Power supplies, power supply units, test equipment

Abstract

To provide a high voltage power supply with an improved settling operation.SOLUTION: A power supply device 100 includes stacking-connected multi-channel power supply unit 200. Each power supply unit 200 includes an output stage 210 that generates an output voltage Vi according to a control signal Vctrl between a positive electrode output OUTP and a negative electrode output OUTN. A current detector 250 of a master channel generates a current detection signal Is indicating an output current of the output stage 210. A feedback controller 240 generates a control signal Vctrl such that the current detection signal Is approaches a target value Iref.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a power supply apparatus that supplies a power supply voltage or a power supply current to a device. [Background technology]

[0002] In recent years, research and development of power devices such as SiC (silicon carbide) FETs (field-effect transistors) and GaN (gallium nitride) HEMTs (high electron mobility transistors), which enable highly efficient power conversion by switching high voltages at high speeds, has become active for the purpose of energy conservation. Accordingly, the demand for device testing that applies high voltages has also increased, and there is a strong demand for shortening the test time. In such device testing, it is necessary to apply high-voltage and highly accurate DC voltages of 1000V, and in some devices, 2000V.

[0003] When the maximum output voltage of a power supply device for a test device is not sufficient to supply a high voltage to a load, it is necessary to connect power supplies (hereinafter referred to as power supply units) of multiple channels in series (hereinafter referred to as stack connection). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-138557 A [Patent Document 2] Special Publication No. 2013-535949 Summary of the Invention [Problem to be solved by the invention]

[0005] Fig. 1 is a block diagram of a high-voltage power supply 100R. Referring to Fig. 1, the high-voltage power supply 100R includes power supply units 110_1 to 110_N of multiple channels CH1 to CHN that are stacked together. The power supply unit 110 of each channel has a primary side P and a secondary side S, and the primary side P and the secondary side S are insulated via an isolation barrier 112 such as a transformer or a capacitor. The ground terminals GND of the primary sides P of the multiple power supply units 110_1 to 110_N are commonly connected.

[0006] A positive output OUTP and a negative output OUTN are provided on the secondary side S of the power supply unit 110, and an output stage 120 is provided between the positive output OUTP and the negative output OUTN.

[0007] Generally, a power supply device can switch between a voltage application mode (constant voltage mode) in which a constant voltage is supplied to a load and a current application mode (constant current mode) in which a constant current is supplied to a load. Consider a case in which a high-voltage power supply 100R in which multiple power supply units 110 are stacked, as shown in Fig. 1, is operated in a current application mode. For ease of explanation, it is assumed here that N=2 stages of power supply units 110_1, 110_2 are stacked.

[0008] (Comparative Technology 1) In the comparative technique 1, all the stacked power supply units 110_1 and 110_2 are operated in a current application mode with the same target value (set value) Iref. In this case, the same current Iref flows through all the channels, and ideally the same current amount is detected in all the channels. However, in reality, due to detection errors, the current Iref+ΔI deviates from the target value Iref in each of the power supply units 110_1 and 110_2. 1 , Iref+ΔI 2 In this case, the current I supplied from the high voltage power supply 100R to the load can be detected. OUT teeth, I OUT =Iref-(ΔI 1 +ΔI 2 ) / 2 In other words, the output current I OUTis the detection error ΔI 1 ,ΔI 2 The current is calculated by subtracting the average value of

[0009] 2(a) is a diagram showing a voltage waveform at the start-up of the high-voltage power supply according to the comparative technique 1. 1 ,ΔI 2 As a result, the state of the power supply unit for each channel will converge to one of the following states: (1) The output voltage decreases and reaches the lower limit of the usable voltage (called the minimum usable voltage). (2) The output voltage rises and reaches the upper limit of the usable voltage (called the upper limit voltage). In Figure 2(a), the voltage V 1 drops to the lower limit of the voltage range, and the voltage V 2 has risen to the upper limit of operating voltage.

[0010] In other words, even if two power supply units are stacked to generate a high voltage, some channels will operate at the lower limit voltage, and as a result, the desired high voltage cannot be generated. In other words, comparative technology 1 cannot be adopted in reality.

[0011] (Comparative Technology 2) In the comparative technique 2, one of the power supply units 110 is operated in a current application mode, and the rest are operated in a voltage application mode. Here, the power supply unit 110_1 is operated in a current application mode, and the power supply unit 110_2 is operated in a voltage application mode. The voltage setting value (target value) Vref of the power supply unit 110_2 in the voltage application mode is set to a value equal to the expected load voltage V OUTH The following provisions should be made appropriately, taking into consideration the above points:

[0012] 2B is a diagram showing a voltage waveform at the start of the high-voltage power supply according to the comparative technique 2. First, the power supply unit 110_2 in the voltage application mode starts up first, and the output voltage V 2 After the voltage reaches the voltage setting value Vref, the power supply unit 110_1 in the current application mode starts applying current.

[0013] In comparative technique 2, the voltage setting value Vref of the channel operated in voltage application mode needs to be set according to the load. For example, a high voltage setting value Vref needs to be set for a high voltage load, but if the load is changed to another one with a low withstand voltage, a problem may occur in which an overvoltage is applied to the load. In other words, the method of comparative technique 2 lacks versatility.

[0014] In addition, since it is necessary to operate the voltage application and current application channels in sequence, settling occurs in two stages, making it impossible to obtain the same startup waveform as in the case of a single channel, and the settling time becomes longer.

[0015] One aspect of the present disclosure has been made in this context, and one of its exemplary purposes is to provide a high-voltage power supply with improved settling behavior. [Means for solving the problem]

[0016] One aspect of the present disclosure is a power supply device. The power supply device includes power supply units of multiple channels that are stacked. Each of the power supply units of the multiple channels includes a positive output and a negative output, and an output stage that generates an output voltage between the positive output and the negative output in response to a control signal. The power supply unit of a master channel, which is one of the multiple channels, further includes a current detector that generates a current detection signal that indicates an output current of the output stage, and a feedback controller that generates a control signal so that the current detection signal approaches a target value. The output stages of all the channels operate based on the control signal generated by the feedback controller of the master channel.

[0017] Another aspect of the present disclosure is a power supply unit. A power supply device can be configured by stacking a plurality of such power supply units. The power supply unit includes a positive output and a negative output, an output stage that generates an output voltage between the positive output and the negative output in response to a control signal, a current detector that is active when set to the master channel and generates a current detection signal indicating an output current of the output stage, a feedback controller that is active when set to the master channel and generates a control signal so that the current detection signal approaches a target value, and an interface circuit that transmits a control signal to other channels when set to the master channel and receives a control signal from the master channel when set to the slave channel.

[0018] Any combination of the above components, or mutual substitution of the components or expressions of the present invention between methods, devices, systems, etc. are also valid aspects of the present invention. Effect of the Invention

[0019] According to certain aspects of the present disclosure, the settling operation can be improved when the number of stack stages is large. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a block diagram of a high voltage power supply. [Diagram 2] FIG. 2(a) is a diagram showing a voltage waveform at the start-up of a high-voltage power supply according to Comparative Technique 1, and FIG. 2(b) is a diagram showing a voltage waveform at the start-up of a high-voltage power supply according to Comparative Technique 2. [Diagram 3] 1 is a block diagram showing a test device including a power supply device according to an embodiment; [Figure 4] 4 is a diagram showing voltage waveforms and current waveforms at the time of start-up of the power supply device of FIG. 3. [Diagram 5] 1 is a block diagram of a power supply device according to a first embodiment. [Figure 6] FIG. 11 is a block diagram of a power supply device according to a second embodiment. [Figure 7]FIG. 11 is a block diagram of a power supply unit according to a third embodiment. [Figure 8] 8(a) and (b) are diagrams showing the states of the power supply unit of FIG. 7 in the master mode and the slave mode. [Figure 9] FIG. 2 is a block diagram showing a specific configuration example of a power supply unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] (Overview of the embodiment) A summary of some exemplary embodiments of the present disclosure will be described. This summary is intended to provide a simplified summary of some concepts of one or more embodiments in order to provide a basic understanding of the embodiments as a prelude to the detailed description that follows, and is not intended to limit the scope of the invention or disclosure. Furthermore, this summary is not intended to be a comprehensive overview of all possible embodiments, nor is it intended to limit essential components of the embodiments. For convenience, the term "one embodiment" may be used to refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed in this specification.

[0022] A power supply device according to one embodiment includes power supply units of multiple channels connected in a stack. Each of the power supply units of the multiple channels includes a positive output and a negative output, and an output stage between the positive output and the negative output that generates an output voltage according to a control signal. The power supply unit of a master channel, which is one of the multiple channels, further includes a current detector that generates a current detection signal indicating an output current of the output stage, and a feedback controller that generates a control signal so that the current detection signal approaches a target value. The output stages of all the channels operate based on the control signal generated by the feedback controller of the master channel.

[0023] With this configuration, current measurement is performed only in the master channel, which is one of the multiple channels, and feedback control for current application is performed.The control signal obtained in the master channel is then sent to the other slave channels, thereby realizing the same operation as a single-channel power supply device and improving the settling operation.

[0024] In one embodiment, each of the power supply units of the multiple channels may further include a voltage detector that generates a voltage detection signal indicating an output voltage of the output stage. The power supply unit of the master channel may further include a voltage feedback signal generator that receives voltage detection signals from the power supply units of the slave channels, which are the remaining channels, and generates a voltage feedback signal based on the voltage detection signals of all the channels. When the voltage feedback signal exceeds a predetermined limit value, the feedback controller of the master channel may generate a control signal so that the voltage feedback signal approaches the limit value. This makes it possible to realize a voltage clamp operation so that the total voltage of all the channels does not exceed a predetermined upper limit.

[0025] The voltage feedback signal may be the average value of the voltage sense signals of all channels.

[0026] In one embodiment, the power supply unit of the master channel may further include a voltage detector that generates a voltage detection signal indicating the output voltage of the output stage. When the voltage detection signal exceeds a predetermined limit value, the feedback controller may generate a control signal so that the voltage detection signal approaches the limit value. In this case, the voltage clamp operation of all channels can be realized based on the state of the master channel.

[0027] In one embodiment, the power supply units for multiple channels may be configured similarly, including a feedback controller and a current detector. Each power supply unit may be selectable between a master mode and a slave mode, and when set to the master mode, the feedback controller may be enabled, and when set to the slave mode, the feedback controller may be disabled. Note that "disabling a certain circuit block" may include not only not operating the block, but also operating the block but not using it by blocking or masking its output.

[0028] By preparing multiple identical power supply units, rearranging the connections, and setting the mode appropriately, it is possible to change the number of loads. For example, if there are N power supply units, you can stack them and set one of them in master mode and the rest in slave mode to supply power to one load. Alternatively, you can use all N units independently in master mode to supply power to N loads.

[0029] The master channel may be located at the top of the multiple channels.

[0030] A power supply device can be configured by stacking a plurality of power supply units according to an embodiment. The power supply unit includes a positive output and a negative output, an output stage that generates an output voltage between the positive output and the negative output in response to a control signal, a current detector that is active when set to the master channel and generates a current detection signal indicating an output current of the output stage, a feedback controller that is active when set to the master channel and generates a control signal so that the current detection signal approaches a target value, and an interface circuit that transmits a control signal to other channels when set to the master channel and receives a control signal from the master channel when set to the slave channel.

[0031] According to this configuration, when multiple channels are stacked, current measurement is performed only in the master channel, and feedback control for current application is performed. Then, by transmitting the control signal obtained in the master channel to the other slave channels, the same operation as a single-channel power supply device can be realized, and the settling operation can be improved. In addition, by preparing multiple identical power supply units, rearranging the connections, and appropriately setting the mode, it is possible to change the number of loads.

[0032] In one embodiment, the output stage may further include a voltage detector that generates a voltage detection signal indicative of an output voltage of the output stage. When set to the master channel, the feedback controller may generate a control signal when the voltage detection signal exceeds a predetermined limit value so that the voltage detection signal approaches the limit value.

[0033] In one embodiment, a plurality of power supply units may be connected in a stack.

[0034] (Embodiment) The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the embodiments are illustrative rather than limiting the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0035] In this specification, "a state in which component A is connected to component B" includes not only a case in which component A and component B are directly physically connected to each other, but also a case in which component A and component B are indirectly connected to each other via other components that do not substantially affect the electrical connection state between them or that do not impair the function or effect achieved by their combination.

[0036] Similarly, "a state in which component C is provided between components A and B" includes not only the case in which components A and C, or components B and C, are directly connected to each other, but also the case in which they are indirectly connected to each other via other components that do not substantially affect the electrical connection between them or that do not impair the functions or effects achieved by their combination.

[0037] 3 is a block diagram showing a test apparatus 2 including a power supply device 100 according to an embodiment. The test apparatus 2 applies test signals such as voltage signals and current signals to a DUT (device under test) 1, and measures the response of the DUT 1. There is no particular limitation on the type of DUT 1, but devices that require application of a high voltage exceeding 1000V, such as high-voltage power transistors and power modules, or circuits or circuit systems including such devices, are suitable as test subjects for this test apparatus 2.

[0038] The test apparatus 2 includes a power supply apparatus 100 that supplies a power supply signal to the DUT 1. In this embodiment, the power supply signal is a current signal I stabilized to a predetermined current amount (target amount). OUT In addition, in FIG. 3, the current signal I OUT is supplied, but this is not the only case. OUT may be supplied to peripheral circuits of the DUT1, a circuit that drives the DUT1, and a circuit that interfaces with the DUT1.

[0039] In addition to the power supply device 100, the test apparatus 2 is equipped with a voltage sensor, a current sensor, a signal generator, a driver, a comparator, an A / D converter, a D / A converter, etc., but these depend on the type of DUT 1 and the test items, and are omitted in Figure 3.

[0040] The power supply device 100 includes power supply units 200_1 to 200_N of multiple N channels (CH1 to CHN) connected in a stack. Each power supply unit 200 has a positive output OUTP and a negative output OUTN. Like the power supply unit 110 in FIG. 1, the power supply unit 200 has an insulated primary side and secondary side, but FIG. 3 shows only the configuration of the secondary side. The negative output OUTN forms a reference potential (ground) for the secondary side.

[0041] The negative output OUTN of the power supply unit 110_i of the i-th (1≦i≦N-1) channel is connected to the positive output OUTP of the power supply unit 110_(i+1) of the (i+1)-th channel. The positive output OUTP of the power supply unit 110_1 of the 1st channel is connected to the load 1, and the negative output OUTN of the power supply unit 110 of the N-th channel is grounded.

[0042] Each of the power supply units 200 of the multiple channels includes an output stage 210. The output stage 210 of the i-th (i=1 to N) power supply unit 200_i outputs an output voltage V between a positive output OUTP and a negative output OUTN in response to a control signal Vctrl. i occurs.

[0043] In this embodiment, of the multiple N channels CH1 to CHN, one is set as a master channel and the rest are set as slave channels. Although not limited to this, in FIG. 3, the first channel CH1 is the master channel and the second to Nth channels CH2 to CHN are slave channels.

[0044] The power supply unit 200_1 of the master channel includes, in addition to the output stage 210, a current detector 250 and a feedback controller 240.

[0045] The current detector 250 detects the output current I OUT Current detection signal Is 1 This current detection signal Is 1 is input to the feedback controller 240 as a feedback signal Ifb.

[0046] The feedback controller 240 receives the output current I OUT The target value Iref of the feedback signal Ifb is input to the feedback controller 240. The feedback controller 240 feedback controls the signal level (magnitude) of the control signal Vctrl so that the feedback signal Ifb approaches the target value Iref. The control signal Vctrl generated by the feedback controller 240 is supplied to the output stage 210 of the master channel.

[0047] Signals can be transmitted and received between the master channel and the slave channel. Specifically, a control signal Vctrl can be transmitted from the power supply unit 200_1 of the master channel to the power supply units 200_2 to 200_N of the slave channels.

[0048] The output stages 210 of the slave channels CH2 to CHN operate based on a control signal Vctrl generated by the feedback controller 240 of the master channel CH1.

[0049] The power supply device 100 has the above configuration.

[0050] Fig. 4 is a diagram showing voltage waveforms and current waveforms at the time of start-up of the power supply device 100 in Fig. 3. Here, a configuration of N=2 channels will be described. For comparison, the waveforms of Comparative Technique 2 are shown by dashed lines.

[0051] As shown by the solid line, according to this embodiment, current measurement is performed only in the master channel, which is one of the multiple channels, and feedback control for current application is performed. Then, by transmitting the control signal Vctrl obtained in the master channel to the other slave channels, it is possible to realize the same operation as a single-channel power supply device and improve the settling operation compared to Comparative Technique 2.

[0052] The present disclosure covers various devices and methods that can be understood as the block diagram or circuit diagram of Fig. 3 or derived from the above description, and is not limited to a specific configuration. Below, more specific configuration examples and examples will be described in order to aid in understanding and clarify the essence and operation of the invention, not to narrow the scope of the present invention.

[0053] Example 1 5 is a block diagram of a power supply device 100 according to a first embodiment. This power supply device 100 has a voltage clamp function. Each of the power supply units 200_1 to 200_N of the multiple channels further includes a voltage detector 220. The voltage detector 220 of a certain channel CHi detects the output voltage V i Voltage detection signal Vs i The voltage detection signal Vs generated in the slave channels CH2 to CHN is generated. 2 ~Vs N is sent to the master channel.

[0054] The power supply unit 200_1 of the master channel CH1 includes a voltage feedback signal generating unit 230. The voltage feedback signal generating unit 230 receives a voltage detection signal Vs from the power supply units 200_2 to 200_N of the slave channels. 2 ~Vs N Receives the voltage detection signal Vs of all channels CH1 to CHN. 1 ~Vs N This voltage feedback signal Vfb is supplied to the feedback controller 240. For example, the voltage feedback signal Vfb is a simple average of the voltage detection signals of all channels, and is expressed by the following equation. Vfb=Σ i=1~N V i / N …(1)

[0055] When the voltage feedback signal Vfb is lower than a predetermined limit value Vlim, the feedback controller 240 of the master channel CH1 generates a control signal Vctrl so that the current feedback signal Ifb approaches the target value Iref (constant current control) as described above. On the other hand, when the voltage feedback signal Vfb exceeds the limit value Vlim, the constant current control is disabled, and the feedback controller 240 generates a control signal Vctrl so that the voltage feedback signal Vfb approaches the limit value Vlim (voltage clamp control).

[0056] In equation (1), Σ i=1~N V i is the generated voltage V for all channels CH1 to CHN 1 ~V N The sum of these voltages, i.e. the high voltage V supplied to the load OUTH Therefore, the voltage feedback signal Vfb in equation (1) is Vfb=V OUTH When the voltage clamp is enabled, the voltage feedback signal Vfb is equal to the limit value Vlim. Vfb=V OUTH / N=Vlim Therefore, the output voltage V of the power supply 100 OUTH can be clamped so as not to exceed Vlim×N.

[0057] When there is variation among the power supply units 200_1 to 200_N of the multiple channels, a weighted average may be calculated using a coefficient that takes the variation into consideration.

[0058] Example 2 6 is a block diagram of a power supply device 100 according to a second embodiment. This power supply device 100 has a voltage clamp function, similar to the first embodiment. A voltage detector 220 is provided in a power supply unit 200_1 of the master channel. A feedback controller 240 outputs a voltage detection signal Vs generated by the voltage detector 220. 1is lower than the predetermined limit value Vlim, the control signal Vctrl is generated so that the current feedback signal Ifb approaches the target value Iref (constant current control) as described above. 1 When the voltage detection signal Vs exceeds the limit value Vlim, the constant current control is disabled. 1 A control signal Vctrl is generated so that approaches the limit value Vlim (voltage clamp control).

[0059] When the gain variation of the output stage 210 of all the channels can be ignored, the output voltage V 1 ~V N is equal, so the output voltage V OUTH V 1 When the voltage clamp is enabled, the voltage V 1 Since is equal to the limit value Vlim, the output voltage V OUTH can be clamped so as not to exceed Vlim × N. The second embodiment may be adopted when such a high level of accuracy is not required for the voltage clamp control.

[0060] Example 3 The power supply unit 200_1 of the master channel and the power supply units 200_2 to 200_N of the slave channels may be designed as separate configurations from the beginning, or, as described below, may be configured as the same configuration and switchable between a mode when operating as a master channel and a mode when operating as a slave channel.

[0061] 7 is a block diagram of a power supply unit 200 according to a third embodiment. This power supply unit 200 can be used in both the master channel and the slave channel. The power supply unit 200 includes an output stage 210, a voltage detector 220, a voltage feedback signal generator 230, a feedback controller 240, a current detector 250, a mode selector 260, and a multiplexer (switch) 270.

[0062] Mode selector 260 generates a mode control signal MODE indicating the master mode when used in the master channel and the slave mode when used in the slave channel. The mode control signal MODE is input to enable terminals of voltage feedback signal generator 230, feedback controller 240, and current detector 250, and these blocks are enabled when the mode control signal MODE indicates the master mode and disabled when it indicates the slave mode.

[0063] An output of the feedback controller 240 in the same power supply unit 200 is connected to one input node of the multiplexer 270. A control signal Vctrl generated in another power supply unit 200 can be input to another input node of the multiplexer 270. When the mode control signal MODE indicates the master mode, the multiplexer 270 selects a control signal (internal control signal) Vctrl_int in the same power supply unit 200, and when the mode control signal MODE indicates the slave mode, the multiplexer 270 selects an external control signal Vctrl_ext generated in another power supply unit 200.

[0064] The power supply unit 200 also generates an internal control signal Vctrl_int and a voltage detection signal Vs i The power supply unit 200 can output the control signal Vctrl_ext and the voltage detection signal Vs i It is possible to receive.

[0065] Figures 8(a) and (b) are diagrams showing the states of the power supply unit 200 in Figure 7 in the master mode and the slave mode. In Figures 8(a) and (b), disabled blocks and signal lines are indicated by dashed lines.

[0066] 9 is a block diagram showing a specific example of the configuration of the power supply unit 200. The control system of this power supply unit 200 is implemented using a digital circuit architecture, and the detection signals and control signals are digital signals.

[0067] The output stage 210 includes a D / A converter 212 and a power amplifier 214. The output stage 210 converts the input digital control signal Vctrl into an analog control signal. The power amplifier 214 amplifies the analog control signal and outputs it to the positive output OUTP.

[0068] The voltage detector 220 includes a voltage sense amplifier 222 and an A / D converter 224. The voltage sense amplifier 222 detects the voltage V between the two outputs OUTPT and OUTN. i The A / D converter 224 amplifies the output of the sense amplifier 222 into a digital voltage detection signal Vs i Converts the voltage detection signal Vs i can be shared with other channels via an interface circuit 280.

[0069] The voltage feedback signal generating unit 230 includes an adder / subtractor 232 and a divider 234. The adder / subtractor 232 receives the voltage detection signal Vs of the same channel and the other channel. i The divider 234 divides the output of the adder / subtractor 232 by the number of channels N to generate a voltage feedback signal Vfb based on the average value. The divider 234 can also be understood as a coefficient circuit that multiplies the output of the adder / subtractor 232 by a coefficient 1 / N.

[0070] The current detector 250 includes a sense resistor 252, a sense amplifier 254, and an A / D converter 256. The sense resistor 252 detects the output current I OUT The sense resistor 252 is provided on the path of the output current I OUT A voltage drop proportional to the current is generated. The sense amplifier 254 amplifies the voltage drop across the sense resistor 252. The A / D converter 256 converts the output of the sense amplifier 254 into a digital current detection signal Is i The feedback controller 240 receives the target current value Iref and the voltage limit value Vlim as input.

[0071] The adder / subtractor 242 generates the difference (voltage error Verr) between the limit value Vlim and the voltage feedback signal Vfb. The adder / subtractor 246 generates the difference (current error Ierr) between the target value Iref and the current detection signal Is i (Ifb).

[0072] The selector 248 selects the current error Ierr (constant current control) when Vfb < Vlim, and selects the voltage error Verr (voltage clamp control) when Vfb > Vlim.

[0073] The filter 244 generates a control signal Vctrl based on the output of the selector 248. Although not limited thereto, the filter 244 can be composed of a PI (Proportional Integral) controller, a PID (Proportional Integral Derivative) controller, etc. In constant current control, the level of the control signal Vctrl is adjusted by feedback so that the current error Ierr approaches zero, and in voltage clamp control, the level of the control signal Vctrl is adjusted by feedback so that the voltage error Verr approaches zero. The parameters of the filter 244 may be switched between constant voltage control and current clamp control.

[0074] The feedback controller 240 and the voltage feedback signal generation unit 230 can be composed of a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), etc.

[0075] The interface circuit 280 can transmit and receive a voltage detection signal and a control signal Vctrl to and from the interface circuits 280 of other channels.

[0076] As described above, the present invention has been described based on the embodiments. These embodiments are illustrative, and various modifications may exist in each of these components, each processing process, and their combinations. Hereinafter, such modifications will be described.

[0077] In FIG. 9, the power supply unit 200 whose control system is implemented with a digital circuit architecture has been described, but this is not limiting, and the control system may be configured with an analog circuit.

[0078] The present invention has been described based on the embodiments, but the embodiments merely illustrate the principles and applications of the present invention, and many modifications and changes in arrangement are permitted to the embodiments without departing from the spirit of the present invention as defined in the claims. [Explanation of symbols]

[0079] 1...DUT, 2...test equipment, 100...power supply device, 200...power supply unit, 210...output stage, 220...voltage detector, 230...voltage feedback signal generator, 240...feedback controller, 250...current detector, 260...mode selector, 270...multiplexer, 280...interface circuit.

Claims

1. Equipped with a multi-channel power supply unit that is stacked, Each of the multiple channel power supply units comprises: a positive output and a negative output; an output stage that generates an output voltage between the positive output and the negative output in response to a control signal; Equipped with The power supply unit of the master channel, which is one of the multiple channels, a current detector for generating a current detection signal indicative of an output current of the output stage; a feedback controller that generates the control signal so that the current detection signal approaches a target value; Further equipped with A power supply device, characterized in that the output stages of the multiple channels operate based only on the control signal generated by the feedback controller of the master channel.

2. Each of the power supply units for the multiple channels further includes a voltage detector that generates a voltage detection signal indicative of an output voltage of the output stage; the power supply unit of the master channel further includes a voltage feedback signal generating unit that receives the voltage detection signals from the power supply units of the slave channels that are the remaining channels of the plurality of channels, and generates a voltage feedback signal based on the voltage detection signals of all the channels; 2. The power supply device of claim 1, wherein the feedback controller of the master channel generates the control signal when the voltage feedback signal exceeds a predetermined limit value so that the voltage feedback signal approaches the limit value.

3. the power supply unit of the master channel further comprises a voltage detector for generating a voltage detection signal indicative of an output voltage of the output stage; 2. The power supply device according to claim 1, wherein the feedback controller generates the control signal when the voltage detection signal exceeds a predetermined limit value so that the voltage detection signal approaches the limit value.

4. the multi-channel power supply unit is similarly configured with the feedback controller and the current detector; 4. The power supply device according to claim 1, wherein each power supply unit is selectable between a master mode and a slave mode, and when set to the master mode, the feedback controller is enabled, and when set to the slave mode, the feedback controller is disabled.

5. 5. The power supply device according to claim 1, wherein the master channel is located at the top of the plurality of channels.

6. A power supply unit that can be stacked to form a power supply device, a positive output and a negative output; an output stage that generates an output voltage between the positive output and the negative output in response to a control signal; a current detector that is active when set to a master channel, generates a current detection signal indicative of an output current of the output stage, and is inactive when set to a slave channel; a feedback controller which is active when set to the master channel, generates the control signal so that the current detection signal approaches a target value, and is inactive when set to the slave channel; an interface circuit for transmitting the control signal to other channels when set as the master channel, and for receiving the control signal from the master channel when set as the slave channel; Equipped with When the output stage is set to the master channel, it generates the output voltage based only on the control signal generated by the feedback controller of the same master channel, and when the output stage is set to the slave channel, it generates the output voltage based only on the control signal received by the interface circuit.

7. a voltage detector for generating a voltage detection signal indicative of an output voltage of the output stage; 7. The power supply unit according to claim 6, wherein when set to the master channel, the feedback controller generates the control signal when a voltage feedback signal based on voltage detection signals of all channels exceeds a predetermined limit value so that the voltage feedback signal approaches the limit value.

8. a voltage detector for generating a voltage detection signal indicative of an output voltage of the output stage; 7. The power supply unit of claim 6, wherein when set to the master channel, the feedback controller generates the control signal when the voltage detection signal exceeds a predetermined limit value so that the voltage detection signal approaches the limit value.

9. A power supply device comprising a plurality of power supply units according to any one of claims 6 to 8, stacked together.

10. 10. A test apparatus comprising the power supply apparatus according to claim 1, which supplies power to a device under test.

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