Noise analysis device, noise analysis method, and program

Abstract

A time range setting unit (14) acquires a plurality of occurrence times (ton (i), off (i)) at which each of a plurality of times of opening and closing of a semiconductor element occurs. Phase conversion units (14a, 14b) generate a plurality of pieces of phase difference information for performing a phase conversion reflecting a time difference of a plurality of occurrence times on a noise spectrum when a semiconductor element is opened and closed. The addition unit (18) adds a plurality of noise spectra (NSon (i), NSoff (i)) obtained by phase-converting the noise spectra (SPNon, SPNoff) during opening and closing of the semiconductor element using the plurality of pieces of phase difference information, thereby calculating a calculation result (RTNS) of a total spectrum generated by opening and closing of the semiconductor element.

Description

Technical Field

[0001] The present disclosure relates to a noise analysis device, a noise analysis method, and a program. Background Art

[0002] In order to predict electromagnetic noise generated by switching of semiconductor elements of electronic equipment or power converters, there is known a technique for simulating and deriving noise at a noise observation point using an information processing device (hereinafter referred to as “noise analysis technique”).

[0003] For example, a noise analysis technique is known that performs circuit simulation in which a noise propagation path is modeled by a combination of circuit elements such as resistors, inductors, and capacitors. On the other hand, when modeling is difficult by a combination of circuit elements, noise analysis using a noise transfer function obtained by electromagnetic field analysis is known to be effective.

[0004] For example, Japanese Patent Application Publication No. 2013-242649 (Patent Document 1) discloses the following noise analysis technology: a semiconductor element to be switched on and off is used as a noise source, and a transient waveform (e.g., a voltage waveform) including both the semiconductor element being turned on and turned off is Fourier transformed in advance to calculate a frequency spectrum of the noise source (hereinafter referred to as "noise source spectrum").

[0005] Furthermore, according to the noise analysis technique of Patent Document 1, after calculating the noise source spectrum, the noise transfer function from the noise source to the noise observation point is multiplied by the noise source spectrum, thereby being able to derive the noise at the noise observation point with high accuracy in consideration of the complex propagation characteristics of the noise.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2013-242649 Summary of the invention

[0009] Technical issues to be solved by the invention

[0010] In a relatively simple switching control DCDC converter, the length of the on period and the length of the off period of the semiconductor element are often considered to be constant in a stable operating state. In this case, noise analysis can be achieved by treating the transient waveform of one switching cycle as a noise source, wherein the transient waveform of one switching cycle includes one transient waveform when turned on and one transient waveform when turned off, respectively, corresponding to the length of the on period and the length of the off period of the semiconductor element in the stable operating state.

[0011] The higher the noise analysis accuracy in the high frequency domain, the shorter the time step of the transient waveform needs to be, usually set to several [ns]. In contrast, the on-period length and off-period length of a semiconductor element need to be several tens of [μs], which is longer than the above time step.

[0012] Therefore, when a transient waveform of one switching cycle, that is, one on and one off, is used as noise source data, the number of time steps also increases. In addition, when transient waveforms of multiple switching cycles are used as noise source data, there is a concern that the Fourier transform will take a long time due to the increase in the number of time steps that are the objects of the Fourier transform.

[0013] As described above, if the DCDC converter is relatively simple, it is possible to perform noise analysis with a suppressed time width as a target of Fourier transform using a noise source spectrum obtained by Fourier transforming a transient waveform of one switching cycle.

[0014] However, in recent years, the on-off control of power conversion circuits has been continuously improved, and even in a stable working state, the length of the on period and the length of the off period sometimes change. In particular, it is known that in PWM (Pulse Width Modulation) inverters, in principle, semiconductor elements are controlled to be on and off as the length of the on period and the length of the off period change. When such a power converter is used as the object of noise analysis, when the transient waveforms containing one on and one off as described above are analyzed as noise sources, the behavior of the phase of the noise changing due to the change of the on period length and the off period length can no longer be reflected in the noise source. As a result, there is a concern that the accuracy of noise analysis will be reduced.

[0015] In order to reflect the behavior of the change in the length of the on-period and the length of the off-period in the noise source, there is an option to perform noise analysis using noise source data obtained by Fourier transforming transient waveforms including multiple on-and-off cycles. On the other hand, since the time width of the object of Fourier transform increases in order to obtain such noise source data, the time required for Fourier transform becomes longer. As a result, the time for noise analysis becomes longer, which becomes a technical issue.

[0016] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a noise analysis technique capable of deriving a calculation result of observation noise quickly and accurately even when the on-period length and the off-period length of a semiconductor element vary.

[0017] Technical solutions for solving technical problems

[0018] According to one aspect of the present disclosure, a noise analysis device is provided. The noise analysis device calculates a total spectrum of noise generated by switching on and off as at least one of the switching on and off of a semiconductor element. The noise analysis device includes a first acquisition unit, a phase conversion unit, and a first addition unit. The first acquisition unit acquires information indicating a plurality of occurrence times of multiple switchings occurring during a noise analysis target period including multiple switchings of the semiconductor element. The phase conversion unit generates a plurality of phase difference information corresponding to the plurality of occurrence times acquired by the first acquisition unit, respectively, and the plurality of phase difference information is used to perform a phase conversion reflecting the time difference of the plurality of switchings on and off on the noise spectrum of the semiconductor element when it is switched on and off. The first addition unit calculates a total spectrum obtained by adding a plurality of noise spectra, and the plurality of noise spectra are obtained by phase-converting the noise spectrum of the semiconductor element when it is switched on and off using a plurality of phase difference information.

[0019] According to another aspect of the present disclosure, a noise analysis method is provided. The noise analysis method calculates a total spectrum of noise generated by at least one of the switching on and off of a semiconductor element. In the noise analysis method, (1) information representing multiple occurrence times of multiple switchings occurring during a noise analysis object period including multiple switchings of the semiconductor element is obtained, (2) multiple phase difference information corresponding to the multiple occurrence times is generated, and the multiple phase difference information is used to perform a phase transformation reflecting the time difference of the multiple switchings on the noise spectrum of the semiconductor element when it is switched on and off, and (3) a total spectrum obtained by adding the multiple noise spectra is calculated, and the multiple noise spectra are obtained by phase transforming the noise spectrum of the semiconductor element when it is switched on and off using the multiple phase difference information.

[0020] Effects of the Invention

[0021] According to the present disclosure, it is possible to provide a noise analysis technique capable of deriving a calculation result of observation noise at high speed and accurately even when the on-period length and the off-period length of a semiconductor element vary. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a conceptual diagram for explaining an example of the hardware configuration of the noise analysis device according to the present embodiment.

[0023] Figure 2 This is a block diagram for explaining a configuration example of a noise analysis device according to the first embodiment.

[0024] Figure 3 This is a circuit diagram illustrating an example of a noise analysis target.

[0025] Figure 4 This is a waveform diagram showing an example of a turn-on transient waveform (voltage waveform).

[0026] Figure 5This is a waveform diagram showing an example of a turn-off transient waveform (voltage waveform).

[0027] Figure 6 This is a waveform diagram showing another example of the turn-off transient waveform (current waveform).

[0028] Figure 7 To show Figure 2 The waveform diagram of an example of the opening and closing control signal shown.

[0029] Figure 8 3 is a waveform diagram showing a turn-on transient waveform (voltage waveform) after broken line approximation.

[0030] Fig. 9 To show Figure 8 A characteristic diagram of an example of a noise source spectrum obtained by Fourier transforming the conduction waveform of .

[0031] Fig.10 For illustration Figure 2 A block diagram of a configuration example of an observation noise calculation unit shown in FIG.

[0032] Fig.11 For illustration Fig.10 A block diagram of an example configuration of a total calculation unit shown in FIG.

[0033] Fig.12 This is a block diagram for explaining a configuration example of an observation noise calculation unit for calculating observation noise from a plurality of noise sources.

[0034] Fig.13 For illustration Figure 2 2 is a block diagram of a modified example of the structure of the observation noise calculation unit shown in FIG.

[0035] Fig.14 This is a block diagram for explaining a modified example of the noise analysis function unit.

[0036] Fig.15 This is a block diagram for explaining a first configuration example of a timing deviation correction process for a transient waveform.

[0037] Fig.16 This is a block diagram for explaining a second configuration example of the timing deviation correction processing of the transient waveform.

[0038] Fig.17 This is the first example of a wiring diagram for a noise transfer function.

[0039] Fig.18 This is the second example of the wiring diagram of the noise transfer function.

[0040] Fig.19 This is the third example of the wiring diagram of the noise transfer function.

[0041] Fig. 20This is the fourth example of the wiring diagram for the noise transfer function.

[0042] Fig.21 A block diagram illustrating an example of a structure for integrating a noise transfer function.

[0043] Fig. 22 This is a circuit diagram for explaining another example of a noise analysis target.

[0044] Fig.23 This is a circuit diagram for explaining another example of a noise analysis target.

[0045] Fig.24 To show Fig.23 Spectrum diagram of an example of the observed noise calculation results of the noise analysis target circuit shown.

[0046] Fig.25 for Fig.24 A zoomed-in view of part of the frequency domain.

[0047] Fig.26 This is a block diagram for explaining a configuration example of a noise analysis device according to the second embodiment.

[0048] Fig. 27 For illustration Fig.26 A block diagram of a structural example of the on / off separation unit in FIG.

[0049] Fig.28 This is a block diagram for explaining a configuration example of a noise analysis device according to a third embodiment.

[0050] Fig.29 This is a block diagram for explaining a function added to the observation noise calculation unit 10 in the noise analysis of the third embodiment.

[0051] Fig.30 This is a spectrum diagram showing an example of the observation noise calculation result obtained by the noise analysis according to the third embodiment.

[0052] Fig.31 This is a block diagram for explaining a configuration example of a noise analysis device according to a fourth embodiment.

[0053] Fig.32 This is a block diagram for explaining the function added to the observation noise calculation unit in the noise analysis of the fourth embodiment.

[0054] Fig.33 For illustration Figure 1 A block diagram of an example of the hardware configuration of an information processing device shown in FIG.

[0055] Fig.34 A block diagram illustrating a variation of performing phase transformation in the time domain.

[0056] Fig.35The present invention is a block diagram for explaining a first configuration example of a noise analysis device for calculating observation noise using a noise source as a noise observation point.

[0057] Fig.36 For illustration Fig.35 2 is a block diagram of a first configuration example of an observation noise calculation unit shown in FIG.

[0058] Fig.37 For illustration Fig.36 A block diagram of the structure of the total calculation unit shown.

[0059] Fig.38 For illustration Fig.35 2 is a block diagram of a second configuration example of the observation noise calculation unit shown in FIG.

[0060] Fig.39 This is a block diagram for explaining a second configuration example of a noise analysis device for calculating observation noise using a noise source as a noise observation point.

[0061] Fig.40 This is a block diagram for explaining a third configuration example of a noise analysis device for calculating observation noise using a noise source as a noise observation point.

[0062] Fig.41 This is a block diagram for explaining a fourth configuration example of a noise analysis device for calculating observation noise using a noise source as a noise observation point.

[0063] Fig.42 This is a block diagram for explaining a fifth configuration example of a noise analysis device for calculating observation noise using a noise source as a noise observation point. Reference numerals

[0064] 1, 1Y: noise analysis function unit; 3: switch control signal acquisition unit; 4: noise transfer function acquisition unit; 4X: transfer function integration unit; 5: measuring device parameter acquisition unit; 6: load current waveform acquisition unit; 10, 11: observation noise calculation unit; 10X, 10Y, 10Y', 10Z: total calculation unit; 12, 12Y, 13, 15, 16, 43, 44: multiplication unit; 14: time range setting unit; 14a~14d: phase conversion unit; 17, 18, 19: addition unit; 20: transient waveform acquisition unit; 21: on transient waveform acquisition unit; 22: off transient waveform acquisition unit; 23, 24: Fourier transform unit; 25: on noise source spectrum acquisition unit; 26: off Noise source spectrum acquisition unit; 27a, 27b: time deviation detection function unit; 28a, 28b: time deviation correction function unit; 29: on / off separation unit; 31: on time detection unit; 32: off time detection unit; 33: on transient waveform output unit; 34: off transient waveform output unit; 40: weighted operation function unit; 41: window function calculation unit; 42: weighting coefficient setting unit; 51, 53: information processing device; 52: information display device; 54: cloud; 60: noise source spectrum correction unit; 61, 62: load current value acquisition unit; 65, 66: interpolation calculation function unit; 71: first noise source; 72: second noise source; 73: first noise observation point; 7 4: 2nd noise observation point; Gcmn, Goff, Gon: noise transfer function; 81: noise transfer function; 81a: 1st noise transfer function; 81b: 2nd noise transfer function; 82~84: relay point; 101, 102: semiconductor element (noise source); 200: analysis object circuit; 201: input positive terminal; 202: input negative terminal; 203, 303: load; 204: capacitor; 205, 411, 412, 413: intermediate terminal; 220: CPU; 230: memory; 240: I / O circuit; 250: bus; 301: output positive terminal; 302: output negative terminal; 304: reactor; 401: 1st branch ( arm); 402: the second branch; 403: the third branch; 405: AC load; NS(i): observed noise; NSoff(i): disconnected observed noise; NSon(i): connected observed noise; Prt1~Prt4: ports; RTNS: observed noise calculation results; SPNoff: disconnected noise source spectrum; SPNon: connected noise source spectrum; Tstr: start time; Tend: end time; Vdi: diode voltage; Vtr: transistor voltage; WGoff(i), WGon(i): weighting coefficients; X1~XJ, X(i): load current value; toff(i): disconnection time; ton(i): connection time; w(t): window function. DETAILED DESCRIPTION

[0065] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In addition, the same reference numerals are attached to the same or corresponding parts in the drawings below, and their description will not be repeated in principle. Implementation method 1.

[0066] First, use Figure 1 and Figure 2 A configuration example of a noise analysis device according to the present embodiment will be described. Figure 1 An example of the hardware configuration of a noise analysis device is shown. Figure 2 A block diagram illustrating a configuration example of the noise analysis device according to the first embodiment is shown.

[0067] Reference Figure 1 The function of the noise analysis device of this embodiment is realized, for example, by the information processing device 51 executing a predetermined noise analysis program. That is, when the noise analysis program is executed, the information processing device 51 performs the calculation processing to realize Figure 2 The functions of the blocks included in the noise analysis function unit 1 are used to form the noise analysis device of the present embodiment, or to execute the noise analysis method. This makes it possible to perform simulation of observation noise to which the noise analysis technique of the present embodiment is applied.

[0068] That is, the functions of each block described in the block diagram shown below are basically realized by software processing based on the execution of the program. However, at least a part of the functions of any block can also be constructed by a digital circuit or analog circuit such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit).

[0069] Fig.33 A hardware configuration example of the information processing device 51 is shown.

[0070] For example Fig.33 As shown, the information processing device 51 is configured based on a computer and includes a CPU (Central Processing Unit) 220, a memory 230, and an input / output (I / O) circuit 240. The CPU 220, the memory 230, and the I / O circuit 240 can mutually transmit and receive data via a bus 250.

[0071] A program including a noise analysis program is stored in advance in a part of the memory 230, and the noise analysis described below can be performed by executing the program by the CPU 220. The I / O circuit 240 communicates with other devices such as the I / O circuit 240 via a communication device (not shown). Figure 1The information display device 52, the information processing device 53 and the cloud 54 shown in the figure input and output signals and data.

[0072] The observed noise calculation result obtained as a result of the simulation in the information processing device 51 can be displayed on the information display device 52. Figure 1 The information processing device 51 and the information display device 52 are separate bodies, but the two may be integrated.

[0073] In addition, in addition to being displayed on the information display device 52, the observed noise calculation result can also be stored in the information processing device 51. In addition, the storage location of the observed noise calculation result is not limited to the information processing device 51 that performs the simulation, but can also be other information processing devices 53 connected to the information processing device 51 via a wired or wireless network, or can also be the cloud 54.

[0074] Next, refer to Figure 2 The noise analysis function unit 1 includes a switching control signal acquisition unit 3 , a noise transfer function acquisition unit 4 , a connection transient waveform acquisition unit 21 , and a disconnection transient waveform acquisition unit 22 .

[0075] The ON transient waveform acquisition unit 21 acquires an ON transient waveform (voltage waveform) on the time axis of a semiconductor element (noise source) being switched on and off. Similarly, the OFF transient waveform acquisition unit 22 acquires an OFF transient waveform (voltage waveform) on the time axis of the semiconductor element.

[0076] Here, Figure 3 An example of a circuit diagram for noise analysis is shown below. Figure 3 In order to simplify the diagram, the description of cables, power supplies and peripheral circuits is omitted.

[0077] Reference Figure 3 The analysis target circuit 200 includes an upper arm semiconductor element 101 and a lower arm semiconductor element 102 connected in series between an input positive terminal 201 and an input negative terminal 202. A smoothing capacitor 204 is connected between the input positive terminal 201 and the input negative terminal 202.

[0078] The high potential side terminal of the upper branch semiconductor element 101 is connected to the input positive terminal 201, and the low potential side terminal of the lower branch semiconductor element 102 is connected to the input negative terminal 202. The low potential side terminal of the upper branch semiconductor element 101 and the high potential side terminal of the lower branch semiconductor element 102 are connected to the intermediate terminal 205. The load 203 is connected between the input positive terminal 201 and the intermediate terminal 205. Figure 3 In the structural example, the upper arm semiconductor element 101 mainly operates as a diode, and the lower arm semiconductor element 102 mainly operates as a transistor.

[0079] Or, in Figure 3 In the structure, the load 203 may be connected between the negative input terminal 202 and the intermediate terminal 205. In this case, in the analysis target circuit 200, the upper arm semiconductor element 101 mainly operates as a transistor, and the lower arm semiconductor element 102 mainly operates as a diode.

[0080] In addition, the circuit to be analyzed 200 may be configured as a set (branch) of a plurality of branches connected in parallel between the input positive terminal 201 and the input negative terminal 202, wherein the set is a set of upper branch semiconductor elements and lower branch semiconductor elements connected in series. In addition, in each branch, the number of semiconductor elements connected in series is not limited to two, but may be any number.

[0081] In the analysis object circuit 200, the upper arm semiconductor element 101 and the lower arm semiconductor element 102 (hereinafter also simply collectively referred to as "semiconductor element") are each switched on and off so that a desired power conversion is performed between the DC power input between the positive terminal 201 and the negative terminal 202 and the power (DC power or AC power) input and output to the load 203. By the switching control, the semiconductor element is repeatedly switched on from the off state to the on state and switched off from the on state to the off state.

[0082] Figure 4~Figure 6 Examples of a turn-on transient waveform and a turn-off transient waveform are shown. Figure 4 and Figure 5 The voltage waveform is shown as a transient waveform.

[0083] Figure 4 The waveforms of the inter-terminal voltage Vtr (hereinafter also referred to as transistor voltage Vtr) of the semiconductor element (working as a transistor) and the inter-terminal voltage Vdi (hereinafter also referred to as diode voltage Vdi) of the semiconductor element (working as a diode) when the semiconductor element (working as a transistor) is turned on at t1 are shown. During the cut-off period of the semiconductor element (working as a transistor), Vdi is near zero due to the conduction of the diode, while Vtr>0 prevents the conduction of the transistor. In response to the turn-on of the transistor, Vtr decreases to 0, while Vdi rises due to the turn-off of the diode. The sudden voltage changes in Vtr and Vdi at this time may become a noise source. That is, the voltage waveform after t1 is equivalent to the turn-on transient waveform.

[0084] In addition, t1 is the reference time in the turn-on transient waveform, and is defined as t1 = 0. Figure 4In the embodiment, t1 is determined to correspond to the time when the voltage change of Vtr and Vdi starts, but t1 as a reference may be determined to correspond to the time when the gate voltage of the semiconductor element starts to change. Alternatively, t1 may be determined to correspond to the time when the switching control signal described later starts to change.

[0085] Likewise, Figure 5 The voltage Vtr between the terminals of the semiconductor element (working as a transistor) and the voltage Vdi between the terminals of the semiconductor element (working as a diode) when the semiconductor element (working as a transistor) is turned off at t2 are shown. During the conduction period of the transistor, Vtr is near zero, while Vdi>0 prevents the conduction of the diode. In response to the disconnection of the transistor, Vtr starts to rise from 0, while Vdi decreases to 0 due to the conduction of the diode. At this time, the voltage sudden change of Vtr and Vdi may become a noise source. That is, the voltage waveform after t2 is equivalent to the disconnection transient waveform.

[0086] In addition, t2 is the reference time in the disconnection transient waveform, which is defined as t2 = 0. Figure 5 In the embodiment, t2 is determined to correspond to the time when the voltage change of Vtr and Vdi starts, but t2 as a reference may be determined to correspond to the time when the gate voltage of the semiconductor element starts to change. Alternatively, t2 may be determined to correspond to the time when the switching control signal described later starts to change.

[0087] Whenever a semiconductor element is turned on and off, Figure 4 and Figure 5 Since the voltage changes shown are known, the turn-on transient waveform and turn-off transient waveform of the semiconductor element can be obtained in advance based on the simulation results or the actual measurement data.

[0088] For example, an oscilloscope (not shown) with a trigger function and a memory function can be used to acquire measured data. Specifically, the measured data is stored by using the on or off of the semiconductor element as a trigger. Figure 4 or Figure 5 The measured waveform shown can obtain the turn-on transient waveform and the turn-off transient waveform.

[0089] Or you can Figure 6 As shown, the current waveform (such as transistor current Itr) is taken as a transient waveform. As an example, Figure 6 Show Figure 3An example of a current measured waveform of the lower arm semiconductor element 102 (mainly operating as a transistor) in the analysis target circuit 200. Regarding the current waveform, the transient waveform can also be predetermined based on the simulation result or the measured data (oscilloscope). As described above, the ON transient waveform and the OFF transient waveform acquired by the ON transient waveform acquisition unit 21 and the OFF transient waveform acquisition unit 22 do not necessarily have to be voltage waveforms, and current waveforms can be used as either or both.

[0090] In addition, regarding the turn-on transient waveform and turn-off transient waveform of the semiconductor element obtained by actual measurement or simulation, a database of the transient waveform can be pre-stored in any device among the information processing devices 51 , 53 and the cloud 54 . Figure 2 The shown turning-on transient waveform acquisition unit 21 and turning-off transient waveform acquisition unit 22 can acquire the turning-on transient waveform and the turning-off transient waveform by accessing the database.

[0091] Thus, the closing transient waveform acquisition unit 21 acquires information indicating a voltage change or a current change on the time axis when the power is turned on once. Similarly, the opening transient waveform acquisition unit 22 acquires information indicating a voltage change or a current change on the time axis when the power is turned off once.

[0092] In addition, in Figure 3 In the circuit composed of transistors and diodes shown in the example, Figure 4 and Figure 5 As shown in Figure 1, when the transistor is turned on, the diode is off, and when the transistor is turned off, the diode is on. Therefore, strictly speaking, the turn-on transient waveform of the semiconductor element ( Figure 4 ) includes the turn-on transient waveform of Vtr and the turn-off transient waveform of Vdi. Similarly, strictly speaking, the turn-off transient waveform of the semiconductor element ( Figure 5 ) includes the turn-off transient waveform of Vtr and the turn-on transient waveform of Vdi.

[0093] In addition, when the noise of only one of the transistor and the diode is dominant, only one of the transient voltage waveform or transient current waveform of the transistor and the transient voltage waveform or transient current waveform of the diode may be used as the on-transient waveform and the off-transient waveform.

[0094] In addition, Figure 3 The analysis target circuit 200 shown in FIG. 1 has two semiconductor elements as noise sources, but Figure 2 In order to simplify the description, a configuration for analyzing the noise output from one noise source (semiconductor element) is shown.

[0095] Refer again Figure 2The switch control signal acquisition unit 3 acquires the switch control signal including the information of the turn-on time and the turn-off time of the semiconductor element. The switch control signal includes the time series information of the turn-on and turn-off of the semiconductor element as the noise source.

[0096] For example, being able to use Figure 7 The gate signal for specifying the on-period and off-period of the semiconductor element is shown as the opening and closing control signal.

[0097] Reference Figure 7 The gate signal is time domain data that is set to "1" during the period when the semiconductor element should be controlled to be in the on state, and is set to "0" during the period when the semiconductor element should be controlled to be in the off state. In this case, the moment when the value of the gate signal as the switching control signal changes from "0" to "1" corresponds to the turn-on occurrence moment, and the moment when the value of the gate signal changes from "1" to "0" corresponds to the turn-off occurrence moment.

[0098] In addition, the value of the switching control signal is not limited to the digital value "0" and "1", and may be an analog value set to be different between the on state and the off state. In this case, the time when the magnitude relationship between the analog value and the predetermined threshold value is reversed corresponds to the on time or the off time.

[0099] In this way, one switching control signal is prepared for one noise source (semiconductor element), and each switching control signal includes information on the time axis indicating the time when the corresponding semiconductor element (noise source) turns on and turns off. In addition, it is also possible to define that the time when the semiconductor element (working as a transistor) turns on is the time when the semiconductor element (working as a diode) turns off, and the time when the semiconductor element (working as a transistor) turns off is the time when the semiconductor element (working as a diode) turns on, and only the switching control signal of the semiconductor element (working as a transistor) is prepared.

[0100] Specifically, the switching control signal includes information on the time axis indicating multiple on-times and multiple off-times for one semiconductor element (noise source). In addition, the switching control signal may also be composed of information indicating the on-times and off-times themselves.

[0101] By including a plurality of on-times and off-times in this manner, changes in the on-period length and the off-period length of the semiconductor element can be reflected in the switching control signal data.

[0102] Refer again Figure 2The noise analysis function unit 1 further includes Fourier transform units 23 and 24 and an observed noise calculation unit 10. The Fourier transform unit 23 outputs a frequency domain on-noise source spectrum SPNon obtained by Fourier transforming the on-transient waveform acquired by the on-transient waveform acquisition unit 21. Similarly, the Fourier transform unit 24 outputs a frequency domain off-noise source spectrum SPNoff obtained by Fourier transforming the off-transient waveform acquired by the off-transient waveform acquisition unit 22. The on-noise source spectrum SPNon and the off-noise source spectrum SPNoff obtained by Fourier transforming the transient waveform data on the time axis by the Fourier transform units 23 and 24 are input to the observed noise calculation unit 10 together with the on-off control signal from the on-off control signal acquisition unit 3 and the noise transfer function from the noise transfer function acquisition unit 4.

[0103] Here, use Figure 8 and Fig. 9 An example of Fourier transform processing of a transient waveform will be described.

[0104] Figure 8 Show Figure 4 The example of the broken line approximation of the semiconductor device's turn-on transient waveform (transistor voltage Vtr) is shown in FIG. When using the actual measured waveform, it is preferable to use Figure 8 The measured waveform indicated by the solid line is approximated to the broken line as indicated by the dotted line, and the waveform approximated by the broken line is the object of Fourier transform.

[0105] The waveform after the broken line approximation may be generated by automatically performing the broken line approximation in the noise analysis function unit 1, or a waveform obtained by performing the broken line approximation on the on-transient waveform and the off-transient waveform acquired by the on-transient waveform acquisition unit 21 and the off-transient waveform acquisition unit 22 may be prepared in advance. In addition, the broken line approximation is not limited to the broken line approximation, and any regression curve may be used for approximation.

[0106] Fig. 9 Show Figure 8 The waveform after the broken line approximation shown is subjected to Fourier transform. Usually, in Fourier transform, calculation is performed to obtain a complex spectrum. Fig. 9 The absolute value of the spectrum at each frequency is plotted. The Fourier transform is obtained by, for example, the following equation (1).

[0107] [Mathematical formula 1]

[0108] …… (1)

[0109] In equation (1), N(f) is the noise source spectrum at frequency f. n(t) is the voltage value or current value representing the on-state transient waveform or off-state transient waveform on the time axis where t1 and t2 are defined as t=0. w(t) is the window function, and T is the time width of the window function.

[0110] Alternatively, in the Fourier transform units 23 and 24, a modified form or an approximate expression that can obtain a calculation result of the Fourier transform equivalent to the expression (1) can also be used. In addition, the time width T of the window function is set arbitrarily. When the time width T of the window function is longer than the time length of the data of the transient waveform, the data of the transient waveform can be interpolated by extrapolation. In addition, although it is not necessary to calculate the noise source spectrum of f = 0, that is, direct current, in the case of f = 0, it is necessary to divide the value obtained by the expression (1) by 2.

[0111] Fourier transform units 23 and 24 transform the transient waveforms ( Figure 4~Figure 6 That is, it is generally understood that the number of transient waveforms (on and off) as the object of Fourier transform in the Fourier transform units 23 and 24 is less than the number of multiple on occurrence times and multiple off occurrence times obtained from the switching control signal.

[0112] Refer again Figure 2 , although in Figure 2 In the example of FIG. 1 , the Fourier transform units 23 and 24 perform Fourier transform on the on-transient waveform and the off-transient waveform in parallel, but a common Fourier transform unit may perform Fourier transform on the on-transient waveform and the off-transient waveform sequentially.

[0113] The observed noise calculation unit 10 calculates the observed noise calculation result RTNS using the on-noise source spectrum SPNon and off-noise source spectrum SPNoff from the Fourier transform units 23 and 24 , the switching control signal data from the switching control signal acquisition unit 3 , and the noise transfer function from the noise transfer function acquisition unit 4 .

[0114] Fig.10 Show instructions Figure 2 1 is a block diagram of a configuration example of the observation noise calculation unit 10 shown in FIG.

[0115] Reference Fig.10 The observed noise calculation unit 10 includes multiplication units 12, 13 and a total calculation unit 10X. The noise transfer function acquisition unit 4 acquires the noise transfer function Gon when the switch is on and the noise transfer function Goff when the switch is off. Fig.10 In the example above, the noise transfer functions for on and off are set separately.

[0116] The multiplication unit 12 multiplies the on-noise source spectrum SPNon by the on-noise transfer function Gon. The multiplication unit 13 multiplies the off-noise source spectrum SPNoff by the off-noise transfer function Goff.

[0117] Here, the noise transfer function refers to data including a transfer function in the frequency domain from the noise source to the noise observation point, and can be obtained in advance by, for example, electromagnetic field analysis or circuit analysis. The noise transfer function is represented by, for example, the voltage or current at the noise observation point when a 1 [V] voltage or a 1 [A] current is applied to the noise source. In order to consider the phase difference between the noise source and the noise observation point, it is necessary to represent the voltage or current at the noise observation point as a complex number.

[0118] In addition, as described later, when there are a plurality of noise sources and noise observation points, the data of the noise transfer function includes the noise transfer function for each combination of the noise source and the noise observation point. The object observed at the noise observation point is not limited to voltage and current, but may be an electric field or a magnetic field, but in this specification, the case of electric field and magnetic field is omitted, and voltage and current are described as noise.

[0119] The data of the noise transfer function may be the data of the S parameters of the port having the noise source and the noise observation point, and the formula for the voltage or current at the noise observation point when a 1 [V] voltage or a 1 [A] current is applied to the noise source, which is derived by performing a transformation calculation of the S parameters, can be used as the noise transfer function obtained by the noise transfer function acquisition unit 4.

[0120] Furthermore, when using S parameters of a port having multiple noise sources and multiple noise observation points, the noise transfer function can be derived for each combination of the noise source and the noise observation point based on the data of one S parameter. When performing S parameter conversion, any impedance can be applied in series or in parallel to the noise source. For example, the resistance of the semiconductor element when it is turned on can be applied in series to a voltage of 1 [V], and the capacitance of the semiconductor element when it is turned off can be applied in parallel to a current of 1 [A].

[0121] Alternatively, the noise transfer function may be set using Y parameters, Z parameters, or F parameters that can be converted to and from S parameters instead of S parameters.

[0122] like Fig.10 As shown, the on-observation noise and the off-observation noise are calculated by multiplying the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff by the noise transfer function Gon when on and the noise transfer function Goff when off, respectively. In addition, the observation noise is calculated by adding up the on-observation noise and the off-observation noise based on the data of the opening and closing control signal.

[0123] Fig.11 Show instructions Fig.1010X is a block diagram showing an example of the configuration of a total calculation unit 10X.

[0124] Reference Fig.11 The total calculation unit 10X includes a time range setting unit 14 , phase conversion units 14 a and 14 b , multiplication units 15 and 16 , and addition units 17 and 18 .

[0125] The time range setting unit 14 extracts the 1st to Nth (N: natural number) connection occurrence times and disconnection occurrence times contained in the specified noise analysis target period (start time Tstr~end time Tend) from the switching control signal from the switching control signal acquisition unit 3. Thus, the i-th (i: 1~N) connection time ton(i) and the i-th (i: 1~N) disconnection time toff(i) are obtained from the switching control signal. In addition, the noise analysis target period can be set arbitrarily, and can be a part or all of the time domain corresponding to the switching control signal acquired by the switching control signal acquisition unit 3.

[0126] To simplify the description, an example is described below in which the same number (N each) of on-times and off-times are extracted. However, in reality, there may be a situation in which only one of the on-times and off-times is extracted from the edge pulses during the noise analysis target period, resulting in a difference in the number of on-times and off-times.

[0127] The phase conversion unit 14a sets the i-th connection time ton(i)=t, and calculates exp(-j·2πft) in order to give the noise source spectrum a phase difference caused by the difference in the connection time. Similarly, the phase conversion unit 14b sets the i-th disconnection time toff(i)=t, and calculates exp(-j·2πft) in order to express the time difference of disconnection by the phase difference. Exp(-j·2πft) calculated corresponding to the connection time ton(i) and the disconnection time toff(i) respectively corresponds to an embodiment of "a plurality of phase difference information". By multiplying these phase difference information with the noise source spectrum, the phase changes of multiple connection times and multiple disconnection times can be included in the noise source spectrum.

[0128] The multiplication unit 15 outputs the multiplication results of the output value (on observation noise) of the multiplication unit 12 and the phase difference information of the multiple on times from the phase conversion unit 14a. Thus, the on observation noise NSon(i) corresponding to the i-th (i: 1 to N) on time ton(i) is calculated.

[0129] Similarly, the multiplication unit 16 outputs the multiplication results of the output value (disconnection observation noise) of the multiplication unit 13 and the phase difference information of the multiple disconnection times from the phase conversion unit 14b. Thus, the disconnection observation noise NSoff(i) corresponding to the i-th (i: 1 to N) disconnection time toff(i) is calculated.

[0130] The on-state observation noise NSonn(i) and the off-state observation noise NSoff(i) correspond to an embodiment of “multiple multiplication values”, which are multiplication values ​​of multiple noise source spectra and noise transfer functions (Gon or Goff) obtained by phase-transforming the noise source spectrum (on-state noise source spectrum SPNon or off-state noise source spectrum SPNoff) according to the phase difference information corresponding to the on-state instant ton(i) and the off-state instant toff(i). In addition, Fig.10 , Fig.11 In the embodiment, even if the positions of the multiplication units 12, 13 and the multiplication units 15, 16 are swapped (before or after the multiplication operation), the same "multiplication values" can be calculated, and the function of the "first multiplication unit" is realized by the multiplication units 12, 13, 15, 16.

[0131] The adding unit 17 calculates the observed noise NS(i) of the i-th pulse (i.e., 1 time of on and off) by adding the observed noise NSon(i) of the on-state from the multiplying unit 15 and the observed noise NSoff(i) of the off-state from the multiplying unit 16. Thus, the observed noises NS(1) to NS(N) of the 1st to Nth pulses are calculated, i=1 to N.

[0132] The adding unit 18 adds the observation noises NS(1) to NS(N) calculated by the adding unit 17 and outputs the observation noise calculation result RTNS. The observation noise calculation result RTNS is expressed as Fig. 9 The noise source spectrum shown in FIG. 1 is a collection of data on noise intensity (eg, noise voltage [dBV]) at each frequency.

[0133] In addition, the weights between the multiple pulses may be changed for addition. For example, a weighting coefficient kw(i) may be introduced, and the multiplication value of the observation noise NS(i) from the adding unit 17 and the weighting coefficient kw(i) may be added up by the adding unit 18. As an example, the weighting coefficient kw(i) may be set to have a large value in the center of the noise analysis target period and a small value in the edge portion.

[0134] exist Fig.11In the embodiment, the switch control signal acquisition unit 3 corresponds to an embodiment of the "first acquisition unit", and the noise transfer function acquisition unit 4 corresponds to an embodiment of the "second acquisition unit". In addition, the adder units 17 and 18 implement the function of the "first adder". In addition, the on time ton(i) and the off time toff(i) correspond to the "multiple occurrence times" when the semiconductor element is switched on and off multiple times.

[0135] The time range setting unit 14 calculates the noise analysis target period corresponding to one of the noise analysis target periods. Fig.11 Thus, when the time range setting unit 14 sets a plurality of noise analysis target periods, the observed noise calculation result RTNS can be calculated for each of the plurality of noise analysis target periods. In this case, the noise analysis function unit 11 may further include a function of performing statistical calculation (calculating an average value, a maximum value, a minimum value, etc.) on the calculated plurality of observed noise calculation results RTNS to obtain the observed noise calculation result RTNS from the noise analysis function unit 11. Figure 2 ) outputs the result obtained through statistical calculation as the final observation noise calculation result RTNS.

[0136] In addition, Fig.11 In the configuration example of , it is confirmed that the same observation noise calculation result RTNS is obtained even if the order of addition operations performed by the adder 17 and the adder 18 is changed. That is, a configuration may be adopted in which the adder 17 performs the operation of adding the on-noise and the off-noise to the N-times addition result obtained by the adder 18.

[0137] Fig.12 FIG. 2 shows a configuration example of an observation noise calculation unit 11 for calculating observation noise from a plurality of noise sources (semiconductor elements). Figure 3 In the analysis target circuit 200 shown in the example, when calculating the observed noise by treating the semiconductor elements 101 and 102 as independent noise sources, the following can be applied: Fig.12 The observation noise calculation section is shown.

[0138] like Fig.12 As shown, the observation noise calculation unit 11 includes a total calculation unit 10X (with Fig.11 The same structure) and the adding section 19. From each total calculation section 10X, the observation noise calculation result is calculated for each noise source as the output of the adding section 18.

[0139] The adding unit 19 adds the observed noise calculation results from the summing calculation unit 10X provided for each noise source, and outputs the sum of the observed noise from the plurality of noise sources as the observed noise calculation result RTNS. Thus, the observed noise calculation result RTNS can be obtained corresponding to any number of noise sources. That is, the adding unit 19 corresponds to an embodiment of the "second adding unit".

[0140] As described above, according to the noise analysis technology of the first embodiment, it is possible to perform noise analysis in which the on and off of the semiconductor element in a plurality of pulses including information on changes in the on-period length and the off-period length is used as a noise source, while suppressing the time width of the object of Fourier transform to the minimum number of pulses (representatively 1 time). Thus, without directly using a plurality of pulses as the object of Fourier transform to increase the time required for Fourier transform, the behavior of the change in the on-period length and the off-period length of the semiconductor element can be reflected, and noise analysis can be performed quickly and accurately.

[0141] The basic configuration of the noise analysis for one or more noise sources has been described above. Modifications and detailed specific examples of the noise analysis technique of the first embodiment will be described as appropriate below.

[0142] Fig.13 Shown with Fig.10 The observed noise calculation unit 10 ( Figure 2 ) is a modification example of the structure.

[0143] Reference Fig.13 The noise transfer function acquisition unit 4 may acquire the noise transfer function Gcmn set in common for both the on and off times. In this case, the observed noise calculation unit 10 may be configured to include a total calculation unit 10Y and a multiplication unit 12Y.

[0144] The total calculation unit 10Y has Fig.11 The total calculation unit 10X shown in FIG. 1 is a structure in which the multiplication units 12 and 13 are deleted. The multiplication unit 12Y is configured to Fig.11 The output value of the adding unit 18 is multiplied by the noise transfer function Gcmn. Fig.11 In the calculation, the observation noise result RTNS of Gon=Goff=Gcmn can be obtained.

[0145] In addition, although Fig.11 In the structure of , Gon = Goff = Gcmn is input to the multiplication units 12 and 13, and the same observation noise calculation result RTNS as above can be obtained, but by adopting Fig.13 The structure can reduce one multiplication operation, thus shortening the noise analysis time.

[0146] Fig.14 Show Figure 2 A modification of the noise analysis function unit 1 is shown.

[0147] exist Figure 2 In the structure, the Fourier transform units 23 and 24 are provided in the noise analysis function unit 1 to obtain the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff of the on-noise transient waveform and the off-noise transient waveform.

[0148] In contrast, Fig.14 In the modified example, the noise analysis function unit 1 receives input of the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff obtained by Fourier transforming the on-noise transient waveform and the off-noise transient waveform in advance.

[0149] In this case, the on-noise source spectrum acquisition unit 25 and the off-noise source spectrum acquisition unit 26 acquire the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff input to the noise analysis function unit 1. Fig.14 In the embodiment, the on-noise source spectrum acquisition unit 25 and the off-noise source spectrum acquisition unit 26 correspond to an embodiment of the “third acquisition unit”.

[0150] By inputting the acquired on-noise source spectrum SPNon and off-noise source spectrum SPNoff into the observation noise calculation unit 10, it is possible to use Fig.10 or Fig.13 The structure calculates the observation noise calculation result RTNS.

[0151] Alternatively, you can also Figure 2 and Fig.14 In this case, the following structure can be used: according to the result of the automatic determination, the noise source data and the noise source disconnection data input to the noise analysis function unit 1 are selected. Figure 2 The on-noise source spectrum SPNon and the off-noise source spectrum SPNoff are input to the observation noise calculation unit 10 through the path of the Fourier transform units 23 and 24 and the path bypassing the Fourier transform units 23 and 24. Thus, both the transient waveform (time domain) and the spectrum (frequency domain) can be used as the on-noise source data and the off-noise source data in the noise analysis.

[0152] In addition, Figure 4 and Figure 5 In the example, t1 and t2 are used as the reference for the transient waveform, but sometimes the time point of the input transient waveform data may deviate from t1 and t2 and the zero time. In this case, you can also apply Fig.15The structure shown is used to automatically detect the occurrence time of the connection or the occurrence time of the disconnection from the transient waveform and automatically perform the correction process of the timing deviation.

[0153] Reference Fig.15 , the on-state transient waveform (eg Figure 4 ) is input to the time deviation detection function unit 27a. The time deviation detection function unit 27a takes the initial time of the transient waveform data ( Figure 4 The voltage value (or current value) at the origin time in the circuit is saved as the initial value. In addition, at each subsequent time, the time deviation detection function unit 27a compares the difference between the voltage value (or current value) at that time and the initial value with a predetermined threshold value, and detects that a connection has occurred when the absolute value of the difference is greater than the threshold value. The threshold value can be, for example, Figure 4 The method of detecting the turn-on near t1 is used to determine.

[0154] The time deviation detection function unit 27a detects the time difference between the zero time (the time corresponding to the origin) and the time when the switch-on is detected as the time deviation amount τ. The time deviation amount τ is assumed to be a positive value (τ>0) when the switch-on occurs later than the reference zero time, and a negative value (τ<0) when the switch-on occurs earlier than the zero time, so as to cope with the situation.

[0155] The timing deviation correction function unit 28 a inputs the switching-on transient waveform obtained by correcting the time axis data of the switching-on transient waveform acquired by the switching-on transient waveform acquisition unit 21 according to the timing deviation amount τ detected by the timing deviation detection function unit 27 a to the Fourier transformation unit 23 .

[0156] Similarly, for the disconnection transient waveform (for example Figure 5 ), a time deviation detection function unit 27b and a time deviation correction function unit 28b are also provided which are the same as the time deviation detection function unit 27a and the time deviation correction function unit 28a. That is, the time deviation detection function unit 27b detects the time difference between the zero time (the time corresponding to the origin) and the time when the disconnection is detected as the time deviation amount τ. In addition, although the time deviation amount τ of the connection (time deviation detection function unit 27a) and the time deviation amount τ of the disconnection (time deviation detection function unit 27b) are indicated by the same figure mark for the sake of simplicity, they can actually be different values. Regarding the time deviation amount τ of the disconnection, it can also be set to a positive value (τ>0) when the disconnection occurs later than the zero time serving as the reference, and can be set to a negative value (τ<0) when the disconnection occurs earlier than the zero time.

[0157] By adopting this structure, even if the voltage waveform or current waveform that makes the turn-on time and the turn-off time zero is not input, the time deviation between the turn-on time and the turn-off time can be automatically corrected to obtain transient waveform data for obtaining the turn-on noise source spectrum SPNon and the turn-off noise source spectrum SPNoff.

[0158] Or you can Fig.16 As shown, the timing deviation correction functional units 28a and 28b are arranged at the subsequent stage of the Fourier transform units 23 and 24. In this case, the timing deviation correction functional units 28a and 28b are configured to multiply the output of the Fourier transform units 23 and 24 by exp(-j·2πf(-τ))=exp(j·2πfτ) according to the timing deviation amount τ detected by the timing deviation detection functional units 27a and 27b. Fig.16 The structural example can also be obtained with Fig.15 The same applies to the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff.

[0159] Although, for example, Fig.11 In the frequency domain, the phase conversion is performed by multiplying the exp(-j·2πft) calculated corresponding to the on time ton(i) and the off time toff(i), respectively. Fig.34 Variations of the illustrated structure are also possible in which the phase transformation is performed in the time domain.

[0160] Fig.34 A block diagram illustrating a variation of performing phase transformation in the time domain.

[0161] Reference Fig.34 , the on-transient waveform acquired by the on-transient waveform acquisition unit 21 is input to the phase conversion unit 14c. The phase conversion unit 14c receives the on-time ton(i) extracted by the time range setting unit 14, and outputs the on-transient waveform shifted on the time axis according to the time difference corresponding to each on-time ton(i). In this way, the on-transient waveform (waveform data) reflecting the phase difference in the time domain is input to the Fourier transformation unit 23. The Fourier transformation unit 23 performs Fourier transformation on the on-transient waveform (waveform data) of each on-time ton(i) output from the phase conversion unit 14c.

[0162] Similarly, the disconnection transient waveform acquired by the disconnection transient waveform acquisition unit 22 is input to the phase conversion unit 14d. The phase conversion unit 14d receives the disconnection time toff(i) extracted by the time range setting unit 14, and outputs the disconnection transient waveform shifted on the time axis according to the time difference corresponding to each disconnection time toff(i). The Fourier transformation unit 24 performs Fourier transformation on the disconnection transient waveform (waveform data) of each disconnection time toff(i) from the phase conversion unit 14d, which reflects the phase difference in the time domain.

[0163] Fig.11 The total calculation unit 10X shown in the figure can be modified as follows: instead of the phase conversion units 14a, 14b and the multiplication units 15, 16, an Fig.34 In the structure, the outputs of the Fourier transform units 23 and 24 are multiplied by the noise transfer functions Gon and Goff by the multiplication units 12 and 13 to calculate the off-state observation noise NSoff(i) and the on-state observation noise NSon(i).

[0164] Even if using Fig.34 In the modified example, the phase transformation based on the phase difference information is performed in the time domain, and the entire pulse including the on and off pulses may not be used as the object of the Fourier transform, so a certain effect can be obtained in reducing the number of time steps used as the object of the Fourier transform. However, the Fourier transform after the phase transformation requires the Fourier transform corresponding to the number of occurrences of the on and off, so if the phase transformation is performed by multiplication in the frequency domain, the effect of reducing the calculation burden of the Fourier transform becomes better.

[0165] Next, we will use the noise transfer function as an S parameter. Figure 17~Figure 21 The following describes an example of the connection of the noise transfer function. As mentioned above, the noise transfer function means the transfer function of the noise in the frequency domain on the propagation path from the noise source to the noise observation point.

[0166] Fig.17 As a first example, a wiring diagram is shown when there are two noise sources and two noise observation points.

[0167] like Fig.17 As shown, the noise transfer function 81 has four ports Prt1 to Prt4, and the ports Prt1 to Prt4 are respectively connected to the first noise source 71, the second noise source 72, the first noise observation point 73, and the second noise observation point 74. The first noise source 71 and the second noise source 72 correspond to, for example, Figure 3 The upper arm semiconductor element 101 and the lower arm semiconductor element 102 in the illustrated analysis target circuit 200. The number of ports is not limited to four, but may be any number.

[0168] Fig.18As a second example, a wiring diagram is shown when the noise source and the noise observation point are each single.

[0169] exist Fig.18 In FIG. 8 , the noise transfer function 81 has two ports Prt1 and Prt2 . The port Prt1 is connected to the first noise source 71 , and the port Prt2 is connected to the first noise observation point 73 .

[0170] The noise transfer function (Gon, Goff, Gcmn) used for noise analysis can be acquired by deriving a transfer function between a noise source to be analyzed and a noise observation point in advance and reading the transfer function data by the noise transfer function acquisition unit 4 .

[0171] Fig.19 As a third example, a connection diagram is shown in which the transfer function is divided into two via a relay point.

[0172] like Fig.19 As shown in FIG. 1 , the transfer function between the first noise source 71 and the first noise observation point 73 is divided into a first noise transfer function 81a between the first noise source 71 and the relay point 82 and a second noise transfer function 81b between the first noise observation point 73 and the relay point 82. Fig.19 In FIG. 8 , the first noise source 71 and the first noise observation point 73 are divided into two propagation paths via the relay point 82 , and the first noise transfer function 81 a and the second noise transfer function 81 b correspond to the transfer functions of the two propagation paths, respectively.

[0173] The first noise transfer function 81a and the second noise transfer function 81b each have two ports Prt1 and Prt2. The ports Prt1 and Prt2 of the first noise transfer function 81a are connected to the first noise source 71 and the relay point 82, respectively. The ports Prt1 and Prt2 of the second noise transfer function 81b are connected to the relay point 82 and the first noise observation point 73, respectively.

[0174] Fig. 20 As a fourth example, a connection diagram is shown in which the transfer function is divided into two via a plurality of relay points.

[0175] like Fig. 20 As shown, the transfer function between the first noise source 71 and the first noise observation point 73 is divided into a first noise transfer function 81a between the first noise source 71 and the relay points 83 and 84 and a second noise transfer function 81b between the first noise observation point 73 and the relay points 82 and 83. Fig. 20 In FIG. 7 , the first noise source 71 and the first noise observation point 73 are divided into two propagation paths via the relay points 83 and 84 , and the first noise transfer function 81 a and the second noise transfer function 81 b correspond to the transfer functions of the two propagation paths, respectively.

[0176] The first noise transfer function 81a and the second noise transfer function 81b each have three ports Prt1 to Prt3. In the first noise transfer function 81a, the port Prt1 is connected to the first noise source 71, the port Prt2 is connected to the relay point 83, and the port Prt3 is connected to the relay point 84. In addition, in the second noise transfer function 81b, the port Prt1 is connected to the relay point 83, the port Prt2 is connected to the first noise observation point 73, and the port Prt3 is connected to the relay point 84.

[0177] like Fig.19 and Fig. 20 As shown in the figure, when the noise transfer function between the noise source to be analyzed and the noise observation point is divided into multiple cases, by applying Fig.21 The structure can obtain the noise transfer function (Gon, Goff, Gcmn) used in the noise analysis function unit 1.

[0178] Reference Fig.21 , the transfer function integration section 4X is input Fig.19 and Fig. 20 The noise transfer functions Gon and Goff are outputted by using the data of the first noise transfer function 81a and the second noise transfer function 82a in the noise analysis function unit 1. The transfer function integration unit 4X is arranged at the subsequent stage of the noise transfer function acquisition unit 4, thereby being able to acquire the noise transfer function used in the noise analysis function unit 1 by integrating the divided transfer functions.

[0179] Fig.21 The noise transfer functions for the on and off noise sources are shown to be independent. Fig.10 Similarly, the noise transfer function for the on-noise source and the off-noise source is the same. Fig.13 In the structure of , the transfer function integration unit 4X can also be applied to obtain the noise transfer function Gcmn.

[0180] By dividing the noise transfer function into a plurality of parts, the noise transfer function can be derived independently for each section. Thus, even if the design of a part of the section is changed, it is only necessary to re-derive the noise transfer function corresponding to the changed section, without re-deriving the entire noise transfer function. As a result, the burden of preparing the data of the noise transfer function can be reduced.

[0181] In addition, the number of divisions of the noise transfer function is not limited to 2, and may be divided into any number of divisions of 3 or more. Fig. 20Similarly, by appropriately integrating the transfer functions of the plurality of propagation paths divided between the noise source to be analyzed and the noise observation point, it is possible to obtain the noise transfer function (Gon, Goff, Gcmn) used in the noise analysis function unit 1 .

[0182] In addition, in the interface for wiring setting provided in the noise analysis program, the connection correspondence between each port of the noise transfer function and the noise source, the noise observation point or the relay point can be defined by a wiring diagram or a correspondence table. The noise transfer function acquisition unit 4 can acquire the noise transfer function (Gon, Goff, Gcmn) used for noise analysis by inputting the propagation path between the noise source to be analyzed and the noise observation point into the above interface and configuring the transfer function integration unit 4X as needed.

[0183] Next, other examples of the noise analysis target circuit and examples of the observed noise calculation results obtained by the noise analysis device of the first embodiment will be further described.

[0184] Fig. 22 To illustrate and Figure 3 A circuit diagram of another example of a different noise analysis target.

[0185] exist Fig. 22 In the example, the analysis target circuit 200 has a structure and Figure 3 The upper arm semiconductor element 101 and the lower arm semiconductor element 102 of the same arm are connected in series between the output positive terminal 301 and the output negative terminal 302 .

[0186] The intermediate terminal 205 corresponding to the connection point between the upper arm semiconductor element 101 and the lower arm semiconductor element 102 is connected to the input positive terminal 201 via the reactor 304. Figure 3 Similarly, the input negative terminal 202 is connected to the low potential side terminal of the lower arm semiconductor element 102, and the capacitor 204 is connected between the input positive terminal 201 and the input negative terminal 202. The output negative terminal 302 and the input negative terminal 202 are connected to the low potential side terminal of the lower arm semiconductor element 102.

[0187] The load 303 is connected between the output positive terminal 301 and the output negative terminal 302. Fig. 22 In the structure of , the lower branch semiconductor element 102 mainly works as a transistor, and the upper branch semiconductor element 101 mainly works as a diode. Figure 3As also described in , the analysis object circuit 200 may include a set of upper branch semiconductor elements and lower branch semiconductor elements connected in series in a plurality of branches, and the number of semiconductor elements connected in series is not limited to 2, but may be any number. Alternatively, the analysis object circuit 200 may be a DCDC converter or an ACDC converter.

[0188] Fig.23 Another example of the noise analysis target is shown.

[0189] exist Fig.23 In the example, the analysis object circuit 200 has a first branch 401, a second branch 402, and a third branch 403 connected in parallel between the input positive terminal 201 and the input negative terminal 202. The first branch 401, the second branch 402, and the third branch 403 each include an upper branch semiconductor element and a lower branch semiconductor element connected in series between the input positive terminal 201 and the input negative terminal 202. In each of the first branch 401, the second branch 402, and the third branch 403, intermediate terminals 411 to 413 corresponding to the connection points of the upper branch semiconductor element and the lower branch semiconductor element are connected to the AC load 405. That is, Fig.23 The analysis object circuit 200 operates as a three-phase inverter.

[0190] As described above, the analysis target circuit 200 may be an inverter that performs DC-AC conversion, and the number of phases of the inverter is not limited to three, but may be any number. In addition, the number of semiconductor elements connected in series in each branch is not limited to two, but may be any number.

[0191] Fig.24 Shows the Fig.23 The example of the observed noise calculation result of the switching control of the analysis object circuit (three-phase inverter) shown in FIG. Here, the noise analysis is performed by switching the semiconductor elements (noise sources) of each phase branch of the three-phase inverter by PWM control using an AC waveform as a modulation signal. In addition, the switching frequency of each semiconductor element under PWM control is set to 10 [kHz]. In the PWM control of the inverter, it is known that Figure 7 Similarly to the switching control signal shown, the on-period length and the off-period length of the switching control signal of each semiconductor element change.

[0192] Fig.24 The noise terminal voltage [dBV] indicating the noise intensity at each frequency obtained as the observed noise calculation result RTNS is plotted. Fig.25 Show Fig.24 A magnified image of the 0.1[MHz]~0.5[MHz] area.

[0193] Under switching control with the switching frequency fixed at 10 [kHz], when the on-period length is constant, a peak of the noise spectrum occurs at an integer multiple of 10 [kHz], so that concavities and convexities occur at 10 [kHz] intervals in the spectrum.

[0194] However, according to the three-phase inverter ( Fig.23 ) is the noise analysis of the embodiment 1 of the object, such as Fig.25 As shown, the above-mentioned unevenness at intervals of 10 [kHz] is not generated.

[0195] That is, it is generally understood that according to the above-mentioned embodiment 1, it is possible not to Figure 7 The plurality of pulses included in the gate signal shown are directly subjected to Fourier transform, thereby realizing noise analysis of switching control associated with changes in the on-period length and the off-period length. Implementation method 2.

[0196] In the first embodiment, the ON transient waveform and the OFF transient waveform are input separately to the noise analysis function unit 1 , but in the second embodiment, a configuration in which the ON transient waveform and the OFF transient waveform can be separated inside the noise analysis function unit 1 will be described.

[0197] Fig.26 This is a block diagram for explaining a configuration example of a noise analysis device according to the second embodiment.

[0198] Reference Fig.26 The noise analysis function unit 1 of the noise analysis device of the second embodiment and Figure 2 Compared with the configuration of the first embodiment shown, the difference lies in that a transient waveform acquisition unit 20 is provided in place of the ON transient waveform acquisition unit 21 and the OFF transient waveform acquisition unit 22 , and an ON / OFF separation unit 29 is further provided.

[0199] The transient waveform acquisition unit 20 acquires a transient waveform including both an ON transient waveform and an OFF transient waveform. That is, in the second embodiment, it is not necessary to extract the ON transient waveform and the OFF transient waveform from the transient waveform input to the noise analysis function unit 1 (noise analysis device).

[0200] Fig. 27 Show Fig.26 The configuration example of the on / off separation unit 29 is shown.

[0201] Reference Fig. 27 The on / off separation unit 29 includes an on timing detection unit 31 , an off timing detection unit 32 , an on transient waveform output unit 33 , and an off transient waveform output unit 34 .

[0202] The ON timing detection unit 31 and the voltage value (for example, Figure 4 and Figure 5 The on-time of the semiconductor element is detected corresponding to the moment when the Vtr in the on-time detection section 31 is reduced to cross the predetermined threshold. The on-time transient waveform output section 33 extracts the transient waveform of a certain period including the on-time detected by the on-time detection section 31 from the transient waveform obtained by the transient waveform acquisition section 20 and outputs the on-time transient waveform.

[0203] The disconnection timing detection unit 32 is connected to a voltage value (for example, Figure 4 and Figure 5 The disconnection timing of the semiconductor element is detected corresponding to the moment when Vtr in the disconnection timing detector 32 rises to cross the predetermined threshold. The disconnection transient waveform output unit 34 extracts the transient waveform of a certain period including the disconnection timing detected by the disconnection timing detector 32 from the transient waveform obtained by the transient waveform acquisition unit 20 and outputs the disconnection transient waveform.

[0204] The on-transient waveform output unit 33 and the off-transient waveform output unit 34 respectively output the Figure 2 The outputted on-transient waveform and off-transient waveform are respectively inputted into Fig.26 Alternatively, the on-transient waveform and the off-transient waveform output from the on-transient waveform output unit 33 and the off-transient waveform output unit 34 may be input to Fig.34 Phase conversion units 14c, 14d.

[0205] In addition, the transient waveform contains current values ​​that change over time (e.g. Figure 6 In the case of Itr in, the on-time detection unit 31 can be configured to detect the on-time in response to the rise of the current value crossing the threshold, and the off-time detection unit 32 can be configured to detect the off-time in response to the decrease of the current value crossing the threshold.

[0206] Refer again Fig.26 , except for the structure for obtaining the on-transient waveform and the off-transient waveform, it is the same as the first embodiment, so the detailed description will not be repeated.

[0207] As described above, according to the noise analysis technique of the second embodiment, it is possible to eliminate the need for separate steps of preparing an on-transient waveform and an off-transient waveform for the transient waveform input to the noise analysis function unit 1 (noise analysis device). Implementation method 3.

[0208] Generally speaking, it is known that the higher the resolution bandwidth (Resolution BandWidth) of a noise measuring instrument for measuring noise is compared to the switching frequency of a semiconductor element as a noise source, the larger the measured noise will appear. In Embodiment 3, a noise analysis technique that takes into account the resolution bandwidth assumed at a noise observation point is described.

[0209] Fig.28 This is a block diagram for explaining a configuration example of a noise analysis device according to a third embodiment.

[0210] Fig.28 and Figure 2 The difference is that the noise analysis function unit 1 of the noise analysis device of the third embodiment further includes a measuring device parameter acquisition unit 5 .

[0211] Furthermore, in order to perform noise analysis reflecting the information of the resolution bandwidth assumed at the noise observation point acquired by the measuring device parameter acquisition unit 5, the observation noise calculation unit 10 further includes: Fig.29 Typically, the information includes the resolution bandwidth of the noise measuring instrument used at the noise observation point. As the noise measuring instrument, a spectrum analyzer or an EMI (Electro Magnetic Interference) receiver can be used. Fig.28 The structure and operation of other parts of Figure 2 (Implementation 1) is the same, so the detailed description will not be repeated.

[0212] Fig.29 This is a block diagram for explaining a function added to the observation noise calculation unit 10 in the noise analysis of the third embodiment.

[0213] Reference Fig.29 The observation noise calculation unit 10 of the third embodiment further includes a weighted calculation function unit 40. The weighted calculation function unit 40 includes a window function calculation unit 41, a weight coefficient setting unit 42, and multiplication units 43 and 44.

[0214] The window function calculation unit 41 calculates the window function based on the window function from the time range setting unit 14 ( Fig.11 ) is used to set the window function w(t) based on the information of the start time Tstr to the end time Tend of the noise analysis target period. Outside the noise analysis target period, the window function w(t) is set to w(t) = 0. The window function w(t) is set to a shape in which the value at the edge of the noise analysis target period is small and the value at the center is large.

[0215] In Embodiment 3, the shape of the window function w(t) is set to match the frequency resolution of the noise measurement performed by the noise measurement device or the like based on the resolution bandwidth acquired by the measurement device parameter acquisition unit 5. For example, when the window function w(t) is Fourier transformed according to a predetermined comprehensive selectivity characteristic, the shape of the window function w(t) can be determined so that the DC component is 0 [dB] and the frequency component of the half value of the resolution bandwidth is -6 [dB] or -3 [dB].

[0216] The window function w(t) set by the window function calculation unit 41 and the window function w(t) from the time range setting unit 14 ( Fig.11 ) is input to the weighting coefficient setting unit 42.

[0217] The weighting coefficient setting unit 42 outputs the value of the window function w(t) at each on time ton(i) as the weighting coefficient WGon(i) at each on time. Similarly, the weighting coefficient setting unit 42 outputs the value of the window function w(t) at each off time toff(i) as the weighting coefficient WGoff(i) at each off time.

[0218] The multiplication unit 43 multiplies the on-noise source data at the on-time ton(i) by the corresponding weighting coefficient WGon(i). Similarly, the multiplication unit 44 multiplies the off-noise source data at the off-time toff(i) by the corresponding weighting coefficient WGoff(i).

[0219] exist Fig.29 In the above, the on-noise source data includes data after the information for distinguishing the on-time ton(i) (the output value of the phase conversion unit 14a) is reflected on the on-noise source spectrum SPNon in the observed noise calculation unit 10. Similarly, the off-noise source data includes data after the information for distinguishing the off-time toff(i) (the output value of the phase conversion unit 14b) is reflected on the off-noise source spectrum SPNoff in the observed noise calculation unit 10.

[0220] exist Fig.29 In FIG. 1 , the measuring device parameter acquiring unit 5 corresponds to an embodiment of the “fourth acquiring unit.” In addition, the multiplying units 43 and 44 realize the function of the “second multiplying unit.”

[0221] In addition, the weighting coefficients WGon(i) and WGoff(i) can be multiplied by the noise source data in the time domain, so that the weighting coefficients WGon(i) and WGoff(i) are reflected in the on-state observation noise NSon(i) and the off-state observation noise NSoff(i). Fig.34In the structure, the weighting coefficients WGon(i) and Goff(i) of the turn-on time ton(i) and the turn-off time toff(i) can be input to the phase conversion units 14c and 14d. Then, the phase conversion units 14c and 14d can output the multiplication results of the turn-on transient waveform and the turn-off transient waveform given a phase difference in the time domain and the weighting coefficients WGon(i) and Goff(i) to the Fourier transformation units 23 and 24.

[0222] In addition, regarding the weighting coefficients WGon(i) and Goff(i) reflected in the frequency domain, Fig.29 For example, even if the multiplication units 43 and 44 (second multiplication unit) are Fig.11 The multiplication units 12, 13, 15, 16 (first multiplication unit) shown in the above examples can be interchanged in order, and the weighting coefficients WGon(i) and WGoff(i) can also be reflected in the multiplication values ​​calculated by the multiplication units 12, 13, 15, 16. Fig.11 As is apparent from the description in, etc., these multiplication values ​​can be multiplied by the noise transfer function in an arbitrary process.

[0223] As a result, the adder 17 can calculate the observed noise NS(i) of the i-th pulse by multiplying the weighting coefficients WGon(i) and WGoff(i) corresponding to the shape of the window function w(t). Thus, the finally calculated observed noise calculation result RTNS can be calculated with the weights considering the positions of each on time and each off time within the noise analysis object period. In particular, according to the third embodiment, by reflecting the resolution bandwidth of the noise measuring device in the setting of the weighting coefficient, the analysis noise calculation result considering the resolution bandwidth can be obtained.

[0224] In addition, it is confirmed that Fig.29 In the configuration example, even if the order of addition performed by the adders 17 and 18 is changed, the same observed noise calculation result RTNS is obtained. That is, a configuration can also be adopted in which the adder 17 performs a calculation of adding the on-noise and off-noise to the N-times addition result obtained by the adder 18.

[0225] Fig.30 This is a spectrum diagram showing an example of the observation noise calculation result obtained by the noise analysis according to the third embodiment. Fig.30 The observed noise calculation results RTNS are plotted with a resolution bandwidth of 9 [kHz] for frequencies below 30 [MHz] and a resolution bandwidth of 120 [kHz] for frequencies above 30 [MHz]. In addition, the switching frequency of the semiconductor device, which is the noise source, is plotted against Fig.24 The same is 10 [kHz].

[0226] like Fig.30As shown in FIG. 1 , the calculation result shows that the noise is large in the frequency domain where the resolution bandwidth is 30 [MHz] or more higher than the switching frequency. Based on this result, it is generally understood that high-precision noise analysis can be performed taking into account the influence of the resolution bandwidth of the noise measuring instrument.

[0227] In addition, Fig.29 In the embodiment 1 or 2, a configuration in which the window function w(t) is set without reflecting the parameter (resolution bandwidth) of the noise measurement can be combined. In this case, the noise analysis can be made more accurate by performing weighting in consideration of the position of each on time and each off time in the noise analysis target period. Implementation method 4.

[0228] In the first to third embodiments, the calculation of the observation noise calculation result RTNS is performed by making the on-noise source spectrum SPNon of each on-time ton(i) common and making the off-noise source spectrum SPNoff of each off-time toff(i) common.

[0229] On the other hand, the noise source spectrum generated by the switching of the semiconductor element changes depending on the current (load current) being switched. For example, when the load current becomes smaller, the current change of the semiconductor element during switching becomes smaller, and the time when the voltage change of the semiconductor element starts and the gradient of the voltage change change accordingly. Therefore, in Embodiment 4, a noise analysis technology that further reflects the load current at the time of switching on and off of the semiconductor element is described.

[0230] Fig.31 This is a block diagram for explaining a configuration example of a noise analysis device according to a fourth embodiment.

[0231] Reference Fig.31 The noise analysis function unit 1 of the noise analysis device of the fourth embodiment and Figure 2 Compared with the configuration of the first embodiment shown, the present invention is different in that a load current waveform acquisition unit 6 is further provided. The load current waveform acquisition unit 6 acquires a load current waveform (time axis) in a time range including the noise analysis target period.

[0232] In the fourth embodiment, the ON transient waveform acquisition unit 21 and the OFF transient waveform acquisition unit 22 acquire a plurality of OFF transient waveforms and a plurality of ON transient waveforms having different load currents. Fig.31 In the above, J (J: a natural number greater than or equal to 2) ON transient waveforms and J OFF transient waveforms are acquired and input to the Fourier transform units 23 and 24, respectively. As a result, J ON noise source spectra and J OFF noise source spectra with different load current levels are input to the observed noise calculation unit 10.

[0233] In the fourth embodiment, the observation noise calculation unit 10 is added with Fig.32 The function of the noise source spectrum correction unit 60 is shown.

[0234] Reference Fig.32 The noise source spectrum correction unit 60 includes load current value acquisition units 61 and 62 and interpolation calculation function units 65 and 66 .

[0235] The load current value acquisition unit 61 receives the load current waveform (time axis) acquired by the load current waveform acquisition unit 6 and the time range setting unit 14 ( Fig.11 The load current value acquisition unit 61 outputs the current value of the load current waveform at each of the on-times ton(i) as the load current value X(i) at each on-time. The load current value X(i) is input to the interpolation calculation function unit 65.

[0236] Furthermore, the interpolation calculation function unit 65 receives input of the on-noise source spectra of the J different load current values ​​X1 to XJ from the Fourier transform unit 23 .

[0237] The interpolation calculation function unit 65 outputs an on-state noise source spectrum SPNon corresponding to the load current value X(i) from the on-state noise source spectrum of each of the load current values ​​X1 to XJ based on the relationship between the load current values ​​X1 to XJ and the input load current value X(i).

[0238] For example, the on-state noise source spectrum SPNon corresponding to the load current value X(i) can be obtained by linear interpolation based on interpolation or extrapolation using the on-state noise source spectra corresponding to the two load current values ​​closest to the load current value X(i) among the load current values ​​X1 to XJ.

[0239] As a result, the interpolation calculation function unit 65 can calculate the on-state noise spectrum SPNon depending on the load current value X(i) at each on-state time ton(i).

[0240] Similarly, the load current waveform (time axis) from the load current waveform acquisition unit 6 and the time range setting unit 14 ( Fig.11 ) is input to the load current value acquisition unit 62. The load current value acquisition unit 62 outputs the current value of the load current waveform at the disconnection time toff(i) as the load current value X(i) at each disconnection time. The load current value X(i) is input to the interpolation calculation function unit 66.

[0241] Furthermore, the interpolation calculation function unit 66 receives the off-noise source spectra of each of the J different load current values ​​X1 to XJ from the Fourier transform unit 24 .

[0242] The interpolation calculation function unit 66 outputs an off-noise source spectrum SPNoff corresponding to the load current value X(i) from the off-noise source spectrum of each of the load current values ​​X1 to XJ based on the relationship between the load current values ​​X1 to XJ and the input load current value X(i).

[0243] For example, the off-noise source spectrum SPNoff corresponding to the load current value X(i) can be obtained by linear interpolation based on interpolation or extrapolation using the off-noise source spectra corresponding to the two load current values ​​closest to the load current value X(i) among the load current values ​​X1 to XJ.

[0244] As a result, the interpolation calculation function unit 66 can calculate the off-noise source spectrum SPNoff depending on the load current value X(i) at each off-time toff(i). In addition, the interpolation calculation performed by the interpolation calculation function units 65 and 66 is not limited to the above-mentioned linear interpolation. For example, the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff for each load current value X(i) can also be obtained by n-order spline interpolation (n: a natural number where n>2).

[0245] As described above, in the fourth embodiment, the noise source spectrum correction unit 60 can calculate the on-state noise source spectrum SPNon and the off-state noise source spectrum SPNoff based on the load current at each timing for each on-time ton(i) and each off-time toff(i).

[0246] According to the noise analysis technology of the fourth embodiment, the following operation is performed: the observation noise calculation result RTNS described in the first to third embodiments is derived using the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff obtained by the noise source spectrum correction unit 60. At this time, Fig.11 The on-noise source spectrum SPNon and the off-noise source spectrum SPNoff used in the calculation of the 1st to Nth observed noises (i: 1 to N) in the above may differ depending on the load current X(i).

[0247] As described above, according to the noise analysis technique of the fourth embodiment, the load current dependency of the noise intensity from the noise source (semiconductor element) can be considered, and thus the noise analysis can be performed with higher accuracy.

[0248] In addition, embodiments 2 to 4 can be combined with the embodiment 1 described as a modified example. Fig.13 , Fig.14 , Fig.21 And other combinations.

[0249] (Noise analysis device and noise analysis method for calculating observed noise using noise source as noise observation point)

[0250] In Embodiments 1 to 4, an example of a noise analysis device is described in which an observed noise calculation result RTNS including multiplication with a noise transfer function (Gon, Goff, Gcmn) is calculated as a total spectrum of noise generated by the switching of a semiconductor switching element. However, it is generally understood that in order to reflect the behavior of changes in the on-period length and off-period length of a semiconductor element in a PWM waveform, etc., a transient waveform including a plurality of switching cycles of a plurality of on and off is Fourier transformed to perform noise analysis, so that the time width of the object of Fourier transform increases. When considering this technical issue, in Embodiments 1 to 4, even if a structure is adopted in which an observed noise calculation result RTNS not including multiplication with a noise transfer function is calculated as the above-mentioned total spectrum, the above-mentioned technical issue can be solved. The observed noise not including multiplication with a noise transfer function is equivalent to the observed noise with a noise source as a noise observation point. In this case, the observed noise calculation result RTNS similar to Embodiments 1 to 4 can be obtained by multiplying the calculated observed noise calculation result RTNS by the noise transfer function (Gon, Goff, Gcmn).

[0251] Therefore, the noise analysis device of the above-mentioned embodiments 1 to 4 can achieve the above-mentioned effect even if it operates in a manner of calculating the observed noise by using the noise source as the noise observation point while excluding the multiplication element with the noise transfer function. Fig.35 , Figures 39 to 42 The functions of the blocks included in the noise analysis function unit 1Y are realized by calculation processing performed by the information processing device 51, thereby executing a noise analysis device or a noise analysis method for calculating the observed noise using the noise source as a noise observation point.

[0252] Fig.35 This is a block diagram for explaining a first configuration example of a noise analysis device for calculating observation noise using a noise source as a noise observation point according to the present embodiment.

[0253] Reference Fig.35 In the first structural example, the noise analysis function unit 1Y of this embodiment has Figure 2 The noise analysis function unit 1 shown in FIG. 1 is a structure in which the noise transfer function acquisition unit 4 is removed. Fig.36 As shown, Fig.35 The observation noise calculation unit 10 is configured to include a total calculation unit 10Z instead of Fig.10 and Fig.11 Total calculation unit 10X.

[0254] Fig.37 Show Fig.36 The structure of the total calculation unit 10Z is shown.

[0255] like Fig.37 As shown, the total calculation unit 10Z and Fig.11 The difference from the total calculation unit 10X shown in FIG. 1 is that the multiplication units 12 and 13 and the addition unit 17 for multiplying the noise transfer functions Gon and Goff from the noise transfer function acquisition unit 4 are omitted.

[0256] As a result, in Fig.37 In the process, instead of multiplying the on-noise source spectrum SPNon and the off-noise source spectrum SPNoff reflecting the phase difference information by the noise transfer functions Gon and Goff, each of the i-th on-observation noise NSon(i) and the i-th off-observation noise NSoff(i) is calculated as "multiple noise spectra obtained by phase transformation".

[0257] exist Fig.37 In the example, the adding unit 18 calculates the added values ​​ΣNSon(i) of NSon(1) to NSon(N) from the first to the Nth time and the added values ​​ΣNSoff(i) of NSoff(1) to NSoff(N) from the first to the Nth time. As a result, Fig.37 In the total calculation unit 10Z, ΣNSon(i) of the on-noise source spectrum and ΣNSoff(i) of the off-noise source spectrum are calculated as the observed noise calculation result RTNS with the noise source as the noise observation point. In this case, ΣNSon(i) and ΣNSoff(i) are equivalent to the total spectrum obtained by adding a plurality of noise spectra obtained by phase transformation. In contrast, it is generally understood that in embodiments 1 to 4, the total spectrum obtained by adding a plurality of noise spectra after multiplying the noise transfer function and performing phase transformation is calculated as the observed noise calculation result RTNS. Fig.37 As shown by the arrows with diagonal lines in , at the input of the adder 18 , the turned-on NSon(1) to NSon(N) and the turned-off NSoff(1) to NSoff(N) are processed separately, and as a result, ΣNSon(i) and ΣNSoff(i) are outputted separately from the adder 18 .

[0258] In addition, for Fig.37 The total calculation unit 10Z can also be used in the application Fig.34 A variation of the phase transformation in the time domain of the structure of Fig.37 In the structure of , the phase conversion units 14a, 14b and the multiplication units 15, 16 are deleted, and the phase conversion units 14a, 14b and the multiplication units 15, 16 are replaced by Fig.34The on-state observation noise N Son(i) after Fourier transform by the Fourier transform unit 23 for N times and the off-state observation noise NSoff(i) after Fourier transform by the Fourier transform unit 24 for N times are input to the adding unit 18, so that the same ΣNSon(i) and ΣNSoff(i) can be calculated as the observation noise calculation result RTNS with the noise source as the noise observation point.

[0259] Similarly, regarding the use of the noise transfer function Gcmn set commonly for both the on and off times Fig.13 The structure is also achieved through Fig.38 Removing the multiplication with the noise transfer function as shown enables the device to operate as a noise analysis device that calculates the observed noise using the noise source as a noise observation point.

[0260] Reference Fig.38 , Fig.35 The observation noise calculation unit 10 can be configured as follows: Fig.13 The multiplication unit 12Y is deleted from the structure, and a total calculation unit 10Y' is further provided instead of the total calculation unit 10Y.

[0261] The total calculation unit 10Y' can be configured as follows: Fig.37 In the total calculation unit 10Z, the addition unit 18 performs the addition operation of NSon(1) to NSon(N) from the first to the Nth time and the addition operation of NSoff(1) to NSoff(N) from the first to the Nth time, and then sets Fig.11 The same adding unit 17 performs addition operation of the on-noise and the off-noise. Fig.37 ΣNS(i), which is equivalent to the sum of ΣNSon(i) and ΣNSoff(i), is the observed noise calculation result RTNS with the noise source as the noise observation point. In this case, ΣNS(i) is equivalent to the total spectrum obtained by adding a plurality of noise spectra after phase transformation.

[0262] In this case, even if the order of addition by the adder 17 and the adder 18 is changed, the same observed noise calculation result RTNS can be calculated. That is, even if a configuration is adopted in which the addition unit 17 calculates N times "NSon(i)+NSoff(i)" for the addition of the on-noise and the off-noise and then the addition unit 18 calculates the sum of "NSon(1)+NSoff(1)" to "NSon(N)+NSoff(N)", the same ΣNS(i) as above can be calculated as the observed noise calculation result RTNS.

[0263] exist Fig.38 You can also use the application Fig.34Specifically, the phase conversion units 14a, 14b and the multiplication units 15, 16 are deleted, and the phase conversion units 14a, 14b and the multiplication units 15, 16 are deleted. Fig.38 In the structure of Fig.34 The on-state observation noise N Son(i) after Fourier transform by the Fourier transform unit 23 and the off-state observation noise NSoff(i) after Fourier transform by the Fourier transform unit 24 can be calculated as the observation noise calculation result RTNS with the noise source as the noise observation point.

[0264] As described above, the observed noise calculation result RTNS (i.e., the total spectrum excluding the multiplication with the noise transfer function) obtained by the noise analysis function unit 1Y of this embodiment can be obtained by, for example, multiplying the noise transfer function (Gon, Goff, Gcmn) outside the noise analysis device, and thus the observed noise calculation result RTNS similar to that of Embodiments 1 to 4 can be obtained. Figure 35~Figure 42 The noise analysis device for calculating the observed noise using the noise source as the noise observation point described above and the noise transfer function acquisition unit 4 and the multiplication elements (multiplication units 12 , 13 , 12Y) in Embodiments 1 to 4 constitute the same noise analysis device as Embodiments 1 to 4.

[0265] In this way, even if the noise analysis device of the present embodiment is configured to calculate the observed noise with the noise source as the noise observation point, it is possible to output a total spectrum reflecting the behavior of the phase change due to the change in the on-period length and the off-period length as the observed noise calculation result RTNS. In this case, it is possible to suppress the increase in the time required for Fourier transformation caused by the increase in the time width as the object of Fourier transformation, thereby achieving high-speed noise analysis.

[0266] exist Fig.39 In the second configuration example of the noise analysis device for calculating the observed noise using the noise source as the noise observation point, the noise analysis function unit 1Y has Fig.14 The noise analysis function unit 1 shown in the figure is a structure in which the noise transfer function acquisition unit 4 is removed. As a result, the observation noise calculation unit 10 can calculate the total value (total spectrum) of a plurality of noise spectra after phase transformation without multiplication with the noise transfer function (Gon, Goff, Gcmn) as the observation noise calculation result RTNS.

[0267] Likewise, if Figure 40~Figure 42 As shown, based on the configuration of the noise analysis device of Embodiments 2 to 4, a noise analysis device that calculates the observed noise using the noise source as the noise observation point can be configured.

[0268] In a noise analysis device ( Fig.40 ) in the third structural example, the noise analysis function unit 1Y has Fig.26 The noise analysis function unit 1 shown in (Embodiment 2) is configured by removing the noise transfer function acquisition unit 4. This makes it possible to calculate an observation noise calculation result RTNS equivalent to a total spectrum obtained by adding a plurality of noise spectra after phase conversion without multiplication with the noise transfer function (Gon, Goff, Gcmn).

[0269] In addition, in a fourth configuration example ( Fig.41 ), the noise analysis function unit 1Y has Fig.28 The noise transfer function acquisition unit 4 is removed from the noise analysis function unit 1 shown in (Embodiment 3). Fig.35 , Fig.39 and Fig.40 Similarly, an observation noise calculation result RTNS corresponding to a total spectrum obtained by adding a plurality of noise spectra after phase conversion excluding multiplication with the noise transfer function (Gon, Goff, Gcmn) can be calculated.

[0270] Similarly, in the fifth configuration example ( Fig.42 ), the noise analysis function unit 1Y has Fig.31 The noise transfer function acquisition unit 4 is removed from the noise analysis function unit 1 shown in Embodiment 4. Fig.35 and Figure 39~Figure 41 Similarly, an observation noise calculation result RTNS equivalent to a total spectrum obtained by adding a plurality of noise spectra after phase conversion without multiplication with the noise transfer function (Gon, Goff, Gcmn) can be calculated. Figure 39~Figure 42 In each of the figures, the observation noise calculation unit 10 can be Figure 36~Figure 38 The structure described in is constructed in the same manner.

[0271] As described above, each of the embodiments 1 to 4 also discloses the use of Figure 35~Figure 42A noise analysis device for calculating observed noise using a noise source as a noise observation point is described. When the noise source is used as the noise observation point, the noise analysis device can also suppress the increase in the time required for Fourier transformation caused by the increase in the time width of the object of Fourier transformation, and can output a total noise spectrum reflecting the behavior of the phase changing due to the change in the length of the on period and the length of the off period as the observed noise calculation result RTNS. As a result, the following noise analysis technology can be provided, which can prevent the time of noise analysis from becoming longer and can quickly and accurately derive the final calculation result of the observed noise.

[0272] In addition, it is confirmed that the following is recorded: for the multiple embodiments described above, including combinations not mentioned in the specification, it was planned from the beginning of the application that the structures described in each embodiment can be combined as appropriate within the scope that no incompatibility or contradiction occurs.

[0273] In addition, in the above embodiment, a configuration example of analyzing noise from both a turn-on noise source and a turn-off noise source, that is, a noise analysis technique for calculating observed noise related to noise generated by "switching" including turning on and off of a semiconductor element is described. That is, in this embodiment, an example of performing the noise analysis of the present disclosure using both the turn-on time ton(i) and the turn-off time toff(i) as "multiple occurrence times" is described.

[0274] On the other hand, it is also possible to mainly observe either the noise caused by turning on or the noise caused by turning off the semiconductor element. In this case, noise analysis can be performed without considering the noise source of the non-main party.

[0275] For example, in the case where the noise at the time of switching on is dominant, the observed noise calculation result RTNS can be calculated without considering the disconnection noise source, that is, by deleting the NSoff item. In this case, the structure for obtaining the disconnection transient waveform or the disconnection noise source spectrum can be deleted from the noise analysis function unit 1. In this way, the noise analysis technology (noise analysis technology and noise analysis method) of the present embodiment can be applied to the calculation of the observed noise related to the noise generated by the "opening and closing" of at least one of the switching on and off of the semiconductor element. In this case, only one of the switching on time ton (i) and the switching off time toff (i) is set as the "multiple occurrence times" to perform the noise analysis of the present disclosure.

[0276] In addition, although Figure 1 , a configuration example of realizing a noise analysis device by executing a program (noise analysis program) for executing the noise analysis technique of this embodiment by the information processing device 51 is described, but the noise analysis program may also be implemented in Figure 1Alternatively, the execution of the noise analysis program that works as a noise analysis device may be shared among a plurality of devices. That is, the noise analysis program may be shared by part or all of the information processing devices 51 and 53 and the cloud 54 to form a noise analysis device.

[0277] In addition, the data of the on-transient waveform and the off-transient waveform (in the time domain or the frequency domain), the data of the on-off control signal, and the data of the noise transfer function may be stored in any of the information processing devices 51, 53, and the cloud 54. Similarly, the storage location of the observation noise calculation result RTNS is not limited to the information processing device 51, but may be the information processing device 53 and / or the cloud 54.

[0278] Similarly, the display location of the observed noise calculation result RTNS is not limited to the information display device 52, but can be any of the information display device of the information processing device 53 and the virtual information display environment of the cloud 54. For example, the content of the virtual information display environment can be displayed on the information display device 52 by accessing the cloud 54 through the information processing device 51.

[0279] In this way, by sharing the processing of the noise analysis technology of the present embodiment among a plurality of execution entities, noise analysis can be easily performed even if the data storage performance or processing performance of the information processing device 51 is not high. In particular, by utilizing the cloud 54, the noise analysis technology (noise analysis program) that can derive noise quickly and accurately even when the on-period length and the off-period length of the semiconductor element vary can be easily provided to a large number of users as a noise analysis service via the network.

[0280] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A noise analysis device for calculating a total spectrum of noise generated by at least one of switching on and off of a semiconductor element, the noise analysis device comprising: A first acquisition unit that acquires information indicating a plurality of occurrence times at which the plurality of switching operations of the semiconductor element respectively occurred during a noise analysis target period including the plurality of switching operations of the semiconductor element; a phase conversion unit that generates a plurality of phase difference information corresponding to the plurality of occurrence times acquired by the first acquisition unit, the plurality of phase difference information being used to perform phase conversion reflecting time differences of the plurality of openings and closings on a noise spectrum of the semiconductor element during the opening and closing; and The first adding unit is configured to calculate the total spectrum obtained by adding a plurality of noise spectra obtained by phase-shifting the noise spectra of the semiconductor element when the semiconductor element is switched on and off using the plurality of phase difference information.

2. The noise analysis device according to claim 1, wherein: The noise spectrum of the semiconductor element when it is switched on and off is a noise source spectrum obtained by Fourier transforming transient waveform data of the semiconductor element when it is switched on and off.

3. The noise analysis device according to claim 1, further comprising: a second acquisition unit that acquires a noise transfer function of a propagation path between the semiconductor element and a noise observation point; and a first multiplication unit for calculating a multiplication value of a noise source spectrum obtained by Fourier transforming transient waveform data of the semiconductor element during the switching operation and the noise transfer function; The noise spectrum of the semiconductor element during the switching is the multiplication value.

4. The noise analysis device according to claim 3, wherein: The second acquisition unit acquires a plurality of transfer functions for each of a plurality of propagation paths divided between the semiconductor element and the noise observation point, The noise analysis device further includes a transfer function integration unit that integrates the plurality of transfer functions acquired by the second acquisition unit to output the noise transfer function.

5. The noise analysis device according to any one of claims 2 to 4, further comprising: The third acquisition unit acquires the noise source spectrum that has been subjected to Fourier transformation.

6. The noise analysis device according to any one of claims 2 to 4, further comprising: A third acquisition unit, which acquires the transient waveform data; and The Fourier transform unit generates the noise source spectrum by performing Fourier transform on the transient waveform data acquired by the third acquisition unit.

7. The noise analysis device according to claim 6, wherein: The plurality of occurrence times are individually set corresponding to the connection and the disconnection, respectively. The third acquisition unit acquires the transient waveform data including the transient waveforms of one or more turning-on and one or more turning-off of the semiconductor element. The noise analysis device further includes a data separation unit that extracts separately the transient waveform data at the time of the ON state and the transient waveform data at the time of the OFF state from the transient waveform data acquired by the third acquisition unit. The Fourier transform unit separately outputs the noise source spectrum obtained by Fourier transforming the transient waveform data at the time of on and the noise source spectrum obtained by Fourier transforming the transient waveform data at the time of off.

8. The noise analysis device according to any one of claims 2 to 6, wherein: The noise source spectrum and the plurality of occurrence times are individually set corresponding to the on and off, respectively.

9. The noise analysis device according to any one of claims 2 to 8, further comprising: a fifth acquisition unit that acquires information on a load current flowing through the semiconductor element during the noise analysis target period; and The noise source spectrum correction unit corrects the magnitude of the noise source spectrum according to the load current at each of the plurality of occurrence times.

10. The noise analysis device according to any one of claims 1 to 9, further comprising: A fourth acquisition unit, which acquires information related to the resolution bandwidth; A window function setting unit, which sets a window function in a shape reflecting the resolution bandwidth; a weighting coefficient setting unit that outputs the values ​​of the window function of each of the plurality of occurrence times acquired by the first acquisition unit as a plurality of weighting coefficients corresponding to the plurality of occurrence times, respectively; as well as a second multiplication unit, configured to calculate a plurality of multiplication values ​​obtained by multiplying the plurality of noise spectra by the plurality of weighting coefficients respectively; The first adding unit calculates a calculation result of the total spectrum by adding the plurality of multiplication values ​​obtained by the second multiplying unit.

11. The noise analysis device according to any one of claims 1 to 10, wherein: calculating the total spectrum related to the noise generated by the switching of the plurality of semiconductor elements, The device further includes a second adding unit for calculating a calculation result of the total spectrum of the plurality of semiconductor elements by adding together the calculation results of the total spectrum of the respective semiconductor elements.

12. The noise analysis device according to any one of claims 1 to 11, characterized in that: A plurality of the noise analysis target periods are set, and statistical calculation results of a plurality of the total spectrums corresponding to the plurality of set noise analysis target periods are output.

13. A noise analysis method, comprising calculating a total spectrum of noise generated by switching on and off of a semiconductor element, wherein: acquiring information indicating a plurality of occurrence times at which the plurality of switching operations of the semiconductor element respectively occurred during a noise analysis target period including the plurality of switching operations of the semiconductor element; generating a plurality of phase difference information corresponding to the plurality of occurrence times, respectively, the plurality of phase difference information being used to perform a phase transformation reflecting the time difference of the plurality of switchings on a noise spectrum of the semiconductor element during the switching, The total spectrum is calculated by adding a plurality of noise spectra obtained by phase-shifting the noise spectra of the semiconductor element when the semiconductor element is switched on and off using the plurality of phase difference information.

14. The noise analysis method according to claim 13, wherein: The noise spectrum of the semiconductor element when it is switched on and off is a noise source spectrum obtained by Fourier transforming transient waveform data of the semiconductor element when it is switched on and off.

15. The noise analysis method according to claim 13, wherein: In the noise analysis method, obtaining a noise transfer function of a propagation path between the semiconductor element and a noise observation point, calculating a multiplication value of a noise source spectrum obtained by Fourier transforming transient waveform data of the semiconductor element during the switching and the noise transfer function, The noise spectrum of the semiconductor element during the switching is the multiplication value.

16. The noise analysis method according to claim 15, wherein: In the noise analysis method, acquiring a plurality of transfer functions for each of a plurality of propagation paths divided between the semiconductor element and the noise observation point, The multiplication value is calculated using the noise transfer function obtained by integrating the plurality of acquired transfer functions.

17. The noise analysis method according to any one of claims 14 to 16, wherein: In the noise analysis method, Obtain the noise source spectrum that has been Fourier transformed, The multiplication value is calculated using the acquired noise source spectrum.

18. The noise analysis method according to any one of claims 14 to 16, wherein: In the noise analysis method, Acquiring the transient waveform data and performing Fourier transform on the acquired transient waveform data to generate the noise source spectrum, The multiplication value is calculated using the generated noise source spectrum.

19. The noise analysis method according to any one of claims 14 to 18, wherein: The noise source spectrum and the plurality of occurrence times are individually set corresponding to the on and off, respectively.

20. The noise analysis method according to any one of claims 14 to 19, wherein: In the noise analysis method, acquiring information on a load current flowing through the semiconductor element during the noise analysis target period, The magnitude of the noise source spectrum is corrected according to the load current at each of the plurality of occurrence times.

21. The noise analysis method according to any one of claims 13 to 20, wherein: In the noise analysis method, Get information about the resolution bandwidth, The window function is set to reflect the shape of the resolution bandwidth, The values ​​of the window functions of the plurality of occurrence times acquired are set as a plurality of weighting coefficients respectively corresponding to the plurality of occurrence times, calculating a plurality of multiplication values ​​obtained by multiplying the plurality of noise spectra by the plurality of weighting coefficients respectively, The calculation result of the total spectrum is calculated by adding the plurality of multiplication values ​​obtained by multiplying the plurality of weighting coefficients.

22. The noise analysis method according to any one of claims 13 to 21, wherein: When calculating the total spectrum related to noise generated by the switching of the plurality of semiconductor elements, calculation results of the total spectrum for each of the semiconductor elements are totaled to calculate a calculation result of the total spectrum for the plurality of semiconductor elements.

23. The noise analysis method according to any one of claims 13 to 22, wherein: A plurality of the noise analysis target periods are set, and statistical calculation results of a plurality of the total spectrums corresponding to the plurality of set noise analysis target periods are calculated.

24. A program for causing a computer to execute the method according to any one of claims 13 to 23.

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