KR102128024B1 - Apparatus and method for sensing registance with ripple reduction - Google Patents

Abstract

The resistance sensing device according to an embodiment of the present invention generates a feedback current for removing a ripple included in a signal for the resistance value, and a sensor unit for obtaining a physical signal and converting it into a resistance value. By doing so, it may include a voltage converter for converting the resistance value into a voltage from which the ripple is removed, and a filtering unit for dividing the voltage from which the ripple is removed into AC voltage and DC voltage, and filtering the AC voltage. have.

Description

Resistive device and method for reducing ripple {APPARATUS AND METHOD FOR SENSING REGISTANCE WITH RIPPLE REDUCTION}

The present invention relates to a resistance sensing device and method for sensing resistance to physical properties using ripple reduction technology.

In general, a circuit can sense the electrical characteristics of voltage, current, resistance, and capacitor, but not physical properties such as pressure and temperature. In order for the circuit to sense the physical properties, a device that serves to convert the physical properties into electrical properties, that is, a sensor is required.

With the development of electronic technology, research and development for sensors that convert physical properties into electrical properties are actively being conducted. Generally, a sensor senses a physical property and converts it into a single resistor so that the physical property is sensed through the connected circuit.

On the other hand, in general, a physical property may appear as a value that changes in real time rather than a fixed one. For example, there may be a physical property having a form of a signal that changes in real time, such as a pulse wave. In the case of these physical properties, it is difficult to measure accurately because it changes in real time. Accordingly, a method for minimizing errors and more accurate detection of physical properties is required.

Korean Registered Patent No. 10-1125236 (registered on March 02, 2012)

The problem to be solved by the present invention is to convert the resistance value obtained for a physical property into a voltage and to correct the physical property more accurately by correcting the voltage for the resistance value using a feedback current provided through a ripple reduction circuit to the converted voltage. It is to provide a resistance sensing device for sensing.

However, the problems to be solved by the present invention are not limited to those mentioned above, but are not mentioned, but include the purpose that can be clearly understood by those skilled in the art from the following description can do.

The resistance sensing device according to an embodiment of the present invention generates a feedback current for removing a ripple included in a signal for the resistance value, and a sensor unit for obtaining a physical signal and converting it into a resistance value. By doing so, it may include a voltage converter for converting the resistance value into a voltage from which the ripple is removed, and a filtering unit for dividing the voltage from which the ripple is removed into AC voltage and DC voltage, and filtering the AC voltage. have.

In addition, the resistance value may include a constant value or a variable value based on the characteristics of the physical signal.

In addition, the voltage conversion unit further includes a chopper unit, a ripple reduction unit, and an amplification unit, and the output terminal of the chopper unit is connected to the output terminal of the ripple reduction unit and the input terminal of the amplification unit, and the input terminal of the ripple reduction unit is connected to the output terminal of the amplification unit. Can.

In addition, the ripple reduction unit obtains information about the size of the ripple using the voltage output through the amplification unit, and generates the feedback current corresponding to the size of the ripple based on the obtained information, but removing the ripple. The voltage converter may provide the feedback current by using the ripple reduction unit.

In addition, an analog to digital converter (ADC) unit for converting the physical signal into a digital signal, wherein the ADC converts the DC voltage and the AC voltage on which the filtering is not performed to a digital signal. Can.

Also, the filtering unit may include a band pass filter (BPF).

The resistance detecting apparatus according to an embodiment of the present invention includes the steps of obtaining a physical signal and converting it into a resistance value, generating a feedback current removing ripple included in the signal for the resistance value, and the resistance value And converting the ripple-removed voltage into an AC voltage, and dividing the ripple-removed voltage into an AC voltage and a DC voltage, and filtering the AC voltage.

In addition, the resistance value may include a constant value or a variable value based on the characteristics of the physical signal.

In addition, the generating of the feedback current may include obtaining information about the size of the ripple using the converted voltage, and corresponding to the size of the ripple based on the obtained information, but removing the ripple. And generating a feedback current.

In addition, the step of converting the physical signal to a digital signal, and the step of converting the digital signal, the step of converting the DC voltage and the AC voltage is the filtering is not performed is converted to a digital signal It may include.

Also, the step of performing the filtering may include performing the filtering using a band pass filter (BPF).

The resistance sensing apparatus and method according to an embodiment of the present invention may allow the physical characteristics to be detected more accurately by correcting the voltage based on the resistance value of the physical characteristics using a ripple reduction unit.

However, the effects that can be obtained in the present invention are not limited to the above-mentioned effects, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description. Will be able to.

1 is a conceptual diagram of a resistance sensing device according to an embodiment of the present invention.
2 shows an example of a functional configuration of a resistance sensing device according to an embodiment of the present invention.
Figure 3 shows an example of the flow of each step of the resistance detection method according to an embodiment of the present invention.
4 shows an example of a circuit of a resistance sensing device and an example of current and voltage output by the resistance sensing device according to an embodiment of the present invention.
Figure 5 shows an example of the result for the current of the resistance is reduced ripple by the resistance sensing device and method according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments allow the disclosure of the present invention to be complete, and those skilled in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the scope of the invention is only defined by the claims.

In describing the embodiments of the present invention, detailed descriptions of known functions or configurations will be omitted except when actually necessary in describing the embodiments of the present invention. In addition, terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition should be made based on the contents throughout this specification.

The present invention can be applied to various changes and may include various embodiments, and specific embodiments will be illustrated in the drawings and described in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood as including all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as first and second may be used to describe various components, but the corresponding components are not limited by these terms. These terms are only used to distinguish one component from another.

When a component is said to be'connected' or'connected' to another component, it is understood that other components may be directly connected to or connected to the other component, but other components may exist in the middle. It should be.

1 is a conceptual diagram of a resistance sensing device according to an embodiment of the present invention.

Referring to FIG. 1, the resistance sensing device 100 includes a sensor unit 110, a voltage converter 120, a filtering unit 130, an analog-digital converter (ADC) 140, and an interface 150 Can.

The sensor unit 110 may sense physical characteristics such as pressure, temperature, pulse wave, and the like, and convert it into a resistance value. The sensor unit 110 may be connected to the voltage converter 120. One end of the sensor unit 110 may be connected to a power source V _DD , and the other end of the sensor unit 110 may be connected to another component (chopper unit 121) of the voltage converter 120.

The voltage converter 120 may convert the resistance value of the single mode of the sensor unit 110 into the voltage of the differential mode. The voltage converter 120 converts a constant resistance value, for example, a constant voltage (DC voltage) in the case of a specific resistance element, and changes a resistance value, for example, a resistance value for a physical property that changes in real time. Can be converted to a voltage (AC voltage).

Specifically, the voltage converter 120 may include a chopper part 121, an amplification part 123, and a ripple reduction part 125.

The input terminal of the chopper unit 121 may be connected to the sensor unit 110, and the output terminal may be connected to the input terminal of the amplification unit 123 and the output terminal of the ripple reduction unit 125. Based on this connection, the chopper unit 121 may convert a current reflecting a resistance value generated by applying a single mode voltage to a differential mode and provide it to the amplifying unit 123.

The amplification unit 123 may receive the current converted into the differential mode by the chopper unit 121 and convert it into a voltage signal. The input terminal of the amplifying unit 123 may be connected to the output terminal of the chopper unit 121 and the output terminal of the ripple reduction unit 125.

The ripple reduction unit 125 may reduce the ripple included in the signal by providing a feedback current for the signal output by the amplification unit 123. The input terminal of the ripple reduction unit 125 may be connected to the output terminal of the amplifying unit 123, and the output terminal may be connected to the output terminal of the chopper unit 121 and the input terminal of the amplifying unit 123. Based on this connection, the ripple reduction unit 125 may provide the feedback current periodically or continuously.

The voltage converted by the voltage converter 120 is divided into AC and DC, and may be provided in different configurations. Specifically, among the voltages converted by the voltage converter 120, AC is provided to the filtering unit 130, filtered by the filtering unit 130, and then provided to the ADC 140, and DC is directly the ADC 140 It can be provided as.

The ADC 140 may convert the received signal into a digital signal and provide it to the interface 150. The interface 150 may provide the converted digital signal to other devices. The interface 150 may include, for example, a Serial Peripheral Interface (SPI), but is not limited thereto, and may be implemented with various interfaces that function as a bus.

The digital signal converted through the interface 150 may be provided to a microcontroller unit (MCU). The MCU may be a semiconductor included in most electronic products and serves to control functions, and in this regard, it will be omitted as it is easy for a person skilled in the art.

In the above, an example of the configuration of the resistance sensing device 100 is conceptually described, and an example of a more specific circuit of the resistance sensing device 100 will be described later in FIG. 4.

2 shows an example of a functional configuration of a shielding device according to an embodiment of the present invention. Used below… The term'sub' means a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

Referring to FIG. 2, the resistance sensing device 100 may include a sensor unit 110, a voltage converter 120, a filtering unit 130, and an ADC 140. Here, the voltage conversion unit 120 may be composed of a chopper unit 121, an amplification unit 123, and a ripple reduction unit 125.

The sensor unit 110 may acquire a physical signal and convert it into a resistance value. The physical signal is a signal representing physical characteristics such as pressure, temperature, pulse wave, etc., and the signal may have a constant value or a variable value. The sensor unit 110 may be disposed to obtain a physical signal by being exposed to the outside of the resistance sensing device 100.

The voltage converter 120 converts the input voltage by the power source V _DD into a current reflecting the resistance value according to the resistance value of the sensor unit 110 so that a current according to the resistance value is formed. Specifically, the voltage converter 120 applies a voltage (input voltage) to the resistance value of the sensor unit 110 based on the power source V _DD being connected to one end of the sensor unit 110 to obtain a resistance value. It can be converted into reflected current. At this time, the converted current may be a single mode, and the voltage converter 120 corrects the converted voltage by using a feedback current that reduces the ripple and converts to a differential mode for the current reflecting the resistance value and filters (130). That is, the voltage converter 120 may convert the resistance value by the sensor unit 110 to a voltage from which ripple is removed.

We will look at each configuration of the voltage converter 120.

The chopper part 121 may be connected to the other end of the sensor part 110, that is, the other end that is not connected to the power source V _DD . Based on this, the chopper unit 121 may receive a signal in a single mode for the current value generated in response to the voltage being provided to the sensor unit 110. The chopper unit 121 may improve the resolution of resistance sensing by converting a signal input in a single mode into a differential mode. The signal output by the chopper part 121 may be applied to the amplification part 123.

The amplification unit 123 may convert a current signal converted into a differential mode by the chopper unit 121 into a voltage signal. The amplification unit 123 may provide the converted voltage signal to the ripple reduction unit 125 and the filtering unit 130, respectively.

The ripple reduction unit 125 may determine whether ripple is included in the signal based on receiving the signal from the amplification unit 123. The ripple reduction unit 125 may measure the magnitude of ripple present in the signal as the signal is provided, and generate a feedback current corresponding to the ripple size but canceling the ripple.

The ripple reduction unit 125 generates a feedback current and provides it to an input terminal (or an output terminal of the chopper unit 121) of the amplifying unit 123, thereby removing ripples included in the signal applied to the amplifying unit 123 (offset). can do. The ripple reduction unit 125 may update the feedback current by continuously measuring the ripple of the signal output by the amplification unit 123. To this end, the ripple reduction unit 125 and the amplification unit 123 may be connected to each other in a form in which the input terminal and the output terminal are connected, that is, in the form of a loop.

Meanwhile, the ripple canceled signal may be a voltage signal, and the filtering unit 130 may divide the ripple canceled signal into AC voltage and DC voltage, and perform filtering on the AC voltage. The filtering unit 130 may be connected to the voltage converter 120 in series to remove the DC voltage and allow the magnitude of the AC voltage to be amplified. The filtering unit 130 may filter a portion other than the frequency band of the signal related to the resistance value (eg, the frequency band of the power supply 60Hz), that is, a frequency band mostly related to noise. The filtering unit 130 may include, for example, a band pass filter (BPF).

The ADC 140 is a converter that converts an analog signal to a digital signal, and converts a DC voltage that has not been filtered into a digital signal, and converts the AC voltage that has been filtered into a digital signal. The ADC 140 is easy for a person skilled in the art, and a detailed description will be omitted.

Figure 3 shows an example of the flow of each step of the resistance detection method according to an embodiment of the present invention.

Referring to FIG. 3, a physical signal may be converted into a resistance value by the sensor unit 110 (S110 ). For example, when a physical signal (or physical resistance), such as pressure or temperature, is applied to the sensor unit 110, the resistance of the sensor unit 110 changes, but the change in resistance is measured by the sensor unit 110. Based on this, the physical signal is converted into a resistance value. In this case, the resistance value may be represented by the sum of R represented by a constant value and R represented by a variable value.

The resistance value may be provided to the voltage converter 120 in the form of a current signal as voltage is applied. A feedback current that cancels (or removes) the ripple of the signal with respect to the resistance value may be generated by the ripple reduction unit 125 of the voltage converter 120 (S120). Specifically, the ripple reduction unit 125 may identify a signal output through the amplification unit 123 and measure the ripple included therein. Accordingly, the ripple reduction unit 125 may generate a feedback current that cancels the ripple.

At this time, a ripple may be included in the signal for the resistance value. By providing a feedback current to the signal for the resistance value, the ripple of the signal for the resistance value may be canceled (S130). The feedback current may be applied between the chopper part 121 and the amplifying part 123, and may be applied to the amplifying part 123 after ripple is canceled out by the signal output by the chopper part 121.

Accordingly, the amplifying unit 123 may generate a signal whose ripple is canceled. The ripple canceled signal is divided into an AC voltage and a DC voltage by the filtering unit 130, and filtering may be performed on the AC voltage (S140).

In some cases, the ripple canceled signal may be a voltage signal, and may appear in the form of a sum of AC voltage and DC voltage. Here, the AC voltage may be a voltage for a variable resistor, and the DC voltage may be a voltage for a resistor having a constant value. The reason why the voltage appears in the form of the sum of the AC voltage and the DC voltage is that the resistance value is represented by a constant value of R and a variable value of R due to the characteristics of the physical signal sensed by the sensor unit 110. Can.

4 shows an example of a circuit of a resistance sensing device and an example of current and voltage output by the resistance sensing device according to an embodiment of the present invention. The circuit 200 of FIG. 4 may be at least a part of a circuit constituting the resistance sensing device 100, and the resistance sensing device 100 of the present invention is not limited thereby.

The circuit 200 of FIG. 4 includes a sensor unit 110, a chopper unit 121, an amplification unit 123, and a ripple reduction unit 125.

The sensor unit 110 senses a physical signal based on the voltage applied by the power source V _DD to convert it into a resistance value. The sensor unit 110 may sense a physical signal through a change in R _SENSE , which is a resistance element to measure a resistance value. For example, the sensor unit 110 may detect a change in resistance by the pressure of the pulse wave in relation to a physical signal called pulse wave, and indicate the pulse wave as a resistance value. Meanwhile, since a physical signal such as a pulse wave changes in real time, it may appear in the form of'R+R'.

One end of the sensor unit 110 is connected to the power supply V _DD , and the other end of the sensor unit 110 may be connected to one end of the first switch 121-1 and the third switch 121-3 of the chopper unit 121, respectively. have. The chopper part 121 receives a voltage in a single mode based on the connection with the sensor part 110. The chopper unit 121 converts the input voltage to a first differential voltage (V _OP ) and a second differential voltage (V _ON ) in the form of square waves that are symmetrical to each other around the reference voltage, and outputs the converted voltage.

The chopper part 121 may include a first switch 121-1, a second switch 121-2, a third switch 121-3, and a fourth swatch 121-4, respectively. The voltage can be converted from a single mode to a differential mode using an on/off switch and output. At this time, some switches have on/off control at the same time point, that is, at the same clock.

For example, the second switch 121-2 and the third switch 121-3 are turned on/off in the same clock, and the first switch 121-1 and the fourth switch 121-4 are On/off is done in the same clock. In this regard, referring to reference number 1a, the first switch 121-1 and the fourth switch 121-4 are turned on at the first time point 310, and the second switch (at the second time point 320 ). 121-2) and the third switch 121-3 may be turned on.

The amplifying unit 123 may include a plurality of operational amplifiers having two input terminals and one output terminal as illustrated, and the signal converted into the differential mode by the chopper unit 121 may be an amplifying unit. It can be amplified through the operational amplifier of (123). For example, the first differential voltage V _ON by the chopper unit 121 is applied to the first operational amplifier 123-1, and the second differential voltage V _OP is the second operational amplifier 123-2. ), each of which can be amplified and output.

Also, the amplifying unit 123 may include a plurality of switches. For example, as shown, the fifth switch 123-3, the sixth switch 123-4, the seventh switch 123-5, the eighth on the output end side of the operational amplifier of the amplifier 123 The switch 123-6 can be arranged. At this time, the fifth switch 123-3 and the eighth switch 123-6 are turned on/off at the first time point 310, and the sixth switch 123-4 and the seventh switch 123- 5) may be turned on/off at the second time point 320.

The voltage amplified and output by the amplifying unit 123 may be provided to the ripple reducing unit 125. On the other hand, the offset voltage (V _OS ) of the operational amplifier, which acts as a cause of decreasing accuracy, may be present in the amplifying unit 123. Accordingly, inevitably, ripple is present in the voltage that is first amplified by the amplifying unit 123, that is, the voltage before the feedback current to be described later is provided. For example, ripple ERROR may occur in the output voltages V _OUTP and V _OUTN as shown in reference number 1b.

The ripple reduction unit 125 may include a capacitor 125-1, a chopper circuit 125-2, a first operator 125-3, and a second operator 125-4. Capacitor 125-1 is connected to each of the two input terminal side, it is possible to measure the size of the ripple included in the voltage applied to the ripple reduction unit 125. The chopper circuit 125-2 may periodically adjust the direction of ripple input to the first operator 125-3 by periodically changing the path of the voltage output through the capacitor. Accordingly, the chopper circuit 125-2 can help the first operator 125-3 to accumulate information about ripple.

The voltage output through the chopper circuit 125-2 may be applied to the first operator 125-3. The first operator 125-3 may accumulate information about ripple to determine the magnitude of the feedback current. For example, when the voltage applied to the ripple reduction unit 125 includes 1V of ripple, the first operator 125-3 stores information about the size of the ripple, and the second operator 125 described below -4) can adjust the amount of feedback current to reduce ripple. Thereafter, when the voltage applied to the ripple reduction unit 125 includes a ripple of 1 V or less, the above-described process may be repeated until the ripple is removed. If there is no ripple of the voltage applied thereafter, the magnitude of the feedback current can be maintained.

The second operator 125-4 may adjust the size of the feedback current based on information about the size of the ripple by the first operator 125-3. The second operator 125-4 may be, for example, a current amplifier (transconductor). The feedback current adjusted by the second operator 125-4 is provided to the input terminal of the amplifying unit 123, as shown, to the voltage to be amplified by the amplifying unit 123, that is, to the chopper unit 121. It is possible to cancel the ripple for the first differential voltage (V _OP ) and the second differential voltage (V _ON ) provided by. Accordingly, ripple may be canceled out in the final voltage output from the amplifying unit 123.

Figure 5 shows an example of the result for the current of the resistance is reduced ripple by the resistance sensing device and method according to an embodiment of the present invention.

Referring to FIG. 5, the graph 300 shows an example of a voltage converted by the voltage converter 120 and a voltage filtered by the filtering unit 130 for a physical signal. As shown in the figure, the physical signal may appear in a changing form in real time. Accordingly, the converted voltage also appears in a form of changing in real time.

Reference numeral 2a shows an enlarged part of the graph 300. According to reference number 2a, the voltage obtained by the resistance sensing device 100 and the method according to an embodiment of the present invention is physically eliminated by the ripple generated by the offset voltage (V _OS ) of the operational amplifier acting as an error You can see that it is output in the same form as the signal.

When looking at the voltage filtered by the filtering unit 130, it can be seen that unnecessary signals are removed from the voltage before filtering, so that the characteristics of the physical signal are better displayed.

Since this filtering is performed before being input to the ADC, that is, filtering is performed at the analog stage, some components of the digital system may be omitted, thereby miniaturizing the system, and also signal to noise (SNR) for the input signal. ratio).

Resistance detection apparatus 100 and method according to an embodiment of the present invention, by improving the resolution of the resistance detection by converting to a differential mode for the resistance value of the physical signal input in a single mode, the voltage (or The signal representing the voltage) can make the characteristics of the physical signal more visible, so that accurate resistance detection can be achieved.

Resistance detection apparatus 100 and method according to an embodiment of the present invention, by making the ripple included in the voltage cancel out through the ripple reduction unit 125 to minimize the error included in the voltage to ensure accurate resistance detection Can.

The resistance detecting apparatus 100 and the method according to an embodiment of the present invention are performed by the filtering unit 130 before filtering of the voltage converted by the voltage converter 120 is input to the ADC, that is, filtering at an analog stage Since this is performed, some components of the digital system may be omitted, so that the system may be miniaturized, and signal to noise ratio (SNR) for an input signal may be increased.

Combinations of each block in the block diagrams and respective steps in the flowcharts attached to this specification may be performed by computer program instructions. These computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, so that instructions performed through a computer or other programmable data processing equipment processor may be used in each block or flowchart of the block diagram. In each step, means are created to perform the functions described. These computer program instructions can also be stored in computer readable or computer readable memory that can be oriented to a computer or other programmable data processing equipment to implement a function in a particular way, so that computer readable or computer readable memory The instructions stored in it are also possible to produce an article of manufacture containing instructions means for performing the functions described in each step of each block or flowchart of the block diagram. Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so a series of operational steps are performed on a computer or other programmable data processing equipment to create a process that is executed by the computer to create a computer or other programmable data. It is also possible for instructions to perform processing equipment to provide steps for performing the functions described in each block of the block diagram and in each step of the flowchart.

Further, each block or each step can represent a module, segment, or portion of code that includes one or more executable instructions for executing the specified logical function(s). It should also be noted that in some alternative embodiments it is also possible that the functions mentioned in blocks or steps occur out of order. For example, two blocks or steps shown in succession may in fact be executed substantially simultaneously, or it is also possible that the blocks or steps are sometimes performed in reverse order depending on the corresponding function.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential quality of the present invention. Therefore, the embodiments disclosed in the present specification are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

100: resistance sensing device
110: sensor unit
120: voltage converter
121: chopper part
123: amplification section
125: ripple reduction unit
130: filtering unit
140: ADC

Claims (9)

A sensor unit that acquires a physical signal and converts it into a resistance value,
A voltage converter connected to the sensor unit to generate a feedback current for removing ripple included in the signal for the resistance value, and converting the resistance value into a voltage from which the ripple is removed;
And a filtering unit for dividing the voltage from which the ripple is removed into AC voltage and DC voltage, and filtering the AC voltage.
Resistance sensing device. According to claim 1,
The voltage converter further includes a chopper part, a ripple reduction part, and an amplification part,
The output terminal of the chopper unit is connected to the output terminal of the ripple reduction unit and the input terminal of the amplification unit,
The input terminal of the ripple reduction unit is connected to the output terminal of the amplification unit
Resistance sensing device. According to claim 2,
The ripple reduction unit
Acquiring information about the size of the ripple using the voltage output through the amplifying unit, and generating the feedback current corresponding to the size of the ripple but removing the ripple based on the obtained information,
The voltage converter provides the feedback current using the ripple reduction unit
Resistance sensing device. According to claim 1,
And an analog to digital converter (ADC) that converts the voltage from which the ripple is removed into a digital signal.
The ADC converts the DC voltage that has not been filtered and the AC voltage that has been filtered into a digital signal.
Resistance sensing device. According to claim 1,
The filtering unit includes a band pass filter (BPF)
Resistance sensing device. Obtaining a physical signal and converting it into a resistance value,
Generating a feedback current to remove the ripple included in the signal for the resistance value,
Converting the resistance value into a voltage from which the ripple is removed,
And dividing the voltage from which the ripple is removed into AC voltage and DC voltage, and filtering the AC voltage.
Resistance detection method. The method of claim 6,
Generating the feedback current,
Obtaining information about the size of the ripple using the converted voltage,
And generating the feedback current corresponding to the size of the ripple based on the obtained information but removing the ripple.
Resistance detection method. The method of claim 6,
Converting the physical signal to a digital signal,
Converting the digital signal,
And converting the DC voltage that has not been filtered into a digital signal and converting the AC voltage that has been filtered into a digital signal.
Resistance detection method. The method of claim 6,
The step of performing the filtering,
And performing the filtering using a band pass filter (BPF).
Resistance detection method.

Images