Self-calibration circuit and testing machine
The self-calibration circuit is used to self-calibrate the analog-to-digital converter and the digital-to-analog converter, which solves the high cost problem of traditional calibration methods and achieves efficient precision calibration and improved equipment reliability.
Patent Information
- Application Number
- CN202422802050.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-11-15
AI Technical Summary
Traditional electronic equipment calibration methods rely on external instruments, resulting in high calibration costs and failing to meet the accuracy requirements of high-precision signal source/acquisition source equipment after long-term operation.
A self-calibration circuit is designed, including a calibration signal source, an interface module, and a switching module. The calibration signal source is connected to the module to be calibrated through the switching module, thereby realizing self-calibration of the analog-to-digital conversion module and the digital-to-analog conversion module, simplifying the calibration process and reducing dependence on external instruments.
It realizes precision calibration of analog-to-digital converters and digital-to-analog converters without external equipment, reduces calibration costs, and improves equipment reliability and environmental adaptability.
Smart Images
Figure CN223334668U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor testing technology, and in particular to a self-calibration circuit and a tester. Background Art
[0002] Because electronic components' electrical performance drifts over time and in environments with fluctuating temperatures, this drift can cause high-precision signal source / acquisition equipment to fall below standard accuracy requirements. Therefore, after leaving the factory and operating for extended periods in the field, regular maintenance and calibration are required. Traditional equipment calibration methods rely on external instruments, which carries the disadvantage of high calibration costs. Utility Model Content
[0003] Based on this, it is necessary to provide a self-calibration circuit and a tester that can reduce calibration costs in order to address the above problems.
[0004] A first aspect of the present application provides a self-calibration circuit, comprising a calibration signal source, an interface module, a switching module, and a module to be calibrated, wherein the switching module connects the calibration signal source, the interface module, and the module to be calibrated;
[0005] When the calibration signal source is connected to the module to be calibrated, the switching module outputs the calibration signal of the calibration signal source to the module to be calibrated so as to calibrate the module to be calibrated; when the interface module is connected to the module to be calibrated, the switching module transmits the signal received by the interface module to the module to be calibrated, and / or outputs the signal output by the module to be calibrated through the interface module.
[0006] In one embodiment, the calibration signal source is a signal source calibrated by an external high-precision multimeter.
[0007] In one embodiment, the module to be calibrated includes an analog-to-digital conversion module and a digital-to-analog conversion module connected to the switching module. When the calibration signal source is connected to the analog-to-digital conversion module, the switching module outputs the calibration signal of the calibration signal source to the analog-to-digital conversion module to calibrate the analog-to-digital conversion module; when the analog-to-digital conversion module is connected to the digital-to-analog conversion module, the switching module transmits the output signal of the digital-to-analog conversion module to the calibrated analog-to-digital conversion module to calibrate the digital-to-analog conversion module.
[0008] In one embodiment, the switching module includes a first switch unit and a second switch unit, the first switch unit connects the calibration signal source, the interface module, the analog-to-digital conversion module and the second switch unit, and the second switch unit connects the interface module and the digital-to-analog conversion module.
[0009] In one embodiment, the interface module includes an input end and an output end, the input end is connected to the first switch unit, and the output end is connected to the second switch unit.
[0010] In one embodiment, the first switch unit includes a switch S1, a switch S2, a switch S3, and a switch S4, the first end of the switch S1 is connected to the calibration signal source, the second end of the switch S1 is connected to the first end of the switch S2, the first end of the switch S3, and the first end of the switch S4, the second end of the switch S2 is connected to the input end, the second end of the switch S3 is connected to the analog-to-digital conversion module, and the second end of the switch S4 is connected to the second switch unit.
[0011] In one embodiment, the second switch unit includes a switch S5, a switch S6, and a switch S7, the first end of the switch S5 is connected to the first switch unit, the second end of the switch S5 is connected to the first end of the switch S6 and the first end of the switch S7, the second end of the switch S6 is connected to the output end, and the second end of the switch S7 is connected to the digital-to-analog conversion module.
[0012] In one embodiment, the self-calibration circuit further includes a controller connected to the calibration signal source, the switching module, and the module to be calibrated.
[0013] A second aspect of the present application provides a test machine, comprising the above-mentioned self-calibration circuit.
[0014] The self-calibration circuit and tester described above include a calibration signal source, an interface module, a switching module, and a module to be calibrated. When the switching module connects the calibration signal source to the module to be calibrated, it outputs the calibration signal from the calibration signal source to the module to be calibrated, thereby calibrating the module. When the switching module connects the interface module to the module to be calibrated, it transmits the signal received by the interface module to the module to be calibrated and / or outputs the signal output by the module to be calibrated through the interface module. By switching the switching module, self-calibration of the module to be calibrated can be achieved without the need for external instruments, simplifying the calibration circuit structure and reducing calibration costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is a structural block diagram of a self-calibration circuit in one embodiment;
[0016] Figure 2 is a structural schematic diagram of a self-calibration circuit in one embodiment;
[0017] Figure 3 FIG1 is a schematic diagram showing the principle of calibrating an analog-to-digital converter using a calibration signal source in one embodiment;
[0018] Figure 4 FIG. 1 is a schematic diagram showing the principle of using an analog-to-digital converter to calibrate a digital-to-analog converter in one embodiment. DETAILED DESCRIPTION
[0019] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.
[0021] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.
[0022] When used herein, the singular forms "a", "an", and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, integers, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integers, operations, components, parts, or combinations thereof.
[0023] In one embodiment, Figure 1 As shown, a self-calibration circuit is provided, comprising a calibration signal source 110, an interface module 120, a switching module 130, and a module to be calibrated 140. The switching module 130 connects the calibration signal source 110, the interface module 120, and the module to be calibrated 140. When the calibration signal source 110 is connected to the module to be calibrated 140, the switching module 130 outputs the calibration signal of the calibration signal source 110 to the module to be calibrated 140 to calibrate the module to be calibrated 140. When the interface module 120 is connected to the module to be calibrated 140, the switching module 130 transmits the signal received by the interface module 120 to the module to be calibrated 140, and / or outputs the signal output by the module to be calibrated 140 through the interface module 120.
[0024] Calibration signal source 110 specifically employs a high-precision calibration signal source for providing a calibration reference signal. This reference signal source exhibits the advantages of low temperature drift and time drift, and features a simple structure and is not susceptible to damage. Furthermore, calibration signal source 110 is a signal source calibrated using an external high-precision multimeter. The high-precision calibration signal source can be factory-calibrated using an external high-precision multimeter before shipment, with the calibration data recorded in memory. When a subsequent rapid self-calibration is required on the application side, this calibration data can be used to compensate for errors in the high-precision calibration signal source, ensuring calibration reliability.
[0025] The self-calibration circuit can be integrated on a resource board, such as an analog-digital mixed test board; a module in the self-calibration circuit can also be distributed on other devices outside the resource board.
[0026] The interface module 120 can use a single port or dual ports for signal transmission. The specific structure of the module to be calibrated 140 is not unique and can, for example, include components requiring calibration, such as an analog-to-digital converter (ADC) and a digital-to-analog converter (DAC). The switching module 130 can use a manual switch matrix for channel switching or a controlled switch matrix that switches channels based on received control signals. The controlled switch matrix can be a relay, transistor, or other switch matrix.
[0027] In actual use, the control switching module 130 connects the interface module 120 with the module to be calibrated 140, inputs external signals to the module to be calibrated 140, or outputs signals output by the module to be calibrated 140. When self-calibration is required, the control switching module 130 connects the calibration signal source 110 with the module to be calibrated 140, uses the calibration signal source 110 to output a calibration signal to the module to be calibrated 140, collects the output signal of the module to be calibrated 140, and calibrates the module to be calibrated 140 based on the output signal of the module to be calibrated 140.
[0028] In one embodiment, Figure 2 As shown, the module to be calibrated 140 includes an analog-to-digital conversion module 142 and a digital-to-analog conversion module 144 connected to the switching module 130. When the calibration signal source 110 is connected to the analog-to-digital conversion module 142, the switching module 130 outputs the calibration signal of the calibration signal source 110 to the analog-to-digital conversion module 142 to calibrate the analog-to-digital conversion module 142; when the switching module 130 connects the analog-to-digital conversion module 142 to the digital-to-analog conversion module 144, the output signal of the digital-to-analog conversion module 144 is transmitted to the calibrated analog-to-digital conversion module 142 to calibrate the digital-to-analog conversion module 144.
[0029] The analog-to-digital conversion module 142 may specifically include an analog-to-digital converter conditioning circuit 1422 and an analog-to-digital converter 1424. The analog-to-digital converter conditioning circuit 1422 is connected to the switching module 130 and the analog-to-digital converter 1424, and conditions (e.g., amplifies, filters, etc.) the incoming signal before transmitting it to the analog-to-digital converter 1424. The digital-to-analog conversion module 144 may specifically include a digital-to-analog converter conditioning circuit 1442 and a digital-to-analog converter 1444. The digital-to-analog converter conditioning circuit 1442 is connected to the switching module 130 and the digital-to-analog converter 1444, and conditions (e.g., amplifies, filters, etc.) the signal output by the digital-to-analog converter 1444 before outputting it to the switching module 130.
[0030] Furthermore, the self-calibration circuit also includes a controller 150, which is connected to the calibration signal source 110, the switching module 130, and the module to be calibrated 140. The controller 150 can be a device such as an FPGA, a CPU, or an MCU. The controller 150 is specifically connected to the analog-to-digital converter 1424 and the digital-to-analog converter 1444 in the module to be calibrated 140. The controller 150 is connected to the control terminals of each switch in the switching module 130 and sends control signals to switch channels. After the calibration signal source 110 outputs the calibration signal to the analog-to-digital conversion module 142, the controller 150 receives the output signal of the analog-to-digital converter 1424, compares the output signal with the calibration signal from the calibration signal source 110, and completes the calibration of the analog-to-digital converter 1424. After the calibration of the analog-to-digital converter 1424 is completed, the controller 150 sends a control signal to control the switching module 130 to switch channels and controls the output signal of the digital-to-analog converter 1444. The signal output by the DAC 1444 is transmitted to the ADC module 142 via the switching module 130 , and the DAC 1444 is calibrated by collecting the output signal of the calibrated ADC 1424 .
[0031] In one embodiment, Figure 2 As shown, the switching module 130 includes a first switch unit 132 and a second switch unit 134. The first switch unit 132 is connected to the calibration signal source 110, the interface module 120, the analog-to-digital conversion module 142, and the second switch unit 134. The second switch unit 134 is connected to the interface module 120 and the digital-to-analog conversion module 144. The first switch unit 132 and the second switch unit 134 are also connected to the controller 150 and perform channel switching based on control signals sent by the controller 150. Furthermore, the interface module 120 may include an input terminal 122 and an output terminal 124. The input terminal 122 is connected to the first switch unit 132, and the output terminal 124 is connected to the second switch unit 134.
[0032] Specifically, the first switch unit 132 may include a switch S1, a switch S2, a switch S3, and a switch S4. The first end of the switch S1 is connected to the calibration signal source 110, the second end of the switch S1 is connected to the first end of the switch S2, the first end of the switch S3, and the first end of the switch S4. The second end of the switch S2 is connected to the input terminal 122. The second end of the switch S3 is connected to the analog-to-digital conversion module 142, specifically to the analog-to-digital conversion conditioning circuit 1422. The second end of the switch S4 is connected to the second switch unit 134. The switches S1, S2, S3, and S4 may be relays, and the control ends of the switches S1, S2, S3, and S4 are all connected to the controller 150.
[0033] The second switch unit 134 may include a switch S5, a switch S6, and a switch S7. The first end of the switch S5 is connected to the first switch unit 132, specifically to the second end of the switch S4. The second end of the switch S5 is connected to the first end of the switch S6 and the first end of the switch S7. The second end of the switch S6 is connected to the output terminal 124. The second end of the switch S7 is connected to the digital-to-analog conversion module 144, specifically to the digital-to-analog converter conditioning circuit 1442. Similarly, the switches S5, S6, and S7 may be relays, and the control ends of the switches S5, S6, and S7 are all connected to the controller 150.
[0034] When the acquisition function of analog-to-digital converter 1424 and the output function of digital-to-analog converter 1444 are required to be used normally on site, switches S2 and S3 are closed, and switches S1 and S4 are opened. At this time, external signals can be input to analog-to-digital converter 1424. Switches S6 and S7 are closed, and switch S5 is opened. At this time, the signal of digital-to-analog converter 1444 can be output externally. When the on-site environment changes, such as temperature changes or after long-term use, it is necessary to calibrate the accuracy of analog-to-digital converter 1424 and digital-to-analog converter 1444. The steps are as follows:
[0035] Step 1, such as Figure 3 As shown, switches S1 and S3 are closed, and switches S2, S4, S5, S6, and S7 are opened. The calibration signal output by the calibration signal source 110 is input into the analog-to-digital converter 1424 through the analog-to-digital converter conditioning circuit 1422 for collection, and the data is uploaded to the controller 150. The controller 150 compares the collected value of the analog-to-digital converter 1424 with the factory calibration value of the calibration signal source 110, and performs linear fitting by the least squares method to obtain the linear parameters (K1, B1) of the analog-to-digital converter 1424 and store them in the memory.
[0036] Step 2, such as Figure 4As shown, after the calibration of the analog-to-digital converter 1424 is completed, switches S3, S4, S5, and S7 are closed, and switches S1, S2, and S6 are opened. The controller 150 controls the digital-to-analog converter 1444 to output a signal to the analog-to-digital converter 1424. The analog-to-digital converter 1424 collects the output voltage of the digital-to-analog converter 1444 and uploads it to the controller 150. The controller 150 performs linear fitting based on the collected value of the analog-to-digital converter 1424 to obtain the linear parameters (K2, B2) of the digital-to-analog converter 1444 and stores them in the memory.
[0037] In one embodiment, a test machine is further provided, comprising the above-mentioned self-calibration circuit.
[0038] The self-calibration circuit and tester can simultaneously perform real-time precision calibration on the analog-to-digital converter and the digital-to-analog converter without the need for external equipment, thereby improving product reliability and environmental adaptability; by switching the relay matrix, the calibration circuit structure is simplified and costs are saved.
[0039] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0040] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.
Claims
1. A self-calibration circuit, characterized in that: It includes a calibration signal source, an interface module, a switching module and a module to be calibrated, wherein the switching module is connected to the calibration signal source, the interface module and the module to be calibrated; When the calibration signal source is connected to the module to be calibrated, the switching module outputs the calibration signal of the calibration signal source to the module to be calibrated, so as to calibrate the module to be calibrated; When connecting the interface module with the module to be calibrated, the switching module transmits the signal received by the interface module to the module to be calibrated, and / or outputs the signal output by the module to be calibrated through the interface module.
2. The circuit according to claim 1, wherein: The calibration signal source is a signal source calibrated by an external high-precision multimeter.
3. The circuit according to claim 1, wherein: The module to be calibrated includes an analog-to-digital conversion module and a digital-to-analog conversion module connected to the switching module. When the calibration signal source is connected to the analog-to-digital conversion module, the switching module outputs the calibration signal of the calibration signal source to the analog-to-digital conversion module to calibrate the analog-to-digital conversion module; when the analog-to-digital conversion module is connected to the digital-to-analog conversion module, the switching module transmits the output signal of the digital-to-analog conversion module to the calibrated analog-to-digital conversion module to calibrate the digital-to-analog conversion module.
4. The circuit according to claim 3, characterized in that The switching module includes a first switch unit and a second switch unit, the first switch unit connects the calibration signal source, the interface module, the analog-to-digital conversion module and the second switch unit, and the second switch unit connects the interface module and the digital-to-analog conversion module.
5. The circuit according to claim 4, characterized in that The interface module includes an input end and an output end, the input end is connected to the first switch unit, and the output end is connected to the second switch unit.
6. The circuit according to claim 5, characterized in that The first switch unit includes a switch S1, a switch S2, a switch S3, and a switch S4. The first end of the switch S1 is connected to the calibration signal source, the second end of the switch S1 is connected to the first end of the switch S2, the first end of the switch S3, and the first end of the switch S4, the second end of the switch S2 is connected to the input end, the second end of the switch S3 is connected to the analog-to-digital conversion module, and the second end of the switch S4 is connected to the second switch unit.
7. The circuit according to claim 5, characterized in that The second switch unit includes a switch S5, a switch S6, and a switch S7. The first end of the switch S5 is connected to the first switch unit, the second end of the switch S5 is connected to the first end of the switch S6 and the first end of the switch S7, the second end of the switch S6 is connected to the output end, and the second end of the switch S7 is connected to the digital-to-analog conversion module.
8. The circuit according to any one of claims 1 to 7, characterized in that: The system further includes a controller connected to the calibration signal source, the switching module and the module to be calibrated.
9. A testing machine, characterized in that: The self-calibration circuit comprises the self-calibration circuit according to any one of claims 1 to 8.