KR101991123B1 - Sensor device including ring oscillator cell - Google Patents

Abstract

The present invention relates to a sensor device having a ring oscillator cell which includes a plurality of nodes. The sensor device comprises: a sensing unit connected to at least one of the plurality of nodes; an output measurement unit measuring an output of the ring oscillator cell; and a control unit determining a change of at least one of a resistance and a capacitance of an object connected to the sensing unit based on a change of the output.

Description

[0001] The present invention relates to a sensor device including a ring oscillator cell,

The present invention relates to a sensor device comprising a ring oscillator cell.

MOS field-effect transistors are the most common field-effect transistors (FETs) in digital and analog circuits. Also called MOSFET (MOSFET) for short. The MOSFET is composed of an N-type semiconductor or a P-type semiconductor material channel, and a device having both a NMOSFET and a PMOSFET according to the material is used as a cMOSFET (complementary MOSFET) Classify. MOSFETs are used to make various kinds of devices.

A ring oscillator (oscillator) means an odd number of inverting amplifiers or a sequential logic circuit oscillator in which an inverter or a delay is connected in series in the form of a loop circuit. The ring oscillator is characterized by a separate input and output. Further, the ring oscillator has a simple structure and is widely used in an integrated circuit.

A typical ring oscillator consists of an odd number of inverters connected in series.

Registration Patent No. 10-1153911, May 31, 2012 Registration

A problem to be solved by the present invention is to provide a sensor device including a ring oscillator cell.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems which are not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a sensor device including a ring oscillator cell, wherein the ring oscillator cell includes a plurality of nodes, and the sensor device includes at least one of the plurality of nodes An output measuring unit for measuring an output of the ring oscillator cell, and a controller for determining at least one of a resistance and a capacitance of an object connected to the sensing unit based on a change in the output.

The ring oscillator cell may include at least one NAND gate, at least one inverter, and a power supply unit for applying a voltage to the NAND gate; And a first ring oscillator cell, including a first ring oscillator cell.

In addition, the ring oscillator cell may include at least one three-phase inverter, one or more inverters, and a power supply unit for applying a voltage to the three-phase inverter.

Further, the sensor device may further include a second ring oscillator cell including a plurality of inverters.

The sensor device further includes a plurality of the first ring oscillator cells and a plurality of the second ring oscillator cells, wherein the plurality of first ring oscillator cells and the plurality of second ring oscillator cells are connected in a fractal structure .

The sensing unit may include a first sensing unit used to determine a change in resistance of the object and a second sensing unit used to sense a change in capacitance of the object.

The first sensing unit may be connected between VDD and at least one of the plurality of nodes, and the second sensing unit may be connected between two nodes included in the plurality of nodes.

According to one aspect of the present invention, there is provided a sensor device including a ring oscillator cell, including: at least one three-phase inverter; at least one inverter; and a power source for applying a voltage to the three- An output measuring unit for measuring an output of the ring oscillator cell and an output measuring unit for measuring an output of the object connected to the sensing unit based on a change in the output of the at least one three-phase inverter and the at least one inverter, And a control unit for determining a resistance or a change in capacitance of the capacitor.

According to an aspect of the present invention, there is provided a sensor apparatus including a ring oscillator cell including a ring oscillator cell including at least one NAND gate, at least one inverter, and a power supply unit for applying a voltage to the NAND gate. A sensing unit coupled to at least one of the at least one NAND gate and the at least one inverter, an output measuring unit for measuring an output of the ring oscillator cell, and an output measuring unit for measuring a resistance of the object connected to the sensing unit, And a control unit for determining a change in capacitance.

Other specific details of the invention are included in the detailed description and drawings.

According to the disclosed embodiment, there is an effect that a sensor device capable of sensing the capacitance and voltage change of a circuit using a ring oscillator is provided.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 is a simplified illustration of a ring oscillator according to each embodiment.
2 is a diagram showing a structure of a ring oscillator using a NAND gate in a transistor unit according to an embodiment.
FIG. 3 is a diagram showing a structure of a ring oscillator using a three-phase inverter in a transistor unit according to an embodiment.
4 is a graph showing an experimental result using the ring oscillator shown in FIG. 2 and FIG. 3. FIG.
5 is a diagram illustrating a three-stage ring oscillator using a NAND gate according to an embodiment.
6 is a diagram illustrating a five-stage oscillator using a NAND gate according to one embodiment.
7 is a diagram illustrating a 7-stage oscillator using a NAND gate according to an embodiment.
8 is a diagram illustrating a 9-stage oscillator using a NAND gate according to an embodiment.
9 is a diagram illustrating a three-stage ring oscillator using a three-phase inverter according to an embodiment.
10 is a diagram illustrating a five-stage ring oscillator using a three-phase inverter according to an embodiment.
11 is a diagram illustrating a seven-stage ring oscillator using a three-phase inverter according to an embodiment.
12 is a diagram showing a nine-stage ring oscillator using a three-phase inverter according to an embodiment.
13 is a circuit diagram illustrating an experiment for applying a capacitance change to a single node according to an embodiment.
14 is a graph showing the output frequency change of the ring oscillator when the capacitance of the capacitor is changed in the circuit shown in Fig.
15 is a circuit diagram illustrating an experiment for applying a capacitance change to all nodes according to an embodiment.
16 is a graph showing the output frequency change of the ring oscillator when the capacitance of the capacitor is changed in the circuit shown in Fig.
17 is a diagram illustrating a circuit structure for an experiment of applying a resistance change to a single node according to an embodiment.
18 is a graph showing the output frequency change of the ring oscillator when the resistance is changed in the circuit shown in Fig.
19 is a diagram showing a circuit structure for an experiment of applying a resistance change to all nodes according to an embodiment.
20 is a graph showing the output frequency change of the ring oscillator when the resistance value of the resistor is changed in the circuit shown in Fig.
21 is a view showing a stacked ring oscillator according to an embodiment.
22 is a diagram illustrating a sensor device including a ring oscillator cell according to one embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, Is provided to fully convey the scope of the present invention to a technician, and the present invention is only defined by the scope of the claims.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms " comprises "and / or" comprising "used in the specification do not exclude the presence or addition of one or more other elements in addition to the stated element. Like reference numerals refer to like elements throughout the specification and "and / or" include each and every combination of one or more of the elements mentioned. Although "first "," second "and the like are used to describe various components, it is needless to say that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense that is commonly understood by one of ordinary skill in the art to which this invention belongs. In addition, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

As used herein, the term "part" or "module" refers to a hardware component, such as a software, FPGA, or ASIC, and a "component" or "module" performs certain roles. However, "part" or " module " is not meant to be limited to software or hardware. A "module " or " module " may be configured to reside on an addressable storage medium and configured to play back one or more processors. Thus, by way of example, "a" or " module " is intended to encompass all types of elements, such as software components, object oriented software components, class components and task components, Microcode, circuitry, data, databases, data structures, tables, arrays, and variables, as used herein. Or " modules " may be combined with a smaller number of components and "parts " or " modules " Can be further separated.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" And can be used to easily describe a correlation between an element and other elements. Spatially relative terms should be understood in terms of the directions shown in the drawings, including the different directions of components at the time of use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element . Thus, the exemplary term "below" can include both downward and upward directions. The components can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

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

1 is a simplified illustration of a ring oscillator according to each embodiment.

In one embodiment, the ring oscillator (oscillator) refers to a sequential logic circuit oscillator in which an odd number of inverting amplifiers or inverters or delay units are connected in series in the form of a loop circuit.

Referring to Figure 1 (a), a typical ring oscillator 100 including three inverters is shown.

The present invention aims at improving the power efficiency of a ring oscillator by controlling the oscillation and non-oscillation of a ring oscillator cell connected by a fextal structure. To this end, a NAND gate or a tri-state inverter .

For example, referring to FIG. 1 (b), a ring oscillator 100, which controls the oscillation and non-oscillation of the entire circuit by replacing one of the three inverters included in the ring oscillator 100 with a NAND gate 202, (200) are shown.

The ring oscillator 200 has the same structure as the ring oscillator 200 except that the output of the two inputs A and B of the NAND gate 202 is in the on state and the output is in the state B, And controls the oscillation and non-oscillation of the ring oscillator 200 by the NAND gate 202.

1C, a ring oscillator (not shown) for controlling the oscillation and non-oscillation of the entire circuit by replacing one of the three inverters included in the ring oscillator 100 with a three-phase inverter 302 300 are shown.

The output of the ring oscillator 300 is equal to B when the output of the three-phase inverter 302 is A and B of the input A is on. When the A is off, the output is in the Z-state floating state, the oscillation and non-oscillation states of the ring oscillator 300 are controlled by the three-phase inverter.

2 is a diagram showing a structure of a ring oscillator using a NAND gate in a transistor unit according to an embodiment.

Referring to FIG. 2, a NAND gate and two inverters are sequentially connected as shown in FIG. 1 (b). As a result of simulation using the ring oscillator 200, it was confirmed that oscillation occurs when en (enable voltage) = 0, and when oscillation occurs when en = 1.

FIG. 3 is a diagram showing a structure of a ring oscillator using a three-phase inverter in a transistor unit according to an embodiment.

Referring to FIG. 3, a three-phase inverter and two inverters are sequentially connected as shown in FIG. 1 (c). As a result of simulation using the ring oscillator 300, it was confirmed that oscillation occurs when en = 0, when oscillation occurs in a floating state, and when en = 1.

4 is a graph showing an experimental result using the ring oscillator shown in FIG. 2 and FIG. 3. FIG.

Referring to FIG. 4A, a change in frequency (in units of GHz) (vertical axis) according to change (horizontal axis) of en in the ring oscillator 200 shown in FIG. 2 is shown in a graph.

The results of measurement of the change in frequency according to the change in en in the ring oscillator 200 shown in FIG. 2 are shown in Table 1 below.

en [V] 2 2.25 2.5 2.75 3 frequency [GHz] 1.0547 1.1262 1.1628 1.184 1.1945

Similarly, referring to FIG. 4B, the frequency (frequency, in GHz unit) change (vertical axis) according to change (horizontal axis) of en in the ring oscillator 300 shown in FIG. 3 is shown in a graph.

The results of measurement of the change in frequency according to the change in en in the ring oscillator 3200 shown in FIG. 3 are shown in Table 2 below.

en [V] One 1.25 1.5 1.75 2 2.25 2.5 2.75 3 freq.
[GHz] 0.4623 0.8029 1.1268 1.2109 1.242 1.2595 1.2711 1.2791 1.2849

As shown in FIG. 4 and Table 1 and Table 2, as the enable voltage of both ring oscillators 200 and 300 increases, the oscillation frequency increases and the slope gradually decreases.

However, the ring oscillator 300 using the three-phase inverter has a wider frequency adjustment range than the ring oscillator 200 using the NAND gate, and oscillates at a lower enable voltage.

Therefore, the ring oscillator 300 using the three-phase inverter has an advantageous aspect for oscillation control of the ring oscillator.

FIGS. 5 to 12 are views each showing an example of controlling oscillation of an n-stage CON (Cellular Oscillatory Networks).

FIGS. 5 to 8 are views each showing an example of controlling oscillation of an n-stage CON using a NAND gate according to an embodiment.

5 is a diagram illustrating a three-stage ring oscillator using a NAND gate according to an embodiment.

Referring to FIG. 5, a three-stage ring oscillator 210 including six ring oscillators is shown. Also, at least a part of the six ring oscillators may be constituted by a ring oscillator 200 using a NAND gate as shown in Fig.

According to the non-limiting embodiment shown in FIG. 5, of the six ring oscillators, the three ring oscillators, shown in gray shades, are comprised of ring oscillators 200 using NAND gates. Therefore, among the total of 18 elements included in the three-stage ring oscillator 210, 15 inverters and three NAND gates, 16.67% of the NAND gates can be composed of NAND gates.

6 is a diagram illustrating a five-stage oscillator using a NAND gate according to one embodiment.

Referring to FIG. 6, a five-stage ring oscillator 220 including fifteen ring oscillators is shown. Further, at least a part of the fifteen ring oscillators may be constituted by a ring oscillator 200 using a NAND gate as shown in Fig.

According to the non-limiting embodiment shown in FIG. 6, of the fifteen ring oscillators, five ring oscillators, shown in gray shades, are comprised of ring oscillators 200 with NAND gates. Therefore, among the total of 45 elements included in the 5-stage ring oscillator 220, 40 inverters and 5 NAND gates, 11.11% of the NAND gates can be composed of NAND gates.

7 is a diagram illustrating a 7-stage oscillator using a NAND gate according to an embodiment.

Referring to FIG. 7, there is shown a seven-stage ring oscillator 230 comprising twenty-eight ring oscillators. Further, at least a part of the 28 ring oscillators may be constituted by a ring oscillator 200 using a NAND gate as shown in Fig.

According to the non-limiting embodiment shown in FIG. 7, seven of the 28 ring oscillators, shown in gray shades, are comprised of ring oscillators 200 with NAND gates. Therefore, among the 84 elements included in the 7-stage ring oscillator 230, there are 77 inverters and 7 NAND gates, and 8.33% of the NAND gates can be composed of NAND gates.

8 is a diagram illustrating a 9-stage oscillator using a NAND gate according to an embodiment.

Referring to FIG. 8, a nine-stage ring oscillator 240 including 45 ring oscillators is shown. Also, at least a part of the 45 ring oscillators may be composed of a ring oscillator 200 using a NAND gate as shown in FIG.

According to the non-limiting embodiment shown in FIG. 8, twelve ring oscillators, shown in gray shades among the 45 ring oscillators, are comprised of ring oscillators 200 using NAND gates. Therefore, among the total of 135 elements included in the 9-stage ring oscillator 240, 123 inverters and NAND gates are 12, and 8.89% of the NAND gates can be composed of NAND gates.

FIGS. 9 to 12 are views each showing an example of controlling oscillation of an n-stage CON using a three-phase inverter according to an embodiment.

9 is a diagram illustrating a three-stage ring oscillator using a three-phase inverter according to an embodiment.

Referring to FIG. 9, a three-stage ring oscillator 310 including six ring oscillators is shown. Also, at least a part of the six ring oscillators may be composed of a ring oscillator 300 using a three-phase inverter as shown in Fig.

According to the non-limiting embodiment shown in FIG. 9, the three ring oscillators, shown in gray shades among the six ring oscillators, are comprised of a ring oscillator 300 using a three-phase inverter. Therefore, among the total of 18 elements included in the three-stage ring oscillator 310, 15 inverters and 3-phase inverters can be constituted by 3-phase inverters, 16.67% of the total.

10 is a diagram illustrating a five-stage ring oscillator using a three-phase inverter according to an embodiment.

Referring to FIG. 10, a five-stage ring oscillator 320 including fifteen ring oscillators is shown. Also, at least a part of the fifteen ring oscillators may be constituted by a ring oscillator 300 using a three-phase inverter as shown in Fig.

According to the non-limiting embodiment shown in FIG. 10, six of the fifteen ring oscillators, shown in gray shades, are comprised of a ring oscillator 300 using a three-phase inverter. Therefore, 39 out of the 45 elements included in the five-stage ring oscillator 320, and 3-phase inverter 6, 13.33% of the total can be configured as a three-phase inverter.

11 is a diagram illustrating a seven-stage ring oscillator using a three-phase inverter according to an embodiment.

Referring to FIG. 11, there is shown a seven-stage ring oscillator 330 that includes 28 ring oscillators. In addition, at least a part of the 28 ring oscillators may be constituted by a ring oscillator 300 using a three-phase inverter as shown in Fig.

According to the non-limiting embodiment shown in FIG. 11, the nine ring oscillators, shown in gray shades among the 28 ring oscillators, are comprised of a ring oscillator 300 using a three-phase inverter. Therefore, among the total 84 elements included in the 7-stage ring oscillator 330, there are 75 inverters and 9-phase inverters, and 10.71% of the total can be composed of 3-phase inverters.

12 is a diagram showing a nine-stage ring oscillator using a three-phase inverter according to an embodiment.

Referring to FIG. 12, a nine-stage ring oscillator 340 including 45 ring oscillators is shown. In addition, at least a part of the 45 ring oscillators may be constituted by a ring oscillator 300 using a three-phase inverter as shown in Fig.

According to the non-limiting embodiment shown in FIG. 12, twelve ring oscillators, shown in gray shades among the 45 ring oscillators, are comprised of a ring oscillator 300 using a three-phase inverter. Accordingly, among the total 135 elements included in the 9-stage ring oscillator 340, 123 inverters and 12-phase inverters, 8.89% of the total can be composed of three-phase inverters.

13 to 16 are diagrams for explaining a change in oscillation frequency according to a capacitance change of a ring oscillator according to an embodiment.

The ring oscillators 400 and 500 shown in Figs. 13 and 15 are circuits composed of three inverters, as shown in Fig. 1 (a). However, the ring oscillators 400 and 500 are not limited to those shown in Figs. 13 and 15, and the circuits shown in Figs. 1 (b) and 1 (c) The illustrated circuit may be used, or a ring oscillator circuit of another configuration may be used.

13 is a circuit diagram illustrating an experiment for applying a capacitance change to a single node according to an embodiment.

Referring to FIG. 13, a capacitor is added to one node of the ring oscillator 400. For example, a capacitor may be added between the first inverter and the second inverter of the ring oscillator 400. [ This is added to test the change in capacitance due to external stimulation. When the change in capacitance due to external stimulation is actually sensed by using the ring oscillator 400, Can be connected to the position of the stationary.

14 is a graph showing the output frequency change of the ring oscillator when the capacitance of the capacitor is changed in the circuit shown in Fig.

For example, the capacitance can be varied from 0% to 10% (step: 1%) and 10% to 30% (step: 10%) with respect to the gate capacitance of the MOSFET. The results of the change in capacitance are shown in Table 3 below.

capacitance change rate [%] 0 One 2 3 4 5 6 frequency [GHz] 1.4742 1.4738 1.4733 1.4728 1.4724 1.4719 1.4715 capacitance change rate [%] 7 8 9 10 20 30 - frequency [GHz] 1.4710 1.4705 1.4701 1.4696 1.4651 1.4606 -

When the capacitance changes in the ring oscillator (400) circuit, the output is represented by a change in frequency. Referring to FIG. 14 and Table 3, there is shown a variation of the output frequency according to a constant ratio capacitance change with respect to the gate capacitance.

It is confirmed that the frequency linearly decreases as the capacitance increases, and the frequency reduction can be expressed by the following equation (1).

Where f is the output frequency of the ring oscillator 400, C is the rate of capacitance change due to external stimuli relative to the gate capacitance, and y intercept 1.4742 is the output when there is no capacitance due to external stimuli Frequency.

From this, Equation (1) can be summarized as Equation (2) below.

15 is a circuit diagram illustrating an experiment for applying a capacitance change to all nodes according to an embodiment.

Referring to FIG. 15, capacitors are added to all the nodes of the ring oscillator 400. For example, the capacitors may be added between all the inverters of the ring oscillator 400, respectively. This is added to test the change in capacitance due to external stimulation. When the change in capacitance due to external stimulation is actually sensed by using the ring oscillator 400, May be respectively connected to the positions of the persisances.

16 is a graph showing the output frequency change of the ring oscillator when the capacitance of the capacitor is changed in the circuit shown in Fig.

For example, the capacitance can be varied from 0% to 10% (step: 1%) and 10% to 30% (step: 10%) with respect to the gate capacitance of the MOSFET. When all the capacitors have the same capacitance change, the results according to the capacitance change are shown in Table 4 below.

capacitance change rate [%] 0 One 2 3 4 5 6 frequency [GHz] 1.4742 1.4728 1.4715 1.4701 1.4686 1.4672 1.4658 capacitance change rate [%] 7 8 9 10 20 30 - frequency [GHz] 1.4644 1.4630 1.4616 1.4602 1.4462 1.4322 -

When the capacitance changes in the ring oscillator (500) circuit, the output is represented by a change in frequency. Referring to FIG. 16 and Table 4, there is shown a variation of the output frequency according to a constant ratio capacitance change with respect to the gate capacitance.

It is confirmed that the frequency linearly decreases as the capacitance increases, and the frequency decrease can be expressed by the following equation (3).

Compared with Equation (1), it is confirmed that only the proportional coefficient for the capacitance is increased about three times.

Further, different capacitances can be given to three nodes in the circuit shown in Fig. The experimental results are shown in Table 5 below when different capacitances are given to the three nodes.

capacitance change rate [%] frequency [GHz] ca: 1% cb: 3% cc: 5% 1.4701 ca: 1% cb: 5% cc: 9% 1.4673 ca: 10% cb: 20% cc: 30% 1.4463

Table 5 shows the output frequency when three nodes are given a capacitance change of 2% step, 4% step and 10% step, respectively, compared to the MOSFET gate capacitance. As shown in Fig. 16, when the capacitances of the entire circuits are compared with each other, the waveforms shown in Fig. 16 are outputted because the capacitors have different capacitances.

Therefore, when the capacitance of the ring oscillator circuit is experimented by varying the capacitance value according to the disclosed embodiment, the output frequency is linearly decreased as the capacitance value increases as shown in Equation (4) below according to the capacitance value .

In Equation (4), N is the number of capacitors included in the ring oscillator.

Therefore, when a capacitance change occurs on a circuit due to an external stimulus, an external stimulus can be sensed by changing the oscillation frequency of the ring oscillator. As a result, it can be seen that the ring oscillator can be used not only as a simple oscillation circuit but also as a sensor circuit capable of sensing a substance that affects the capacitance of the entire circuit by making contact with the circuit.

FIGS. 17 to 20 are diagrams for explaining the change of the oscillation frequency according to the resistance change of the ring oscillator according to an embodiment. FIG.

The ring oscillators 600 and 700 shown in Figs. 17 and 19 are circuits composed of three inverters, as shown in Fig. 1 (a). However, the ring oscillators 600 and 700 are not limited to those shown in Figs. 17 and 19, and the circuits shown in Figs. 1 (b) and 1 (c) The illustrated circuit may be used, or a ring oscillator circuit of another configuration may be used.

17 is a diagram illustrating a circuit structure for an experiment of applying a resistance change to a single node according to an embodiment.

Referring to FIG. 17, a resistance is added to one node of the ring oscillator 600. For example, a resistor may be added between the first inverter of the ring oscillator 600 and VDD. This is added to test the resistance change due to external stimulation. When the change of capacitance due to external stimulation is actually sensed by using the ring oscillator 600, the external stimulation element may have a capacitance Lt; / RTI >

18 is a graph showing the output frequency change of the ring oscillator when the resistance is changed in the circuit shown in Fig.

For example, the resistance can be varied from 0k to 10k (step: 1k) and from 10k to 30k (step: 10k). The results of the resistance change are shown in Table 6 below.

Resistance [Ω] 0 1k 2k 3k 4k 5k 6k frequency [GHz] 1.4742 1.4309 1.3929 1.3591 1.3286 1.3008 1.2752 resistance [Ω] 7k 8k 9k 10k 20k 30k - frequency [GHz] 1.2515 1.2294 1.2087 1.1891 1.0362 0.9284 -

When the resistance is changed in the ring oscillator 600 circuit, the output is represented by a change in frequency. Referring to FIG. 18 and Table 6, a change in the output frequency according to the resistance change is shown. According to this, it is confirmed that as the resistance increases, the output frequency decreases and the slope thereof also decreases.

19 is a diagram showing a circuit structure for an experiment of applying a resistance change to all nodes according to an embodiment.

Referring to FIG. 19, a resistance is added to all nodes of the ring oscillator 700. For example, a resistor may be added between each inverter of the ring oscillator 700 and VDD, respectively. This is added to test the resistance change due to the external stimulation. When the resistance change due to the external stimulation is actually sensed using the ring oscillator 700, the external stimulation element is placed at the position of the resistor shown in FIG. 19 Can be connected.

20 is a graph showing the output frequency change of the ring oscillator when the resistance value of the resistor is changed in the circuit shown in Fig.

For example, resistances can be varied equally between 0k and 10k (step: 1k) and between 10k and 30k (step: 10k). The results of the resistance change are shown in Table 7 below.

resistance [Ω] 0 1k 2k 3k 4k 5k 6k frequency [GHz] 1.4742 1.3591 1.2669 1.1911 1.1273 1.0728 1.0254 resistance [Ω] 7k 8k 9k 10k 20k 30k - frequency [GHz] 0.9835 0.9469 0.9140 0.8857 0.6968 0.6026 -

20 and Table 7 are graphs and a result table for the output frequency change of the ring oscillator 700 when the same resistance change is given to all the inverters. Experimental results show that the output frequency is reduced about three times faster than when the resistance is changed to a single node.

Further, in the circuit shown in Fig. 19, different resistance changes can be given to the three nodes. The experimental results are shown in Table 8 below when different resistance changes are given to the three nodes.

resistance [Ω] frequency [GHz] a: 1k b: 2k c: 3k 1.2047 a: 1k b: 5k c: 9k 1.0957 a: 10k b: 20k c: 30k 0.7011

Table 8 shows the output frequency when the resistance changes of 1k step, 4k step and 10k step are applied to three inverters, respectively.

It was confirmed that a waveform having a frequency approximate to that of Fig.

Therefore, it is confirmed that the ring oscillator circuit can be decomposed into the sensor circuit because the output changes according to the change of the resistance value.

That is, when a resistance change occurs on a circuit due to an external stimulus, an external stimulus can be sensed by changing the oscillation frequency of the ring oscillator due to the influence of the resistance change. As a result, it can be seen that the ring oscillator can be used not only as a simple oscillation circuit but also as a sensor circuit capable of sensing a substance that affects the resistance of the entire circuit by making contact with the circuit.

In addition, specific details of the relationship between the change in resistance value and other output frequencies and the specification of how to detect a specific object when stimulation occurs at the same time as the change in capacitance can be used as a more accurate and efficient sensor device have.

21 is a view showing a stacked ring oscillator according to an embodiment.

Referring to FIG. 21, there is shown a simple stacked ring oscillator 810-830 in which one or more CONs are simply stacked without change in orientation.

This is a structure that simply connects in-phase nodes, so that it is not a problem to output the oscillation waveform. It was confirmed that the frequency also appeared to be the same (for example, 1.4742 GHz).

In another embodiment, in the case of a composite stacked ring oscillator stacked upside down with respect to the direction of a portion of CON, different results are obtained with forward and reverse mixing.

For example, in a stacked ring oscillator structure in which forward and reverse directions are mixed, oscillation does not occur at even stages (2 stages, 4 stages, ..., 2n stages) and odd stages (3 stages, 5 stages, ..., 2n- ), It was confirmed that a rash occurred.

Also, it has been confirmed that the oscillation frequency is greatly reduced when two or more pairs of opposite direction components are formed in the odd-numbered stages.

That is, it is confirmed that the forward direction and the reverse direction CON are canceled as the respective oscillation signals are synthesized.

In the case of a ring oscillator with a stacked structure, it can be used to fabricate a chip in a 3D structure. In this process, voltage drop due to a power line and an interlayer distance, heat generation control by a difference in distance between the heat sink and each layer, And the resistance of the vias connecting the layers.

For example, when it is judged that the difference in distance between the layers is small and a problem is caused in the control of the heat generation, the respective oscillation signals can be canceled by laminating ring oscillators opposite to each other in the layer. Conversely, when the distance difference between the layers is wide, ring oscillators in the same direction may be stacked, but the present invention is not limited thereto.

22 is a diagram illustrating a sensor device including a ring oscillator cell according to one embodiment.

Referring to FIG. 22, the sensor device 900 includes a ring oscillator cell 910. In one embodiment, the ring oscillator cell 910 includes a plurality of nodes 912, 914, and 916.

In one embodiment, the sensor device 900 includes a sensing portion 920 coupled to at least one of a plurality of nodes 912,914, and 916 (e.g., 912). For example, the sensing unit may have a structure in which one end is connected to at least one node 912 and the other end is connected to an external circuit or the like. For example, the sensing unit 920 may include a connecting member such as a wire connecting two points of the node 912 and two points of the external circuit.

In one embodiment, the sensing unit 920 may include a first sensing unit used to determine a change in resistance of an external object and a second sensing unit used to sense a change in capacitance of the external object .

For example, the first sensing unit is connected between VDD and at least one of the plurality of nodes 912, 914, and 916 included in the ring oscillator cell 910, and the second sensing unit includes a plurality of nodes 912, 914, and 916 ). ≪ / RTI >

For example, the sensing portion 920 may be connected to the positions of the capacitors and resistors shown in Figs. 17 and 19. That is, instead of the capacitors and resistors shown in FIGS. 17 and 19, two points for sensing the change in capacitance or resistance may be connected to the sensing unit 920.

The sensing part connected to the position of the capacitor shown in Fig. 17 is used for judging a change in capacitance, and the sensing part connected to the position of the resistance shown in Fig. 19 can be used for judging a change in resistance.

In one embodiment, the sensor device 900 includes an output measuring portion 930 that measures the output of the ring oscillator cell 910. The output measuring unit 930 measures an oscillation frequency generated in the ring oscillator cell 910 and determines a change in capacitance and resistance of an external circuit connected to the sensing unit 920.

The control unit 940 may refer to a computing device that includes at least one processor and may refer to a circuit capable of performing operations in accordance with the disclosed embodiments. In the disclosed embodiment, the control unit 940 determines a change in at least one of the resistance and the capacitance of the object connected to the sensing unit 920 based on a change in the output measured from the output sensing unit 930.

In one embodiment, the ring oscillator cell 910 may include at least one NAND gate, one or more inverters, and a power supply for applying a voltage to the NAND gate.

For example, one NAND gate and one of two inverters may be disposed in each of the nodes 912, 914, and 916 shown in FIG. 22, but is not limited thereto. For example, the left ring oscillator 200 shown in FIG. 2 may be utilized as the ring oscillator cell 910.

In one embodiment, the ring oscillator cell 910 may include at least one three-phase inverter, one or more inverters, and a power supply for applying voltage to the three-phase inverter.

For example, each of the nodes 912, 914, and 916 shown in FIG. 22 may be provided with one of a three-phase inverter and one of two inverters, but is not limited thereto. For example, the ring oscillator 300 shown in FIG. 3 may be utilized as the ring oscillator cell 910.

In one embodiment, the sensor device 900 may further include a ring oscillator cell (not shown) including a plurality of inverters. For example, the ring oscillator cell may include, but is not limited to, three inverters.

In the disclosed embodiment, a plurality of ring oscillator cells including a NAND gate or a three-phase inverter and a plurality of ring oscillator cells including three inverters may be connected to each other in a fractal structure to configure the sensor device 900, But is not limited thereto.

In one embodiment, the sensor device 900 may include a ring oscillator cell 910 that includes at least one three-phase inverter, one or more inverters, and a power supply that applies a voltage to the three-phase inverter.

The sensor device 900 also includes a sensing portion 920 connected to at least one of the three-phase inverter and one or more inverters, an output measuring portion 930 for measuring the output of the ring oscillator cell 910, And a controller 940 for determining resistance or capacitance change of the object connected to the sensing unit 920 based on the change of the output.

In one embodiment, the sensor device 900 may include a ring oscillator cell 910 that includes at least one NAND gate, one or more inverters, and a power supply for applying a voltage to the NAND gate.

The sensor device 900 also includes a sensing unit 920 coupled to at least one of the NAND gate and the at least one inverter, an output measurement unit 930 for measuring the output of the ring oscillator cell 910, And a controller 940 for determining a change in resistance or capacitance of an object connected to the sensing unit 920 based on the change of the resistance or the capacitance.

21, a ring oscillator of a stacked structure in which a plurality of ring oscillator cells are stacked can be used in the sensor device 900. [

In one embodiment, the change in output frequency with changes in capacitance is linear, as shown in Figs. 14 and 16. Fig.

In one embodiment, the change of the output frequency with the change of the resistance is nonlinear, and it is confirmed that the frequency increases with the increase of the resistance as shown in Figs. 18 and 20, and the slope thereof becomes smaller. Therefore, in the case of measuring the change in resistance, not only the change amount of the frequency but also the slope thereof can be considered together.

In addition, when the resistance and the capacitance change at the same time, it is possible to use the fact that the change of the output frequency due to the change of the resistance and the capacitance is different from each other in order to detect the change in the output frequency.

For example, if the output frequency changes, the amount of change in capacitance is calculated assuming that the change is due to a change in capacitance, and similarly, the amount of change in resistance is calculated assuming that the change is due to a change in resistance . The slope of each variation is obtained from the calculation result, and it can be seen that the change of the capacitance has more influence when the slope is close to the linear variation, and when the slope is close to the nonlinear variation, It can be seen that it has affected.

Therefore, the ratio of the change amount of the resistance and the capacitance can be calculated based on the change amount of the gradient according to the result of each calculation, and the change amount of the resistance and the capacitance can be calculated therefrom.

Further, since the sensing portions used for measuring the resistance and the capacitance are arranged at different places, the resistance and the variation of the capacitance can be individually calculated by alternately using the sensing portions.

The steps of a method or algorithm described in connection with the embodiments of the present invention may be embodied directly in hardware, in software modules executed in hardware, or in a combination of both. The software module may be a random access memory (RAM), a read only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a hard disk, a removable disk, a CD- May reside in any form of computer readable recording medium known in the art to which the invention pertains.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

900: Sensor device
910: Ring oscillator cell
912: Node
914: Node
916: Node
920:
930: Output measuring unit
940:

Claims (9)

A sensor device comprising a ring oscillator cell,
The ring oscillator cell comprising a plurality of nodes,
A sensing unit connected to at least one of the plurality of nodes;
An output measuring unit for measuring an output of the ring oscillator cell; And
And a control unit for determining at least one of a resistance and a capacitance of an external circuit connected to the sensing unit based on a change in the output,
The sensing unit includes:
A first sensing unit used to determine a change in resistance of the external circuit; And
A second sensing unit used to sense a change in capacitance of the external circuit; . The method according to claim 1,
The ring oscillator cell comprises:
At least one NAND gate;
One or more inverters; And
A power supply unit for applying a voltage to the NAND gate; A first ring oscillator cell; . The method according to claim 1,
The ring oscillator cell comprises:
At least one three-phase inverter;
One or more inverters; And
A power supply unit for applying a voltage to the three-phase inverter; A first ring oscillator cell; . The method according to claim 2 or 3,
A second ring oscillator cell including a plurality of inverters; Further comprising: 5. The method of claim 4,
The sensor device includes:
A plurality of said first ring oscillator cells; And
A plurality of said second ring oscillator cells; / RTI >
Wherein the plurality of first ring oscillator cells and the plurality of second ring oscillator cells are connected in a fractal structure. delete The method according to claim 1,
Wherein the first sensing unit is connected between VDD and at least one of the plurality of nodes,
And the second sensing unit is connected between two nodes included in the plurality of nodes. At least one three-phase inverter;
One or more inverters; And
A power supply unit for applying a voltage to the three-phase inverter;
A ring oscillator cell;
A sensing unit coupled to at least one of the at least one three-phase inverter and the at least one inverter;
An output measuring unit for measuring an output of the ring oscillator cell; And
A control unit for determining a resistance or a capacitance change of an external circuit connected to the sensing unit based on a change in the output; Lt; / RTI >
The sensing unit includes:
A first sensing unit used to determine a change in resistance of the external circuit; And
A second sensing unit used to sense a change in capacitance of the external circuit; And a ring oscillator cell. At least one NAND gate;
One or more inverters; And
A power supply unit for applying a voltage to the NAND gate;
A ring oscillator cell;
A sensing unit coupled to at least one of the at least one NAND gate and the at least one inverter;
An output measuring unit for measuring an output of the ring oscillator cell; And
A control unit for determining a resistance or a capacitance change of an external circuit connected to the sensing unit based on a change in the output; Lt; / RTI >
The sensing unit includes:
A first sensing unit used to determine a change in resistance of the external circuit; And
A second sensing unit used to sense a change in capacitance of the external circuit; And a ring oscillator cell.

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