Current testing device and electronic equipment

Abstract

The utility model provides a current testing device and an electronic device, the current testing device comprises a voltage output circuit, a current detection circuit, a differential probe and an oscilloscope, the voltage output circuit outputs voltage and current to a chip to be tested through the current detection circuit, and meanwhile, the oscilloscope outputs the voltage and the current to the chip to be tested. The voltage output circuit adjusts self output voltage according to voltage feedback of the voltage feedback end, so that the voltage output to the detected chip is constant as target voltage, the problem of different output voltages caused by voltage drop is avoided, meanwhile, the voltage difference between the two ends of the current detection circuit can be measured by adopting a differential probe, and the detection accuracy is improved. The differential probe outputs a single-end voltage signal, the oscilloscope can obtain current data according to the single-end voltage signal, and the differential probe has high bandwidth, so that sampling of a current signal at a higher frequency band can be realized, and the measurement accuracy of transient current change is improved.

Description

Technical Field

[0001] This utility model belongs to the field of testing technology, and in particular relates to a current testing device and electronic equipment. Background Technology

[0002] With the advancement of integrated circuit technology, the complexity and operating frequency of chips have increased significantly, making chip power consumption and thermal management key concerns, especially in high-performance chips such as CPUs and AI chips. In particular, chip current data can be used to analyze chip power consumption, power quality, dynamic behavior, timing, and thermal output.

[0003] To measure the current of a chip, conventional methods typically employ a current probe, which acquires current data by being clamped into the circuit. However, using a current probe presents the following problems:

[0004] 1. Modern chips, especially large-scale integrated circuits and high-frequency processors, operate at frequencies of several GHz, resulting in extremely rapid current changes. At such high frequencies, the response time and bandwidth of current probes may not be able to fully capture the transient current changes of the chip, leading to inaccurate measurement results.

[0005] 2. In chip testing, current probes typically clamp the power supply line to test the magnetic field in the current path. Adding this transmission line inevitably increases the voltage drop at the actual pins of the chip under test, leading to errors in the test results. Utility Model Content

[0006] The purpose of this invention is to provide a current testing device that solves the problem of inaccurate measurement when using traditional current probes to test the current of the chip under test.

[0007] A first aspect of this utility model provides a current testing device, comprising:

[0008] A voltage output circuit includes a voltage output terminal and a voltage feedback terminal. The voltage feedback terminal is connected to the test point of the chip under test. The voltage output circuit adjusts the output voltage of the voltage output terminal based on the feedback voltage of the voltage feedback terminal so that the voltage of the voltage feedback terminal is constant as the target voltage.

[0009] A current detection circuit is connected between the voltage output terminal of the voltage output circuit and the test point of the chip under test. The current detection circuit is used to detect the current of the chip under test.

[0010] A differential probe is connected to both ends of the current detection circuit to differentially amplify the voltage across the current detection circuit and output a single-ended voltage signal.

[0011] An oscilloscope, connected to the differential probe, is used to process the single-ended voltage signal and obtain the current data of the chip under test.

[0012] Optionally, the voltage output circuit includes a power chip, the power input terminal of which is used to input the supply voltage, the power output terminal of which constitutes the voltage output terminal of the voltage output circuit, and the voltage feedback terminal of which constitutes the feedback terminal of the voltage output circuit.

[0013] Optionally, the power chip further includes at least:

[0014] Reference voltage source, used to output the first reference voltage;

[0015] The comparator has its non-inverting input connected to the output of the reference voltage source and its inverting input connected to the feedback of the power supply chip. The comparator is used to compare the voltage at the feedback of the power supply chip with the first reference voltage and output a comparison signal.

[0016] A driver, connected to the comparator, outputs a switch control signal based on the comparison signal;

[0017] A switching circuit is connected between the power input terminal and the ground terminal of the power chip. The switching circuit includes a first driving transistor and a second driving transistor connected in series. The connection node of the first driving transistor and the second driving transistor is connected to the power output terminal of the power chip. The control terminals of the first driving transistor and the second driving transistor are respectively connected to the driver. The first driving transistor and the second driving transistor are converted by the switching control signal to output the output voltage of the voltage output circuit.

[0018] Optionally, the voltage output circuit includes an error amplifier and a third driver transistor;

[0019] The first end of the third driving transistor is used to input the power supply, the second end of the third driving transistor constitutes the voltage output terminal of the voltage output circuit, the control terminal of the third driving transistor is connected to the output terminal of the error amplifier, the non-inverting input terminal of the error amplifier is used to input the second reference voltage, and the inverting input terminal of the error amplifier constitutes the voltage feedback terminal of the voltage output circuit.

[0020] Optionally, the current detection circuit includes a fixed-value resistor.

[0021] Optionally, the current detection circuit includes:

[0022] A range selection resistor circuit is connected between the voltage output terminal of the voltage output circuit and the test point of the chip under test. The range selection resistor circuit is triggered by the resistance adjustment signal to form a transmission path with corresponding impedance between the voltage output terminal of the voltage output circuit and the test point of the chip under test.

[0023] Optionally, the current detection circuit further includes a controller connected to the gear selection resistor circuit, and the controller outputs a resistance adjustment signal of a corresponding magnitude based on control commands.

[0024] Optionally, the gear selection resistor circuit includes multiple resistor branches connected in parallel;

[0025] The resistor branch includes a switch and a first resistor connected in series, and the resistance value of the first resistor is different in each resistor branch.

[0026] Optionally, the differential probe includes:

[0027] The first detection electrode is in contact with the input terminal of the current detection circuit and transmits the input voltage of the current detection circuit.

[0028] The second detection electrode is in contact with the output terminal of the current detection circuit and transmits the output voltage of the current detection circuit.

[0029] The signal interface is connected to the oscilloscope.

[0030] A differential amplifier circuit is connected to the first detection electrode, the second detection electrode, and the signal interface, respectively. The differential amplifier circuit is used to differentially amplify the voltage across the current detection circuit and output the single-ended voltage signal. The single-ended voltage signal is transmitted to the oscilloscope through the signal interface.

[0031] Optionally, the differential amplifier circuit includes an operational amplifier, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a first voltage follower, and a second voltage follower;

[0032] The first end of the second resistor, the first end of the first capacitor, the input terminal of the first voltage follower, and the first probe electrode are connected. The first end of the third resistor, the first end of the second capacitor, the input terminal of the second voltage follower, and the second probe electrode are connected. The second end of the second resistor, the second end of the first capacitor, the second end of the third resistor, and the second end of the second capacitor are grounded. The output terminal of the first voltage follower is connected to the first end of the fourth resistor. The output terminal of the second voltage follower is connected to the first end of the fifth resistor. The second end of the fourth resistor is connected to the first input terminal of the operational amplifier. The second end of the fifth resistor is connected to the second input terminal of the operational amplifier. The output terminal of the operational amplifier is connected to the signal interface.

[0033] Optionally, the current testing device further includes:

[0034] A filtering circuit is connected to the test point of the chip under test, and the filtering circuit is used to filter the voltage of the test point of the chip under test.

[0035] Optionally, the filtering circuit includes a filter capacitor;

[0036] The first end of the filter capacitor is connected to the test point of the chip under test, and the second end of the filter capacitor is grounded.

[0037] This invention also provides an electronic device, including a current testing device as described in the above scheme, wherein the current testing device is used to connect to the chip under test.

[0038] Optionally, the chip under test includes a sensor chip or the chip under test includes a signal sensing chip and at least a processing chip that receives signals from the signal sensing chip, wherein the processing chip receives the output signal of the current testing device.

[0039] The beneficial effects of this utility model embodiment compared with the prior art are as follows: The current testing device includes a voltage output circuit, a current detection circuit, a differential probe, and an oscilloscope. The voltage output circuit outputs voltage and current to the chip under test through the current detection circuit. At the same time, the voltage output circuit adjusts its own output voltage according to the voltage feedback of the voltage feedback terminal, so that the voltage output to the chip under test is constant at the target voltage, avoiding the problem of different output voltages due to voltage drop. Meanwhile, by using a differential probe, the voltage difference between the two ends of the current detection circuit can be measured, thereby indirectly measuring the current output to the chip under test. The differential probe outputs a single-ended voltage signal, and the oscilloscope can obtain current data based on the single-ended voltage signal. Furthermore, the differential probe has a high bandwidth, which can realize sampling of current signals in higher frequency bands, improving the measurement accuracy of transient current changes. Attached Figure Description

[0040] Figure 1 A schematic diagram of a first module of the current testing device provided in an embodiment of this utility model;

[0041] Figure 2 A schematic diagram of a second module of the current testing device provided in this embodiment of the present invention;

[0042] Figure 3 A schematic diagram of a third module of the current testing device provided in this embodiment of the present invention and a schematic diagram of the filter circuit;

[0043] Figure 4 A schematic diagram of a fourth module of the current testing device and a schematic diagram of a first circuit of the voltage output circuit provided in the embodiments of this utility model;

[0044] Figure 5 A circuit diagram of the power supply chip provided in an embodiment of this utility model;

[0045] Figure 6 A second circuit diagram of the voltage output circuit provided in this embodiment of the utility model;

[0046] Figure 7 A schematic diagram of the fifth module of the current testing device provided in this embodiment of the utility model;

[0047] Figure 8 A schematic diagram of the sixth module of the current testing device provided in this embodiment of the present utility model and a circuit diagram of the range selection resistor circuit;

[0048] Figure 9 A circuit diagram of the differential probe provided in an embodiment of this utility model;

[0049] Figure 10 A circuit diagram of the differential amplifier circuit provided in an embodiment of this utility model. Detailed Implementation

[0050] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] This embodiment of the invention provides a current testing device 100 for outputting voltage to a chip under test (DUT) 200. The voltage output to the DUT can be a power supply voltage or a test voltage. The current testing device 100 can be connected to the power supply terminal of the DUT 200, or to a corresponding pin or node of the DUT 200 to form a test point, thereby performing current testing on the target point of the DUT 200. The current testing device 100 can acquire current data from the DUT 200, which can be used to analyze the power consumption, power quality, dynamic behavior, timing, and thermal output of the DUT 200.

[0053] For example, the current change of the chip under test 200 under different loads can be obtained, and the power consumption of the chip under test 200 can be monitored, thereby optimizing the power management of the chip to achieve the purpose of reducing power consumption and improving energy efficiency.

[0054] The peak power consumption and dynamic current characteristics of the chip under test 200 when processing large amounts of data can be obtained to optimize the balance between chip performance and power consumption.

[0055] It can also acquire current data and corresponding heat changes when the chip under test 200 is operating at high frequency, thus preventing the chip from overheating.

[0056] It can also capture power supply noise, transient current and interference data during the test, and use this data to optimize the power supply system design and improve the stability and performance of the chip under test 200.

[0057] Furthermore, during dynamic testing, the current characteristics of the chip under test 200 under different operating modes can be captured. By analyzing the current waveform, peak power consumption periods and low power consumption states can be identified, thereby optimizing the chip design.

[0058] like Figure 1 As shown, the current testing device 100 includes:

[0059] The voltage output circuit 10 includes a voltage output terminal Vout and a voltage feedback terminal FB. The voltage feedback terminal FB is connected to the test point of the chip under test 200. The voltage output circuit 10 adjusts the output voltage of the voltage output terminal Vout based on the feedback voltage of the voltage feedback terminal FB so that the voltage of the voltage feedback terminal FB is constant as the target voltage.

[0060] The current detection circuit 20 is connected between the voltage output terminal Vout of the voltage output circuit 10 and the test point of the chip under test 200. The current detection circuit 20 is used to detect the current of the chip under test 200.

[0061] The differential probe 30 is connected to both ends of the current detection circuit 20 and is used to differentially amplify the voltage across the current detection circuit 20 and output a single-ended voltage signal.

[0062] The oscilloscope 40 is connected to the differential probe 30 and is used to process the single-ended voltage signal and obtain the current data of the chip under test 200. Furthermore, it can display the current data of the chip under test 200.

[0063] In this embodiment, the voltage output circuit 10 outputs a test voltage or a supply voltage based on a test command or a trigger operation. Assuming the output voltage of the voltage output circuit 10 is a first voltage, the first voltage generates a certain voltage drop through the current detection circuit 20, and outputs a current signal and the voltage after the voltage drop to the chip under test 200. Assuming the voltage input to the chip under test 200 is a second voltage, the second voltage is synchronously fed back to the voltage feedback terminal FB of the voltage output circuit 10. The voltage output circuit 10 compares the second voltage with the internal target voltage and adjusts the magnitude of the first voltage according to the comparison result to achieve voltage feedback regulation. Finally, the second voltage output to the chip under test 200 is kept constant at the target voltage, avoiding the problem of different output voltages due to voltage drop and reducing measurement errors.

[0064] For example, when the second voltage is greater than the target voltage, the voltage output circuit 10 adjusts and reduces the magnitude of the first voltage, and when the second voltage is less than the target voltage, the voltage output circuit 10 increases the first voltage. When the voltage drop of the current detection circuit 20 is constant, the second voltage is eventually made constant at the target voltage. The target voltage is the target power supply voltage or target test voltage input to the chip under test 200. Through feedback adjustment, the target voltage and current output to the chip under test 200 can be stabilized, thereby improving the measurement accuracy.

[0065] The current detection circuit 20 is used to detect the current output to the chip under test 200. At the same time, the first voltage and the second voltage are output to the differential probe 30. The differential probe 30 is a voltage differential probe with a bandwidth range of several GHz to tens of GHz. The differential probe 30 can measure the terminal voltage of the current detection circuit 20. By measuring the change of the terminal voltage, the change of the current signal is indirectly measured. Furthermore, due to the high bandwidth characteristic of the differential probe 30, it can achieve sampling of current signals in the high-frequency band, improve the ability to capture and respond to transient current changes, and thus improve the accuracy of current detection.

[0066] The differential probe 30 performs differential amplification on the first voltage and the second voltage and outputs a single-ended voltage signal. The magnitude of the single-ended voltage signal changes with the magnitude of the current signal. The single-ended voltage signal can be output to the oscilloscope 40 through a transmission line. The bandwidth of the oscilloscope 40 can be from several GHz to tens of GHz, and the sampling rate can be tens of Gsa / s. After measuring the single-ended voltage signal, the oscilloscope 40 can process the single-ended voltage signal through its built-in calculation function and restore the data and waveform of the current signal.

[0067] In this circuit, when the voltage drop across the current detection circuit 20 is constant, a larger current signal leads to a larger ratio of the voltage drops between the first and second voltages, and a larger proportion of the single-ended voltage signal. Conversely, a smaller current signal leads to a smaller ratio of the voltage drops between the first and second voltages, and a smaller proportion of the single-ended voltage signal. By acquiring the magnitude and changes in the single-ended voltage signal and calculating the corresponding gain, the magnitude and changes in the current signal can be reconstructed, thus obtaining the current data of the chip under test (DUT) 200. This current data can be used for subsequent analysis of the DUT 200's power consumption, power quality, dynamic behavior, timing, and thermal output. Furthermore, the DUT 200 can be an integrated circuit (IC), including but not limited to SOCs, CPUs, NPUs, MCUs, and GPUs.

[0068] Furthermore, in an optional embodiment, such as Figure 2 As shown, the current testing device 100 also includes:

[0069] A filter circuit 50 is connected to the test point of the chip under test 200. The filter circuit 50 filters the voltage at the test point of the chip under test 200. The filter circuit 50 filters the second voltage, eliminating corresponding noise interference and ensuring the working performance of the chip under test 200 and the feedback adjustment accuracy of the voltage output circuit 10. This helps avoid glitches or voltage spikes in the output second voltage, which could affect the working performance of the chip under test 200 and the feedback adjustment accuracy of the voltage output circuit 10.

[0070] The filter circuit 50 can be selected from different filter components or circuits as needed. In one optional embodiment, such as... Figure 3 As shown, the filter circuit 50 includes a filter capacitor C3. The first end of the filter capacitor C3 is connected to the test point of the chip under test 200, and the second end of the filter capacitor C3 is grounded. The filter capacitor C3 filters the second voltage and eliminates the corresponding noise interference.

[0071] The voltage output circuit 10 can employ a corresponding voltage regulation circuit, chip, etc., as shown in an optional embodiment, such as... Figure 4As shown, the voltage output circuit 10 includes a power supply chip 11. The power input terminal Vin of the power supply chip 11 is used to input the supply voltage VDD. The power output terminal of the power supply chip 11 constitutes the voltage output terminal Vout of the voltage output circuit 10. The voltage feedback terminal FB of the power supply chip 11 constitutes the feedback terminal of the voltage output circuit 10. The power supply chip can be a DC-DC converter or an LDO, etc.

[0072] In this embodiment, the power chip 11 has a built-in reference voltage, which can be selected as the target voltage. When the second voltage is input to the chip under test 200, it is fed back to the voltage feedback terminal FB of the voltage output circuit 10. The voltage output circuit 10 compares the second voltage with the internal reference voltage and adjusts the magnitude of the first voltage according to the comparison result to realize voltage feedback regulation. Finally, the second voltage output to the chip under test 200 is kept constant as the reference voltage, avoiding the problem of different output voltages due to voltage drop and reducing measurement error.

[0073] The power supply chip 11 can be a corresponding comparator U1, a switching output circuit, etc. In an optional embodiment, such as... Figure 5 As shown, the power chip 11 also includes at least:

[0074] Reference voltage source 111 is used to output the first reference voltage Vref1;

[0075] Comparator U1 has its non-inverting input connected to the output of reference voltage source 111 and its inverting input connected to the feedback of power supply chip 11. Comparator U1 is used to compare the voltage at the feedback of power supply chip 11 with the first reference voltage Vref1 and output a comparison signal.

[0076] Driver 112 is connected to comparator U1 and outputs a switch control signal based on the comparison signal;

[0077] The switching circuit 113 is connected between the power input terminal Vin and the ground terminal of the power chip 11. The switching circuit 113 includes a first driving transistor Q1 and a second driving transistor Q2 connected in series. The connection node of the first driving transistor Q1 and the second driving transistor Q2 is connected to the power output terminal of the power chip 11. The control terminals of the first driving transistor Q1 and the second driving transistor Q2 are respectively connected to the driver 112. The first driving transistor Q1 and the second driving transistor Q2 are converted by the switching control signal to output the voltage of the output voltage output circuit 10.

[0078] In this embodiment, the switch drive signal can be a PWM signal. The driver 112 outputs two corresponding PWM signals to the first driver transistor Q1 and the second driver transistor Q2 based on the magnitude of the received comparison signal. The comparator U1 compares the second voltage with the first reference voltage Vref1. When the second voltage is greater than the first reference voltage Vref1, the comparison signal becomes smaller, the duty cycle of the PWM signal output by the driver 112 to the first driver transistor Q1 decreases, and the duty cycle of the PWM signal output to the second driver transistor Q2 increases, resulting in a smaller output first voltage. Correspondingly, the second voltage after voltage drop by the current detection circuit 20 decreases. Conversely, when the second voltage is less than the first reference voltage Vref1, the comparison signal becomes larger, the duty cycle of the PWM signal output by the driver 112 to the first driver transistor Q1 increases, and the duty cycle of the PWM signal output to the second driver transistor Q2 decreases, resulting in a larger output first voltage. Correspondingly, the second voltage after voltage drop by the current detection circuit 20 increases. By adjusting the duty cycle of the PWM signals of the two driver transistors through feedback, the second voltage is finally stabilized at the first reference voltage Vref1, which is the target voltage.

[0079] The driver 112 can be a structure with a connected controller and signal amplifier, and the first driving transistor Q1 and the second driving transistor Q2 can be MOS transistors.

[0080] In another alternative embodiment, such as Figure 6 As shown, the voltage output circuit 10 includes an error amplifier U2 and a third driver transistor Q3;

[0081] The first terminal of the third driving transistor Q3 is used to input the power supply, the second terminal of the third driving transistor Q3 constitutes the voltage output terminal Vout of the voltage output circuit 10, the control terminal of the third driving transistor Q3 is connected to the output terminal of the error amplifier U2, the non-inverting input terminal of the error amplifier U2 is used to input the second reference voltage Vref2, and the inverting input terminal of the error amplifier U2 constitutes the voltage feedback terminal FB of the voltage output circuit 10.

[0082] In this embodiment, the second reference voltage Vref2 is compared with the second voltage obtained from feedback, and an error signal is output to the third driving transistor Q3. When the feedback second voltage drops, the second voltage is compared with the second reference voltage Vref2. When the second voltage is less than the second reference voltage Vref2, the error amplifier U2 will generate more current and input it to the gate of the third driving transistor Q3, reducing the voltage drop of the third driving transistor Q3. The second voltage after the voltage drop through the current detection circuit 20 increases, thereby achieving voltage regulation.

[0083] When the feedback second voltage rises, it is compared with the second reference voltage Vref2. When the second voltage is greater than the second reference voltage Vref2, the error amplifier U2 will generate less current and input it to the gate of the third driving transistor Q3, increasing the voltage drop of the third driving transistor Q3. After the voltage drop through the current detection circuit 20, the second voltage becomes smaller, thus achieving voltage regulation and keeping the second voltage constant at the second reference voltage Vref2, which is the target voltage.

[0084] The third driving transistor Q3 can be a MOSFET.

[0085] The current detection circuit 20 includes a fixed resistance resistor and a range selector resistor circuit 21. That is, the current detection circuit 20 is generally a resistive device and is also designed to allow the resistance range to be changed according to different measurement needs.

[0086] In order to adjust the current level, the resistance value of the current detection circuit 20 can be changed. Different resistance values ​​result in different output currents. Correspondingly, in an optional embodiment, such as... Figure 7 As shown, the current detection circuit 20 includes:

[0087] The range selection resistor circuit 21 is connected between the voltage output terminal Vout of the voltage output circuit 10 and the test point of the chip under test 200. The range selection resistor circuit 21 is triggered by the resistance adjustment signal to form a transmission path with corresponding impedance and is connected between the voltage output terminal Vout of the voltage output circuit 10 and the test point of the chip under test 200.

[0088] Furthermore, the current detection circuit 20 also includes a controller 22, which is connected to the gear selection resistor circuit 21. The controller 22 outputs a resistance adjustment signal of the corresponding magnitude based on the control command.

[0089] In this embodiment, the controller 22 can be connected to the adjustment module or the control module and receive corresponding control commands. Based on the control commands, it outputs different resistance adjustment signals. The resistance adjustment signal adjusts the range selection resistor circuit 21 to switch to different impedances. When the impedance of the range selection resistor circuit 21 changes, according to Ohm's law, the output current signal changes in a negative correlation. That is, when the impedance increases, the current signal decreases, and when the impedance decreases, the current signal increases. By switching the impedance of the range selection resistor circuit 21, the output current of the voltage output circuit 10 can be switched to achieve different current range selection.

[0090] The controller 22 can be an MCU, CPU, etc.

[0091] The gear selection resistor circuit 21 can be composed of different resistors and switches. In one optional embodiment, such as... Figure 8As shown, the gear selection resistor circuit 21 includes multiple resistor branches connected in parallel.

[0092] The resistor branch includes a switch K1 and a first resistor R1 connected in series. The control terminal of switch K1 is connected to the control terminal of controller 22. The resistance value of the first resistor R1 is different in each resistor branch.

[0093] In this embodiment, the controller 22 can output different combinations of switch control signals to select one or more resistor branches to be turned on, and connect the first resistor R1 of one or more of these branches in series between the voltage output circuit 10 and the chip under test 200 to achieve switching of different impedances, thereby achieving selection of different current levels.

[0094] Differential probe 30 is a voltage differential probe, which can employ appropriate connection components and processing circuitry. In one optional embodiment, such as... Figure 9 As shown, the differential probe 30 includes:

[0095] The first detection electrode 31 is in contact with the input terminal of the current detection circuit 20 and transmits the input voltage of the current detection circuit 20.

[0096] The second detection electrode 32 is in contact with the output terminal of the current detection circuit 20 and transmits the output voltage of the current detection circuit 20.

[0097] Signal interface 34 is connected to oscilloscope 40;

[0098] The differential amplifier circuit 33 is connected to the first detection electrode 31, the second detection electrode 32 and the signal interface 34 respectively. The differential amplifier circuit 33 is used to differentially amplify the voltage across the current detection circuit 20 and output a single-ended voltage signal. The single-ended voltage signal is transmitted to the oscilloscope 40 through the signal interface 34.

[0099] In this embodiment, the first detection electrode 31 and the second detection electrode 32 can be connected to the input and output terminals of the current detection circuit 20 by contact or clamping. In an optional embodiment, the first detection electrode 31 and the second detection electrode 32 can be in a clamping structure, clamped between the input and output terminals of the current detection circuit 20, and transmitting the first voltage and the second voltage to the differential amplifier circuit 33. The differential amplifier circuit 33 differentially amplifies the first voltage and the second voltage to obtain a single-ended voltage signal. The magnitude of the single-ended voltage signal changes with the magnitude of the current signal. The single-ended voltage signal can be output to the oscilloscope 40 through the signal interface 34 and the transmission line connected to the signal interface 34. After the oscilloscope 40 measures the single-ended voltage signal, it can process the single-ended voltage signal through the built-in calculation function of the oscilloscope 40 and restore the data and waveform of the current signal.

[0100] The differential amplifier circuit 33 can perform differential conversion between the first voltage and the second voltage. It can employ a corresponding operational amplifier U3 or a switching transistor, etc. In an optional embodiment, such as... Figure 10 As shown, the differential amplifier circuit 33 includes an operational amplifier U3, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2, a first voltage follower U4, and a second voltage follower U5.

[0101] The first terminal of the second resistor R2, the first terminal of the first capacitor C1, the input terminal of the first voltage follower U4, and the first detection electrode 31 are connected. The first terminal of the third resistor R3, the first terminal of the second capacitor C2, the input terminal of the second voltage follower U5, and the second detection electrode 32 are connected. The second terminal of the second resistor R2, the second terminal of the first capacitor C1, the second terminal of the third resistor R3, and the second terminal of the second capacitor C2 are grounded. The output terminal of the first voltage follower U4 is connected to the first terminal of the fourth resistor R4. The output terminal of the second voltage follower U5 is connected to the first terminal of the fifth resistor R5. The second terminal of the fourth resistor R4 is connected to the first input terminal of the operational amplifier U3. The second terminal of the fifth resistor R5 is connected to the second input terminal of the operational amplifier U3. The output terminal of the operational amplifier U3 is connected to the signal interface 34.

[0102] In this embodiment, the second resistor R2 and the third resistor R3 divide and convert the first voltage and the second voltage, thereby outputting two voltage differential signals with opposite polarities and equal absolute values ​​to the first voltage follower U4 and the second voltage follower U5. The first capacitor C1 and the second capacitor C2 are used to filter the two voltage differential signals. The first voltage follower U4 and the second voltage follower U5 are used to isolate the current signal and reduce the influence of the current signal. The two voltage differential signals are output to the fourth resistor R4 and the fifth resistor R5 through the first voltage follower U4 and the second voltage follower U5. After being divided by the fourth resistor R4 and the fifth resistor R5, the two voltage differential signals are output to the operational amplifier U3 and output a single-ended voltage signal. After the oscilloscope 40 measures the single-ended voltage signal, it can process the single-ended voltage signal through the built-in operation function of the oscilloscope 40 and restore the data and waveform of the current signal.

[0103] This utility model also provides an electronic device, including a current testing device 100 as described in the above scheme, which is used to connect to the chip under test 200. This electronic device can be a test platform specifically for chip testing and verification, or it can be a device that receives and processes signals, such as receiving image, voice, or text signals.

[0104] Furthermore, in some applications, the chip under test 200 includes a sensor chip or a signal sensing chip and at least a processing chip that receives signals from the signal sensing chip. The processing chip receives the output signal from the current testing device. This electronic device can correspond to an image sensor chip (such as a sensor chip), with the image sensor chip serving as the chip under test 200, measuring the current of the image sensor chip. Alternatively, the electronic device can be a system composed of an image sensor chip and a processing chip (such as a SOC chip), i.e., a signal sensing chip and at least a processing chip that receives signals from the signal sensing chip. In this case, the current testing device 100 can be connected to the SOC chip to perform current testing.

[0105] The beneficial effects of this utility model embodiment compared with the prior art are as follows: The current testing device 100 includes a voltage output circuit 10, a current detection circuit 20, a differential probe 30, and an oscilloscope 40. The voltage output circuit 10 outputs voltage and current to the chip under test 200 through the current detection circuit 20. At the same time, the voltage output circuit 10 adjusts its own output voltage according to the voltage feedback of the voltage feedback terminal FB, so that the voltage output to the chip under test 200 is constant at the target voltage, avoiding the problem of different output voltages due to voltage drop. Meanwhile, by using the differential probe 30, the voltage difference between the two ends of the current detection circuit 20 can be measured, thereby indirectly measuring the current output to the chip under test 200. The differential probe 30 outputs a single-ended voltage signal, and the oscilloscope 40 can restore and display the current data based on the single-ended voltage signal. Furthermore, the differential probe 30 has a high bandwidth, which can realize sampling of current signals in higher frequency bands, improving the measurement accuracy of transient current changes.

[0106] Specifically, the power chip 11 outputs power to the chip under test 200. The current passes through the current detection circuit 20. According to Ohm's law, a voltage difference will be generated across the current detection circuit 20. The voltage difference can be measured using a differential probe 30, which can be selected based on different accuracy and bandwidth requirements. After the oscilloscope 40 measures the differential voltage signal, its built-in processing function can be used to process the voltage signal and display the actual voltage signal. This achieves accurate capture of high-frequency current fluctuations and efficient power consumption analysis.

[0107] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A current testing device, characterized in that, include: A voltage output circuit includes a voltage output terminal and a voltage feedback terminal. The voltage feedback terminal is connected to the test point of the chip under test. The voltage output circuit adjusts the output voltage of the voltage output terminal based on the feedback voltage of the voltage feedback terminal so that the voltage of the voltage feedback terminal is constant as the target voltage. A current detection circuit is connected between the voltage output terminal of the voltage output circuit and the test point of the chip under test. The current detection circuit is used to detect the current of the chip under test. A differential probe is connected to both ends of the current detection circuit to differentially amplify the voltage across the current detection circuit and output a single-ended voltage signal. An oscilloscope, connected to the differential probe, is used to process the single-ended voltage signal and obtain the current data of the chip under test.

2. The current testing device as described in claim 1, characterized in that, The voltage output circuit includes a power chip. The power input terminal of the power chip is used to input the supply voltage. The power output terminal of the power chip constitutes the voltage output terminal of the voltage output circuit. The voltage feedback terminal of the power chip constitutes the feedback terminal of the voltage output circuit.

3. The current testing device as described in claim 2, characterized in that, The power chip further includes at least: Reference voltage source, used to output the first reference voltage; The comparator has its non-inverting input connected to the output of the reference voltage source and its inverting input connected to the feedback of the power supply chip. The comparator is used to compare the voltage at the feedback of the power supply chip with the first reference voltage and output a comparison signal. A driver, connected to the comparator, outputs a switch control signal based on the comparison signal; A switching circuit is connected between the power input terminal and the ground terminal of the power chip. The switching circuit includes a first driving transistor and a second driving transistor connected in series. The connection node of the first driving transistor and the second driving transistor is connected to the power output terminal of the power chip. The control terminals of the first driving transistor and the second driving transistor are respectively connected to the driver. The first driving transistor and the second driving transistor are converted by the switching control signal to output the output voltage of the voltage output circuit.

4. The current testing device as described in claim 1, characterized in that, The voltage output circuit includes an error amplifier and a third driver transistor; The first end of the third driving transistor is used to input the power supply, the second end of the third driving transistor constitutes the voltage output terminal of the voltage output circuit, the control terminal of the third driving transistor is connected to the output terminal of the error amplifier, the non-inverting input terminal of the error amplifier is used to input the second reference voltage, and the inverting input terminal of the error amplifier constitutes the voltage feedback terminal of the voltage output circuit.

5. The current testing device as described in claim 1, characterized in that, The current detection circuit includes a fixed-value resistor, or the current detection circuit includes a range selection resistor circuit, wherein: The range selection resistor circuit is connected between the voltage output terminal of the voltage output circuit and the test point of the chip under test. Triggered by the resistance adjustment signal, it forms a transmission path with corresponding impedance between the voltage output terminal of the voltage output circuit and the test point of the chip under test.

6. The current testing device as described in claim 5, characterized in that, When the current detection circuit includes a range selection resistor circuit: The gear selection resistor circuit includes multiple resistor branches connected in parallel. Each resistor branch includes a switch and a first resistor connected in series, and the resistance value of the first resistor in each resistor branch is different; and / or, The current detection circuit also includes a controller connected to the gear selection resistor circuit. The controller outputs a resistance adjustment signal of a corresponding magnitude based on control commands.

7. The current testing device as described in claim 1, characterized in that, The differential probe includes: The first detection electrode is in contact with the input terminal of the current detection circuit and transmits the input voltage of the current detection circuit. The second detection electrode is in contact with the output terminal of the current detection circuit and transmits the output voltage of the current detection circuit. The signal interface is connected to the oscilloscope. A differential amplifier circuit is connected to the first detection electrode, the second detection electrode, and the signal interface, respectively. The differential amplifier circuit is used to differentially amplify the voltage across the current detection circuit and output the single-ended voltage signal. The single-ended voltage signal is transmitted to the oscilloscope through the signal interface.

8. The current testing device as described in claim 7, characterized in that, The differential amplifier circuit includes an operational amplifier, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a first voltage follower, and a second voltage follower. The first end of the second resistor, the first end of the first capacitor, the input terminal of the first voltage follower, and the first probe electrode are connected. The first end of the third resistor, the first end of the second capacitor, the input terminal of the second voltage follower, and the second probe electrode are connected. The second end of the second resistor, the second end of the first capacitor, the second end of the third resistor, and the second end of the second capacitor are grounded. The output terminal of the first voltage follower is connected to the first end of the fourth resistor. The output terminal of the second voltage follower is connected to the first end of the fifth resistor. The second end of the fourth resistor is connected to the first input terminal of the operational amplifier. The second end of the fifth resistor is connected to the second input terminal of the operational amplifier. The output terminal of the operational amplifier is connected to the signal interface.

9. The current testing device according to any one of claims 1 to 8, characterized in that, The current testing device also includes: A filtering circuit is connected to the test point of the chip under test, and the filtering circuit is used to filter the voltage of the test point of the chip under test.

10. The current testing device as described in claim 9, characterized in that, The filtering circuit includes a filtering capacitor; The first end of the filter capacitor is connected to the test point of the chip under test, and the second end of the filter capacitor is grounded.

11. An electronic device, characterized in that, The electronic device includes a current testing device as described in any one of claims 1-10, the current testing device being used to connect to the chip under test.

12. The electronic device according to claim 11, characterized in that, The chip under test includes a sensor chip or the chip under test includes a signal sensing chip and at least a processing chip that receives signals from the signal sensing chip, wherein the processing chip receives the output signal of the current testing device.

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