TWI551048B - Linear triangular wave generator with stray effect compensation and associated method for compensating stray effect - Google Patents

Description

Linear triangular wave generator with spurious effect compensation and compensation method for spurious effect

The invention relates to a triangular wave generator, in particular to a linear triangular wave generator with spurious effect compensation and a method for compensating the same.

The constant linear ramp generator or triangular wave signal generator charges the capacitor with a constant current source, and the output signal is compared with the reference voltage on the comparator, and then the signal of the output of the comparator is obtained, and then the current source is switched. However, the non-ideality of the process, such as spurious effects, offset effects, etc., will affect the linearity of the process signal.

Conventional methods for removing spurious effects, such as Lin Junwei et al., "Linearity enhancement technique of ramp generator for ADC testing", published in the journal IEICE Electronics Express, include a current source, a physical capacitor, a capacitive stray component, and a negative impedance. The converter uses the current source to charge and discharge the solid capacitor to generate a signal and the capacitive stray component causing a spurious effect, and designing a negative impedance matching the capacitive stray component on the negative impedance converter The impedance is matched to compensate for this spurious effect.

The negative matching impedance is obtained based on the fact that one of the negative impedance converters is ideal. However, the operational amplifier is not ideal in reality, and the negative matching impedance is inaccurate and cannot be mixed with the capacitor. The components are matched so that the output signal is not linear. Therefore, how to further calibrate the negative matching impedance and output the linear signal is the goal of the related industry.

The main object of the present invention is to solve the problem that the negative matching impedance is inaccurate and cannot be matched with the capacitive stray element, thereby making the output signal non-linear.

To achieve the above objective, the present invention provides a linear triangular wave generator with spurious effect compensation, comprising a linear triangular wave generating module, a negative impedance converting module, an impedance sensing module and a switching module, the linear The triangular wave generating module includes a first current source and a physical capacitor and a stray component electrically connected to the first current source, and the stray component is generated by a stray effect of the first current source and the solid capacitor, The first current source charges and discharges the solid capacitor to generate a linear triangular wave signal. The negative impedance conversion module is electrically connected to the linear triangular wave generating module, and includes a negative matching that compensates the impedance of the stray component. The impedance module is electrically connected to the negative impedance conversion module and the impedance sensing module, and includes a first switching state and a second switching for switching the sensing configuration of the impedance sensing module. a state for the impedance sensing module to sense the degree of matching of the negative matching impedance with the impedance of the stray element.

To achieve the above object, the present invention further provides a method for compensating for spurious effects of a linear triangular wave generator, which comprises the following steps:

S1: charging and discharging a solid capacitor by using a first current source in a linear triangular wave generating module to generate a triangular wave signal, and the linear triangular wave generating module further has a stray component generated by a spurious effect;

S2: design a negative matching impedance matched to the stray element in a negative impedance conversion module;

S3: electrically connecting the negative impedance conversion module to the first current source and parallel to the physical capacitor, and compensating the impedance of the stray component by the negative matching impedance;

S4: sensing, by using an impedance sensing module, a matching degree of the negative matching impedance and an impedance of the stray component;

S5: electrically connecting a switching module to the negative impedance conversion module and the impedance sensing module, including a first switching state and a second switching for switching a sensing configuration of the impedance sensing module a state for the impedance sensing module to sense the degree of matching of the negative matching impedance with the impedance of the stray element;

S6: Adjust the value of the negative matching impedance according to the sensing result of the impedance sensing module to output a linear triangular wave signal.

As can be seen from the above, the present invention compensates for the spurious effect caused by the stray component by the negative matching impedance in the negative impedance conversion module, and further utilizes the impedance sensing module to sense the negative matching impedance. The degree of matching with the impedance of the stray element is adjusted according to the sensing result of the impedance sensing module to output the linear triangular wave signal.

The detailed description and technical content of the present invention will now be described as follows:

Please refer to FIG. 1 , which is a schematic circuit diagram of the present invention. The circuit includes a linear triangular wave generating module 10 , a negative impedance converting module 20 , an impedance sensing module 30 , and a switching module 40 . The triangular wave generating module 10 is electrically connected to the negative impedance converting module 20 , and the switching module 40 is electrically connected to the negative impedance converting module 20 and the impedance sensing module 30 . The linear triangular wave generating module 10 includes a first current source 11 , a physical capacitor 12 , a stray component 13 , a clock switching unit 14 , and a window type comparing unit 15 . The clock switching unit 14 is electrically connected to the a first current source 11 and the physical capacitor 12, and controlling the first current source 11 to charge and discharge the solid capacitor 12, and output a triangular wave signal, when the CLK switch forms a path, When the switch forms an open circuit, it is in a charging state, and vice versa, when the CLK switch forms an open circuit, When the switch forms a path, it is in a discharge state, and the stray element 13 is generated due to the stray effect of the first current source 11 and the solid capacitor 12, and the stray element 13 further includes a capacitor 12 a capacitive stray element 131 and a first current source stray element 132 generated by the first current source 11 , the window type comparing unit 15 is electrically connected to the first current source 11 and connected to the physical capacitor 12 , The clock switching unit 14 performs charging and discharging according to the control of the window type comparing unit 15 to control the upper and lower limits of the output of the triangular wave signal.

The negative impedance conversion module 20 is electrically connected to the linear triangular wave generation module 10, and includes a negative matching impedance 21, a first operational amplification unit 22, a first resistor 23, and a second resistor 24. The operational amplifier unit 22 includes a first inverting input terminal 221 , a first non-inverting input terminal 222 , and a first output terminal 223 . The first non-inverting input terminal 222 is electrically connected to the first current source 11 . The first output end 223 is electrically connected to the switching module 40. The two ends of the first resistor 23 are electrically connected to the first inverting input terminal 221 and the switching module. The two ends of the second resistor 24 are electrically connected to the first inverting input end 221 and a ground end. The two ends of the negative matching impedance 21 are electrically connected to the first non-inverting input end 222 respectively. And the switching module 40. The impedance of the stray element 13 can be compensated by the setting of the negative matching impedance 21, so that the spurious effect does not affect the circuit, but the first operational amplification is performed during the implementation of the negative impedance conversion module 20. The unit 22 is not ideal, and the influence of the non-ideality of the process cannot be avoided. Therefore, in order to further improve the accuracy, the impedance sensing module 30 is connected to perform secondary adjustment. The negative matching impedance 21 has a capacitance negative matching impedance 211 corresponding to the capacitive stray element 131 and a first current source negative matching impedance 212 corresponding to the first current source stray element 132.

The switching module 40 is electrically connected to the negative impedance conversion module 20 and the impedance sensing module 30, and includes a first switching state for switching the sensing configuration of the impedance sensing module 30 and a The second switching state is used by the impedance sensing module 30 to sense the matching degree of the capacitance negative matching impedance 211 and the impedance of the stray element 13. The impedance sensing module 30 includes a second operational amplifying unit 31, an inverting unit 32, a first switch 33, a second switch 34, a first capacitor 35, a second capacitor 36, and a first a second current source 37, the second operational amplifier unit 31 includes a second inverting input terminal 311, a second non-inverting input terminal 312, and a second output terminal 313. The second non-inverting input terminal 312 is electrically Connected to the switching module 40, the two ends of the first switch 33 are electrically connected to the second output end 313 and the first capacitor 35, and the first capacitor 35 is electrically connected to one end of the first switch 33. The two ends of the second switch 34 are electrically connected to the negative matching impedance 21 and the second output end 313, and the two ends of the second capacitor 36 are electrically connected to the second non-inverting input terminal 222. The switching module 40 and the first non-inverting input terminal 222 are electrically connected to the second output terminal 313 and the second current source 37. The inverting unit 32 controls the second current source 37. The impedance sensing module 30 is charged and discharged in the forward and reverse directions. In this embodiment, the second current source 37 is As a way of example, it may be two, respectively, the actual charging and discharging operation.

When the switching module 40 is switched to the first switching state, the first output end 223 of the first operational amplifying unit 22 and the second non-inverting input end 312 of the second operational amplifying unit 31 are electrically connected to The second capacitor 36 is configured to: when the switching module 40 is switched to the second switching state, the first output end 223 of the first operational amplifying unit 22 and the second non-inverting input of the second operational amplifying unit 31 The terminal 312 is electrically connected to the first resistor 23 and the negative matching impedance 21 . And when When the path is formed and CK1 is broken, the impedance sensing module 30 senses the degree of matching between the negative matching impedance 21 and the impedance of the stray element 13, and conversely, compensates the impedance of the stray element 13.

Continued collocation refers to "FIG. 2A" to "FIG. 2E", which is a control method of the four sensing configurations of the impedance sensing module 30 and a circuit diagram thereof. When the switching module 40 is switched to the first switching state, the first switch 33 is connected, and the second switch 34 is not connected, a first configuration 50 is formed, and a first signal period is generated; when the switching mode is When the group 40 is switched to the first switching state, the first switch 33 is not connected, and the second switch 34 is connected, a second configuration 51 is formed, and a second signal period is generated; when the switching module 40 is switched to The second switching state, the first switch 33 is connected, and the second switch 34 is not connected, forming a third configuration 52, and generating a third signal period; when the switching module 40 switches to the first switching When the first switch 33 and the second switch 34 are not connected, a fourth configuration 53 is formed and a fourth signal period is generated. The first signal period, the second signal period, the third signal period, and the fourth signal period are analyzed by considering the non-ideal conditions of the first operational amplification unit 22 by switching between four configurations. As a result of obtaining the degree of matching between the negative impedance matching impedance 211 of the capacitor and the impedance of the stray element 13, the capacitance negative matching impedance 211 can be further calibrated. In this embodiment, the ability to compensate for spurious effects is enhanced. The negative matching impedance 211 of the capacitor is adjusted by using a computer simulation, and is directly formed by an internal connection during the production process. If the direct implementation is adjusted, the capacitor is negatively matched to the impedance 211. A linear triangular wave signal is output by adjusting the capacitor to negatively match the impedance 211.

In this embodiment, the first signal period can be expressed as:

The second signal period can be expressed as:

The third signal period can be expressed as:

The fourth signal period can be expressed as:

Wherein, R _x and C _x are impedance values of the capacitor negative matching impedance 211, I is an input current, C _{1 is} the first capacitor 35, and V _{1 is} an output voltage of the impedance sensing module 30, and t _d is The delay time of the first operational amplification unit 22 and the second operational amplification unit 31.

The first signal period, the second signal period, the third signal period, and the fourth signal period are analyzed and calculated, and the impedance value of the capacitor negative matching impedance 211 can be further determined, and can be expressed as: The capacitor negative matching impedance 211 is replaced by this adjustment.

Referring to FIG. 3 for further description, the present invention further discloses a method for compensating for spurious effects, which includes the following steps:

S1: charging and discharging a physical capacitor 12 by using a first current source 11 in a linear triangular wave generating module 10 to generate a triangular wave signal, and thus generating a stray element 13 generated by a spurious effect. The dispersing element 13 includes a capacitive stray element 131 generated by the solid capacitor 12 and a first current source stray element 132 generated by the first current source 11. To further illustrate the method for generating the triangular wave signal by the linear triangular wave generating module 10, the following steps are further included in the step S1:

S1A: controlling the first current source 11 to charge and discharge the physical capacitor 12 by using a clock switching unit 14, when the CLK switch forms a path, When the switch forms an open circuit, it is in a charging state, and vice versa, when the CLK switch forms an open circuit, When the switch forms a path, it is in a discharged state, and the triangular wave signal is generated.

S1B: The upper and lower limits of the output of the triangular wave signal are controlled by a window type comparing unit 15, and the clock switching unit 14 is controlled to perform charging and discharging according to the upper and lower limits of the output.

S2: Calculating a negative matching impedance 21 matched with the stray element 13 and electrically connecting with a first resistor 23, a second resistor 24, and a first operational amplifying unit 22 to form a negative impedance converting mode. Group 20.

S3: the negative impedance conversion module 20 is electrically connected to the first current source 11 and connected in parallel to the physical capacitor 12, when the CK1 switch forms a path, When the switch forms an open circuit, the negative matching impedance 21 compensates the impedance of the stray element 13;

S4: electrically connecting a second operational amplifying unit 31, an inverting unit 32, a first switch 33, a second switch 34, a first capacitor 35, a second capacitor 36, and a second current source 37. Forming an impedance sensing module 30, and sensing the impedance value of the negative impedance matching impedance 211 by using the impedance sensing module 30;

S5: The switch module 40 is electrically connected to the negative impedance conversion module 20 and the impedance sensing module 30, and includes a first switching state and a second switching state, and the first switch 33 and the first The second switch 34 switches the sensing mode of the impedance sensing module 30 for the impedance sensing module 30 to sense the matching degree of the capacitance negative matching impedance 211 and the impedance of the capacitive stray element 131.

Wherein, in step S5, the following steps are further included for sensing:

S5A: as shown in FIG. 2B, the switching module 40 is switched to the first switching state, the first switch 33 forms a path, and the second switch 34 forms an open circuit, so that the impedance sensing module 30 forms a first Configuring 50 and generating a first signal period;

S5B: as shown in FIG. 2C, the switching module 40 is switched to the first switching state, the first switch 33 forms an open circuit, and the second switch 34 forms a path, so that the impedance sensing module 30 forms a second Configuring 51 and generating a second signal period;

S5C: as shown in FIG. 2D, the switching module 40 is switched to the second switching state, the first switch 33 forms a path, and the second switch 34 forms an open circuit, so that the impedance sensing module 30 forms a third Configuration 52 and generating a third signal period;

S5D: as shown in FIG. 2E, the switching module 40 is switched to the first switching state, and the first switch 33 and the second switch 34 form an open circuit, so that the impedance sensing module 30 forms a fourth configuration. 53, and generate a fourth signal cycle;

S5E: analyzing the period of the first configuration 50, the second configuration 51, the third configuration 52, and the oscillation signal of the fourth configuration 53 to further combine the non-ideal conditions of the first operational amplifier circuit Considering, the result of matching the negative matching impedance 211 of the capacitor with the impedance of the capacitive stray element 131 is obtained.

S6: Adjust the value of the negative impedance matching impedance 211 according to the sensing result of the impedance sensing module 30, and compensate the impedance of the capacitive stray component 131 to output a linear triangular wave signal.

In summary, the present invention has the following features:

1. By setting the negative matching impedance, the impedance of the stray element can be compensated to output a linear triangular wave signal.

Second, the sensing impedance module is used to sense the negative matching impedance, and further adjustment is made to make the negative matching impedance and the impedance of the stray component more closely match, and the output is closer to the ideal linear triangular wave signal.

Therefore, the present invention is highly progressive and conforms to the requirements of the invention patent application, and the application is made according to law, and the praying office grants the patent as soon as possible.

The present invention has been described in detail above, but the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the scope of the invention. That is, the equivalent changes and modifications made by the scope of the present application should remain within the scope of the patent of the present invention.

10‧‧‧Linear triangular wave generation module
11‧‧‧First current source
12‧‧‧Solid capacitance
13‧‧‧ Stray components
131‧‧‧Capacitor stray components
132‧‧‧First current source stray components
14‧‧‧clock switching unit
15‧‧‧Window type comparison unit
20‧‧‧Negative impedance conversion module
21‧‧‧Negative matching impedance
211‧‧‧Capacitor negative matching impedance
212‧‧‧First current source negative matching impedance
22‧‧‧First operational amplification unit
221‧‧‧First reverse input
222‧‧‧First non-inverting input
223‧‧‧first output
23‧‧‧First resistance
24‧‧‧second resistance
30‧‧‧ Impedance Sensing Module
31‧‧‧Second operational amplification unit
311‧‧‧second reverse input
312‧‧‧Second non-inverting input
313‧‧‧second output
32‧‧‧Inverting unit
33‧‧‧First switch
34‧‧‧second switch
35‧‧‧first capacitor
36‧‧‧second capacitor
37‧‧‧second current source
40‧‧‧Switch Module
50‧‧‧First configuration
51‧‧‧Second configuration
52‧‧‧ Third configuration
53‧‧‧fourth configuration

Figure 1 is a schematic diagram of the circuit of the present invention. 2A is a schematic diagram of a sensing configuration switching manner of the impedance sensing module of the present invention. 2B is a schematic diagram of a first configuration circuit of the impedance sensing module of the present invention. 2C is a schematic diagram of a second configuration circuit of the impedance sensing module of the present invention. 2D is a schematic diagram of a third configuration circuit of the impedance sensing module of the present invention. 2E is a schematic diagram of a fourth configuration circuit of the impedance sensing module of the present invention. Figure 3 is a flow chart of the method of operation of the present invention.

10‧‧‧Linear triangular wave generation module

11‧‧‧First current source

12‧‧‧Solid capacitance

13‧‧‧ Stray components

131‧‧‧Capacitor stray components

132‧‧‧First current source stray components

14‧‧‧clock switching unit

15‧‧‧Window type comparison unit

20‧‧‧Negative impedance conversion module

21‧‧‧Negative matching impedance

211‧‧‧Capacitor negative matching impedance

212‧‧‧First current source negative matching impedance

22‧‧‧First operational amplification unit

221‧‧‧First reverse input

222‧‧‧First non-inverting input

223‧‧‧first output

23‧‧‧First resistance

24‧‧‧second resistance

30‧‧‧ Impedance Sensing Module

31‧‧‧Second operational amplification unit

311‧‧‧second reverse input

312‧‧‧Second non-inverting input

313‧‧‧second output

32‧‧‧Inverting unit

33‧‧‧First switch

34‧‧‧second switch

35‧‧‧first capacitor

36‧‧‧second capacitor

37‧‧‧second current source

40‧‧‧Switch Module

Claims (10)

A linear triangular wave generator with spurious effect compensation, comprising: a linear triangular wave generating module, comprising a first current source and a solid capacitor and a stray component electrically connected to the first current source, the stray component And generating, by the first current source, a stray effect of the solid capacitor, the first current source charges and discharges the solid capacitor to generate a linear triangular wave signal; and a negative connection electrically connected to the linear triangular wave generating module The impedance conversion module includes a negative matching impedance for compensating the impedance of the stray element; an impedance sensing module for sensing a degree of matching between the negative matching impedance and the impedance of the stray element; and an electrical property The switching module connected to the negative impedance conversion module and the impedance sensing module includes a first switching state and a second switching state for switching the sensing configuration of the impedance sensing module. The impedance sensing module senses the degree to which the negative matching impedance matches the impedance of the stray element. A linear triangular wave generator with spurious effect compensation as described in claim 1, wherein the stray element comprises a capacitive stray element and a first current source stray element. The linear triangular wave generator with spurious effect compensation according to claim 2, wherein the linear triangular wave generating module further comprises a clock switching unit electrically connected to the first current source and the solid capacitor, and a window type comparison unit electrically connected to the first current source and connected in parallel to the solid capacitor, wherein the clock switching unit controls the first current source to charge and discharge the solid capacitor, and the window type comparison unit is electrically connected to The physical capacitor controls the upper and lower limits of the output of the linear triangular wave signal. The linear triangular wave generator with spurious effect compensation as described in claim 3, wherein the negative impedance conversion module further includes a first operational amplification unit, a first resistor, and a second resistor, the first The operational amplifying unit includes a first inverting input, a first non-inverting input, and a first output. The first non-inverting input is electrically connected to the first current source and is connected in parallel with the physical capacitor. The first output end is electrically connected to the switching module, and the two ends of the first resistor are electrically connected to the first inverting input end and the switching module respectively, and the two ends of the second resistor are electrically connected The two ends of the negative matching impedance are electrically connected to the first non-inverting input terminal and the switching module respectively. The linear triangular wave generator with spurious effect compensation according to claim 4, wherein the impedance sensing module comprises a second operational amplification unit, an inverting unit, a first switch, and a second switch. a first capacitor, a second capacitor, and a second current source, the second operational amplifier unit includes a second inverting input, a second non-inverting input, and a second output, the second The non-inverting input is electrically connected to the switching module, and the two ends of the first switch are electrically connected to the second output end and the first capacitor, and the first capacitor is electrically away from the one end of the first switch Connected to the first non-inverting input terminal, the two ends of the second switch are electrically connected to the negative matching impedance and the second output end, and the two ends of the second capacitor are electrically connected to the switching module and The first non-inverting input terminal is electrically connected to the second output end and the second current source; when the switching module is switched to the first switching state, the first operational amplifying unit is enabled The first output and the second operational amplifier The second non-inverting input end of the unit is electrically connected to the second capacitor; when the switching module is switched to the second switching state, the first output end of the first operational amplifying unit and the second operational amplifier are amplified The second non-inverting input of the single is electrically connected to the first resistor and the negative matching impedance. The linear triangular wave generator with spurious effect compensation according to claim 5, wherein the impedance sensing module performs impedance sensing through four sensing configurations, so that the switching module is switched to the first a switching state, the first switch is connected, and the second switch is not connected, forming a first configuration; switching the switching module to the first switching state, the first switch is not connected, and the second switch is connected Forming a second configuration; when the switching module is switched to the second switching state, the first switch is connected, and the second switch is not connected, forming a third configuration; switching the switching module to the When the first switching state, the first switch, and the second switch are not connected, forming a fourth configuration; and the four configuration switches are used to consider the non-ideal conditions of the first operational amplifying unit together to obtain the The result of the matching of the negative matching impedance to the impedance of the stray element. A method for compensating the spurious effect of a linear triangular wave generator, comprising the following steps: S1: charging and discharging a physical capacitor by using a first current source in a linear triangular wave generating module to generate a triangular wave signal, and the The linear triangular wave generating module has a stray component generated by a spurious effect; S2: designing a negative matching impedance matched with the stray component in a negative impedance conversion module; S3: converting the negative impedance The module is electrically connected to the first current source and connected in parallel to the solid capacitor, and the impedance of the stray component is compensated by the negative matching impedance; S4: sensing the negative matching impedance by using an impedance sensing module The matching degree of the impedance of the stray component; S5: electrically connecting a switching module to the negative impedance conversion module and the impedance sensing module, including a switch mode for switching the impedance sensing module a first switching state and a second switching state, wherein the impedance sensing module performs sensing of the matching degree of the negative matching impedance with the impedance of the stray component; and S6: according to the impedance sensing module Sensing results to adjust the value of the negative impedance matching, the output linear triangular wave signal. The method for compensating for the spurious effect of the linear triangular wave generator according to claim 7, wherein the S1 step further comprises the following steps: S1A: controlling the physical capacitor by using the first clock source to control the first current source Discharging, generating the triangular wave signal; and S1B: controlling the upper and lower limits of the triangular wave signal by a window type comparing unit. The method for compensating for the spurious effect of the linear triangular wave generator according to claim 7 , wherein the impedance conversion module further comprises a first operational amplification unit, a first resistor and a second resistor, the first The operational amplifying unit includes a first inverting input, a first non-inverting input, and a first output. The first non-inverting input is electrically connected to the first current source and is connected in parallel with the physical capacitor. The first output end is electrically connected to the switching module, and the two ends of the first resistor are electrically connected to the first inverting input end and the switching module, and the second resistor is electrically connected to the first An inverting input end, the two ends of the negative matching impedance are electrically connected to the first non-inverting input end and the switching module respectively; the impedance sensing module comprises a second operational amplifying unit and an inverting a unit, a first switch, a second switch, a first capacitor, a second capacitor, and a second current source, the second operational amplifier unit includes a second inverting input and a second non-inverting input End and a second output The second non-inverting input is electrically connected to the switching module, and the two ends of the first switch are electrically connected to the second output end and the first capacitor, and the first capacitor is away from the first switch One end is electrically connected to the first non-inverting input end, and the two ends of the second switch are electrically connected to the negative matching impedance and the second output end, and the two ends of the second capacitor are electrically connected to the a switching module and the first non-inverting input terminal, the inverting unit is electrically connected to the second output end and the second current source; when the switching module is switched to the first switching state, the first a first output end of an operational amplifying unit and a second non-inverting input end of the second operational amplifying unit are electrically connected to the second capacitor; when the switching module is switched to the second switching state, The first output end of the first operational amplifying unit and the second non-inverting input end of the second operational amplifying unit are electrically connected to the first resistor and the negative matching impedance. The method for compensating the spurious effect of the linear triangular wave generator according to claim 9 , wherein the step S5 further comprises the following steps: S5A: switching the switching module to the first switching state, the first switch Forming a path, the second switch forms an open circuit, the impedance sensing module forms a first configuration, and generates a first signal period; S5B: switching the switching module to the first switching state, the first The switch forms an open circuit, and the second switch forms a path, so that the impedance sensing module forms a second configuration and generates a second signal period; S5C: switching the switching module to the second switching state, the first a switch forming a path, the second switch forming an open circuit, the impedance sensing module forming a third configuration, and generating a third signal period; S5D: switching the switching module to the first switching state, the The first switch forms an open circuit with the second switch, the impedance sensing module forms a fourth configuration, and generates a fourth signal period; and S5E: analyzes the first configuration, the second configuration, and the The third configuration and the fourth configuration Oscillation signal period, and thus the non-ideal conditions of the first operational amplifier Taken together, the results obtained by the matching impedance to the negative impedance of the matching degree of a stray element.