The reference voltage value is Vref-a = {(R2 + R3) / (R1 + R2 + R3)} * Vcc-a = 2.914 V,

The ADC input value is ADC-a = {R3 / (R1 + R2 + R3)} * Vcc-a = 0.729 V,

The ADC output value is X-a = ADC-a / Vref-a = 0.2501.

Further, when the supply voltage of the battery 100 input to the supply voltage input terminal Vin of the microcomputer 300 is Vcc = 2.2 V, the voltage output from the supply voltage output terminal Vout is Vcc-b.

The reference voltage value is Vref-b = {(R2 + R3) / (R1 + R2 + R3)} * Vcc-b = 2.137 V,

The ADC input value is ADC-b = {R3 / (R1 + R2 + R3)} * Vcc-b = 0.534 V,

The ADC output value is X-b = ADC-b / Vref-b = 0.2498.

Therefore, even if the value of the supply voltage Vcc of the battery 100 is changed from 3.0 V to 2.2 V (about 30% change) and supplied to the sensing means 200, the ADC corresponding to the ADC input value measured by the sensing means 200. The output value (deviation between Xa and Xb) has an error within 1%.

On the other hand, the ADC output value by the algorithm of the ADC measuring circuit device of the present invention is as follows.

Vcc ADC input value ADC output value 3.0 V 0.804 V 291 2.2 V 0.578 V 285

Therefore, even if the value of the supply voltage Vcc of the battery 100 is changed from 3.0 V to 2.2 V (approximately 30% change) and supplied to the sensing means 200, the ADC output value indicating the ratio of the reference voltage value to the ADC input value is As the difference of less than 5% is shown, a reliable ADC output value can be obtained.

Therefore, the ADC measuring circuit apparatus according to the present invention calculates the ratio of the ADC input value of the sensing means to the reference voltage value with respect to the supply voltage even if the supply voltage of the battery supplied to the sensing means changes to provide a reliable ADC output value. You can print

In addition, by supplying the battery supply voltage only when the ADC input value of the sensing means is required without applying the conventional constant voltage means, more economical circuit design is possible and the unnecessary current consumption is minimized to prolong the battery life. You can do that.

In the above-described invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the invention. Thus, the scope of the invention should not be defined by the described embodiments, but should be defined by the equivalents of the claims and claims.

As described above, according to the ADC measuring circuit device according to the present invention, it is possible to design a circuit more economically by not configuring a separate constant voltage circuit, thereby minimizing the current consumption of the battery can extend the life of the battery.

In addition, by calculating the ratio of the ADC input value of the sensing means to the reference voltage value of the voltage supplied from the battery to the sensing means to output the corresponding ADC output value, even if the supply voltage of the battery fluctuates reliable ADC output value Can be generated.

Claims (4)

Voltage supply means; Sensing means having a specific resistance that varies according to external factors; A voltage supply unit which receives a voltage of the voltage supply means through a supply voltage input terminal Vin and supplies a voltage to the sensing means connected in series with a resistor R1 and R2 to a supply voltage output terminal Vout; A reference voltage value with respect to the voltage supplied to the sensing means by receiving the voltage output from the supply voltage output terminal Vout from the node N1 of the resistors R1 and R2 through the reference voltage input terminal Vref. A reference voltage generation unit generating a; The ADC input value representing the voltage according to the change in the intrinsic resistance R3 of the sensing means measured by the voltage output from the supply voltage output terminal Vout is the node N2 of the resistor R2 and the intrinsic resistance R3. ADC input unit which is input through the ADC input terminal (ADCin) from the resistor (R4) connected to the; And ADC measuring circuit device capable of measuring the stable ADC input value even if the supply voltage fluctuations, characterized in that it comprises an ADC calculation unit for generating the ADC result by calculating the ratio of the reference voltage value to the ADC input value. The method of claim 1, wherein the reference voltage value is a Vref = {(R2 + R3) / (R1 + R2 + R3)} * Vcc measurement stable ADC input value, characterized in that the supply voltage fluctuations, characterized in that ADC measurement circuitry available. 3. The ADC measurement according to claim 2, wherein the ADC input value has a value based on an equation of ADC = {R3 / (R1 + R2 + R3)} * Vcc. Circuitry. 4. The supply voltage fluctuation of claim 3, wherein the ADC output value has a value according to the formula X = ADC / Vref by an algorithm for reducing the measurement error of the sensing means caused by the voltage fluctuation of the power supply means. ADC measuring circuit device that can measure stable ADC input value.

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