Digital board calibration device, method and system

Abstract

The invention relates to a digital board calibration device, method and system, and the device comprises a calibration bus which is used for connecting a universal meter; the reference source module is connected with the calibration bus; the function modules are connected with the calibration bus, and the number of the function modules is more than two; wherein the reference source module is calibrated through the universal meter, and the uncalibrated function module is calibrated through the universal meter, the calibrated reference source module or the calibrated function module, so that the frequency of calibration by using the universal meter is reduced, and the calibration efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of equipment calibration, and in particular to a digital board calibration device, method and system. Background Art

[0002] Semiconductor automated testing refers to the use of semiconductor testers to test various parameters of semiconductor devices, eliminate defective products and control the quality of semiconductor devices before they leave the factory. In order to ensure the accuracy of output data and prevent the output data from being too large or too small, the semiconductor tester needs to be calibrated before testing semiconductor devices.

[0003] Semiconductor testers are generally made of PE (Pin Electronic) chips due to their high integration, and most of these chips have DACs (Digital-to-Analogue Conversion) integrated inside, whose output characteristics are often not linear, and some are even discontinuous. The traditional semiconductor tester calibration method is to calibrate each digital board of the semiconductor tester one by one through an external multimeter. Each time a digital board is tested, the connection method of the multimeter needs to be changed, which is time-consuming and labor-intensive, and has the disadvantage of low calibration efficiency. Summary of the invention

[0004] Based on this, it is necessary to provide a digital board calibration device, method and system that can improve calibration efficiency in order to address the above problems.

[0005] The first aspect of the present application provides a digital board calibration device, comprising:

[0006] Calibration bus, used to connect the multimeter;

[0007] A reference source module connected to the calibration bus;

[0008] A functional module connected to the calibration bus, wherein the number of the functional modules is more than two;

[0009] The reference source module is calibrated by the multimeter, and the uncalibrated functional module is calibrated by the multimeter, the calibrated reference source module or the calibrated functional module.

[0010] In one embodiment, the reference source module includes a first DAC module, the functional module includes a resistor network module, a first ADC (Analogue-to-Digital Conversion) module and a PE module, the first DAC module and the resistor network module are calibrated by the multimeter, and the first ADC module is calibrated by the calibrated first DAC module.

[0011] In one embodiment, the reference source module includes a high-precision reference source chip, the functional module includes a resistor network module, a second ADC module, a second DAC module and a PE module, and the voltage accuracy of the high-precision reference source chip is greater than the voltage accuracy of the second DAC module; the high-precision reference source chip and the resistor network module are calibrated by the multimeter, the second ADC module is calibrated by the calibrated high-precision reference source chip, and the second DAC module is calibrated by the calibrated second ADC module.

[0012] In one of the embodiments, the digital board calibration device also includes: an external ADC module, which is connected to the PE module and the calibration bus; the external ADC module is calibrated through a calibrated DAC module, and the PE module is calibrated through a calibrated resistor network module, a calibrated ADC module, a calibrated DAC module and the external ADC module; wherein the calibrated DAC module is a calibrated first DAC module / second DAC module, and the calibrated ADC module is a calibrated first ADC module / second ADC module.

[0013] In one embodiment, the resistor network module includes more than two resistors, the first end of each resistor is grounded through a corresponding calibration switch, the second end of each resistor is connected to a high-end output line in the calibration bus through a corresponding calibration switch, and the second end of each resistor is also connected to a high-end measurement line in the calibration bus through a corresponding calibration switch.

[0014] In one embodiment, the digital board calibration device further includes a calibration switch, and the multimeter, the reference source module and the functional module are connected to the calibration bus through the corresponding calibration switches respectively.

[0015] In one embodiment, the digital board calibration device also includes a controller, which is connected to the calibration switch, the reference source module, the functional module and the industrial computer, and is used to control the on and off of the calibration switch and control the reference source module and the functional module to perform calibration according to instructions sent by the industrial computer.

[0016] In one embodiment, the first DAC module / the second DAC module includes a DAC chip, a first voltage change circuit and a current expansion circuit, the DAC chip is connected to the controller and the first voltage change circuit, the current expansion circuit is connected to the first voltage change circuit, and is connected to the high-end output line in the calibration bus through a corresponding calibration switch.

[0017] In one embodiment, the first ADC module / the second ADC module includes a second voltage change circuit and an ADC chip, the second voltage change circuit is connected to the high-end output line, the high-end measurement line and the low-end measurement line in the calibration bus through corresponding calibration switches respectively; the ADC chip is connected to the second voltage change circuit and the controller.

[0018] In one embodiment, the PE module includes a pin circuit, a first multiplexer and a second multiplexer, the pin circuit connects the controller, the first multiplexer and the second multiplexer, the first multiplexer is connected to the high-end measurement line in the calibration bus through a corresponding calibration switch, and the second multiplexer is connected to the low-end measurement line in the calibration bus through a corresponding calibration switch.

[0019] In one of the embodiments, the same group of monitoring output pins with buffers inside the pin circuit are respectively connected to the first multiplexer and the second multiplexer; the same group of monitoring output pins without buffers inside the pin circuit are respectively connected to the first multiplexer and the second multiplexer.

[0020] A second aspect of the present application provides a digital board calibration method, comprising:

[0021] The external ADC module is calibrated by the calibrated reference source module; wherein the external ADC module is connected to a pin circuit, the reference source module and the pin circuit are connected to a calibration bus, the calibration bus is used to connect a multimeter, and the reference source module is calibrated by the multimeter;

[0022] The pin circuit is calibrated by the calibrated external ADC module.

[0023] In one embodiment, calibrating the pin circuit by using a calibrated external ADC module includes:

[0024] Connecting the driving unit of the pin circuit to the external ADC module, controlling the output voltage of the driving unit of the pin circuit, measuring the voltage output by the driving unit through the calibrated external ADC module, and calibrating the driving unit of the pin circuit according to the measured voltage;

[0025] The driving unit of the pin circuit is connected to the comparing unit of the pin circuit, the calibrated output voltage of the driving unit is controlled, and the comparing unit of the pin circuit is calibrated according to the feedback voltage collected by the comparing unit of the pin circuit.

[0026] In one embodiment, calibrating the pin circuit by using a calibrated external ADC module includes:

[0027] Connecting the parameter measurement unit of the pin circuit to the external ADC module, controlling the parameter measurement unit of the pin circuit to output a voltage, measuring the voltage output by the parameter measurement unit through the calibrated external ADC module, and calibrating the output voltage of the parameter measurement unit of the pin circuit according to the measured voltage;

[0028] The parameter measurement unit of the pin circuit is connected to the external ADC module and the resistor network module, the parameter measurement unit of the pin circuit is controlled to output current, the current value is calculated according to the voltage measured by the calibrated external ADC module and the resistance value of the calibrated resistor network module, and the output current of the parameter measurement unit of the pin circuit is calibrated according to the current value; wherein the resistor network module is connected to the calibration bus and calibrated by the multimeter.

[0029] A third aspect of the present application provides a digital board calibration system, including a multimeter, an industrial computer and the above-mentioned digital board calibration device.

[0030] The above-mentioned digital board calibration device, method and system use a calibration bus to connect the reference source module and the functional module, and calibrate the reference source module through a multimeter. The uncalibrated functional module can be calibrated through the multimeter, the calibrated reference source module or the calibrated functional module, thereby reducing the number of times the multimeter needs to be used for calibration and improving the calibration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a structural block diagram of a digital board calibration device in one embodiment;

[0032] Figure 2 is a structural principle diagram of a digital board calibration device in one embodiment;

[0033] Figure 3 is a structural principle diagram of a digital board calibration device in another embodiment;

[0034] Figure 4 A schematic diagram of the structure of a first DAC module / a second DAC module in an embodiment;

[0035] Figure 5 is a structural schematic diagram of a first ADC module / a second ADC module in one embodiment;

[0036] Figure 6 is a structural schematic diagram of a PE module and an external ADC module in one embodiment;

[0037] Figure 7 is a schematic flow chart of a digital board calibration method in one embodiment;

[0038] Figure 8 FIG. 4 is a calibration principle diagram of a digital board calibration device in one embodiment. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] 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 belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0041] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0042] 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, wholes, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0043] In one embodiment, Figure 1 As shown, a digital board calibration device is provided, including a calibration bus 110, a reference source module 120 and a functional module 130. The calibration bus 110 is used to connect a multimeter 210; the reference source module 120 and the functional module 130 are both connected to the calibration bus 110. The reference source module 120 is calibrated by the multimeter 210, and the uncalibrated functional module 130 is calibrated by the multimeter 210, the calibrated reference source module 120 or the calibrated functional module 130.

[0044] The specific types of the reference source module 120 and the functional module 130 are not unique. The reference source module 120 may be a DAC module or a high-precision reference source chip, and the functional module 130 may include a resistor network module, a DAC module, an ADC module, and a PE module. The type of the calibration bus 110 is also not unique. In one embodiment, Figure 2 and Figure 3 As shown, the calibration bus 110 includes a high-end output line HF, a high-end measurement line HS, a low-end measurement line LS and a protection line GUARD. After the reference source module 120 is calibrated by the multimeter 210, the multimeter 210 or the reference source module 120 can be used to calibrate the functional module 130, or the calibrated functional module 130 can be used to calibrate the uncalibrated functional module 130. The specific calibration method can be adjusted according to actual needs, reducing the number of calibrations using the multimeter 210 and simplifying the wiring operation.

[0045] In one embodiment, the digital board calibration device further includes a calibration switch, and the multimeter 210, the reference source module 120 and the functional module 130 are connected to the calibration bus 110 through corresponding calibration switches. Figure 3 As shown, the reference source module 120 and the functional module 130 are connected to the calibration bus 110 through corresponding calibration switches, and the calibration bus 110 is also connected to the connector J1 through the corresponding calibration switch, and the connector J1 is used to connect the multimeter 210. Among them, the multimeter 210 can be a 6.5-digit or 8.5-digit multimeter, and the calibration switch can be a relay or other control switch.

[0046] Specifically, the high-end output line HF, the high-end measurement line HS, the low-end measurement line LS and the protection line GUARD of the calibration bus 110 are all connected to the corresponding pins of the multimeter 210 through the corresponding calibration switches. When the multimeter 210 is needed to measure, the calibration switch can be closed to connect the multimeter 210 to the circuit; when the multimeter 210 is not needed to measure, the calibration switch can be disconnected to prevent the calibration bus 110 from being connected to the multimeter 10, thereby avoiding the multimeter 210 from possibly affecting the calibration bus 110.

[0047] Furthermore, the digital board calibration device also includes a controller, which is connected to the calibration switch, the reference source module 120, the function module 130 and the industrial computer, and is used to control the on and off of the calibration switch according to the instructions sent by the industrial computer, and control the reference source module 120 and the function module 130 to calibrate. The industrial computer can be directly connected to the controller, or it can be indirectly connected to the controller through other processors. The controller can be an FPGA (Field Programmable Gate Array), a CPU (Central Processing Unit), an MCU (Micro Control Unit) or any other programmable logic device. In this embodiment, the controller is an FPGA (not shown in the figure), and the FPGA is set on the digital board. The digital calibration device can be set on the digital board, or it can be independently set on another board, or part of the hardware structure can be set on the digital board, and the remaining part of the hardware structure can be set on another structural board. The controller switches the corresponding calibration switch on and off according to the instruction sent by the industrial computer, thereby controlling the multimeter 210, the reference source module 120, the functional module 130 and the calibration bus 110 to be turned on or off, so as to facilitate different calibration operations. It can support multiple different paths to calibrate the functional module 130, which ensures that the tester has more choices and that there are backup plans or paths that can be used in case the preferred plan or path is not accurate enough, thereby greatly reducing the risk of board modification caused by unsuccessful hardware design.

[0048] The above-mentioned digital board calibration device, method and system use the calibration bus 110 to connect the reference source module 120 and the functional module 130, and calibrate the reference source module 110 through the multimeter 210. The uncalibrated functional module 130 can be calibrated through the multimeter 210, the calibrated reference source module 120 or the calibrated functional module 130, thereby reducing the number of times the multimeter 210 needs to be used for calibration and improving the calibration efficiency.

[0049] In one embodiment, Figure 2As shown, the reference source module 120 includes a first DAC module 122, the functional module 130 includes a resistor network module 131, a first ADC module 132 and a PE module 135, the first DAC module 122 and the resistor network module 131 are calibrated by a multimeter 210, and the first ADC module 132 is calibrated by the calibrated first DAC module 122. Specifically, the first DAC module 122 and the resistor network module 131 are first calibrated by an external multimeter 210, and then the first DAC module 122 is used to calibrate the first ADC module 132. The calibrated related modules are also used to calibrate the PE module 135 later. The calibration of the PE module 135 includes calibrating the driver unit Driver, the comparison unit, the parameter measurement unit (ParametricMeasurement Unit, PMU) and the active load unit inside the pin circuit. The voltage parameters that need to be calibrated for the driver unit are DVH / DVL / VTT, the voltage parameters that need to be calibrated for the comparison unit are VOH / VOL, the voltage parameters that need to be calibrated for the parameter measurement unit are FVMV, the current parameters that need to be calibrated for the parameter measurement unit are FIMI, the voltage parameters that need to be calibrated for the active load unit are VCOM, and the current parameters that need to be calibrated for the active load unit are IOH / IOL.

[0050] In one embodiment, Figure 3 As shown, the reference source module 120 includes a high-precision reference source chip 124, and the functional module 130 includes a resistor network module 131, a second ADC module 133, a second DAC module 134 and a PE module 135. The voltage accuracy of the high-precision reference source chip 124 is greater than the voltage accuracy of the second DAC module 134; the high-precision reference source chip 124 and the resistor network module 131 are calibrated by a multimeter 210, the second ADC module 133 is calibrated by the calibrated high-precision reference source chip 124, and the second DAC module 134 is calibrated by the calibrated second ADC module 133. Specifically, the high-precision reference source chip 124 can provide different voltage standard values. The high-precision reference source chip 124 and the resistor network module 131 are first calibrated by an external multimeter 210, and then the calibrated high-precision reference source chip 124 is used to calibrate the second ADC module 133, and the calibrated second ADC module 133 is used to calibrate the second DAC module 134. The calibrated related modules are also used to calibrate the PE module 135 later. The calibration of the PE module 135 may also include the calibration of the driving unit, the comparison unit, the parameter measurement unit and the active load unit inside the pin circuit. The calibrated high-precision reference source chip 124 is used as an accurate voltage reference for subsequent calibration, which has low noise, high accuracy, small temperature drift, small aging, and can maintain high accuracy for a long time, thus avoiding the frequent use of an external multimeter, and the accuracy is high enough.

[0051] Among them, the high-precision reference source chip 124 is a reference source chip that supports providing multiple reference voltage values, and the output voltage precision is high. Each voltage output pin of the high-precision reference source chip 124 is connected to the high-end measurement line HS in the calibration bus 110 through a corresponding calibration switch. Specifically, the voltage output pins of the high-precision reference source chip 124 include a +7V output pin, a +5V output pin, a +2.5V output pin, a +1.25V output pin, a -1.25V output pin, a -2.5V output pin, a -5V output pin, a -7V output pin and a 0V output pin, each voltage output pin is connected to the high-end measurement line HS through a calibration switch, and the 0V output pin is also connected to the low-end measurement line LS through a calibration switch, and is grounded through a resistor.

[0052] The above provides two types of reference source modules 120, and a specific reference source can be selected according to the actual usage scenario. For example, in a scenario where the accuracy requirement is not high (such as self-test), the first DAC module 122 can be used as the reference source; in a scenario where the accuracy requirement is high, a high-precision reference source chip 124 can be used as the reference source.

[0053] Furthermore, the digital board calibration device further includes an external ADC module 140, and the external ADC module 140 is connected to the PE module 135 and the calibration bus 110. The external ADC module 140 is calibrated by the calibrated DAC module, and the PE module is calibrated by the calibrated resistor network module 131, the calibrated ADC module, the calibrated DAC module and the external ADC module 140; wherein the calibrated DAC module is the calibrated first DAC module 122 / second DAC module 134, and the calibrated ADC module is the calibrated first ADC module 132 / second ADC module 133.

[0054] There is no unique way to calibrate the pin circuit in the PE module 135. Specifically, calibrating the pin circuit PE may include: connecting the drive unit of the pin circuit PE to the external ADC module 140, controlling the output voltage of the drive unit of the pin circuit PE, and measuring the voltage output by the drive unit through the calibrated external ADC module 140, and calibrating the drive unit of the pin circuit PE according to the measured voltage. Connecting the drive unit of the pin circuit PE to the comparison unit of the pin circuit PE, controlling the output voltage of the calibrated drive unit, and calibrating the comparison unit of the pin circuit according to the feedback voltage collected by the comparison unit of the pin circuit PE.

[0055] Calibrating the pin circuit PE may also include: connecting the parameter measurement unit of the pin circuit PE to the external ADC module 140, controlling the parameter measurement unit of the pin circuit PE to output a voltage, measuring the voltage output by the parameter measurement unit through the calibrated external ADC module 140, and calibrating the output voltage of the parameter measurement unit of the pin circuit PE according to the measured voltage. Connecting the parameter measurement unit of the pin circuit PE to the external ADC module 140 and the resistor network module 131, controlling the parameter measurement unit of the pin circuit PE to output a current, calculating a current value according to the voltage measured by the calibrated external ADC module 140 and the resistance value of the calibrated resistor network module 131, and calibrating the output current of the parameter measurement unit of the pin circuit PE according to the current value.

[0056] The resistor network module 131 is a high-precision, low-temperature drift resistor network module, which is used to provide accurate resistance when testing the current in the subsequent test, so as to obtain the current value flowing through the resistor by means of voltage / resistance. It can be understood that the structure of the resistor network module 131 is not unique. In one embodiment, the resistor network module 131 includes more than two resistors, and the first end of each resistor is grounded through a corresponding calibration switch, and can also be connected to the low-end measurement line LS through a corresponding calibration switch. The second end of each resistor is connected to the high-end output line HF in the calibration bus 110 through a corresponding calibration switch, and the second end of each resistor is also connected to the high-end measurement line HS in the calibration bus 110 through a corresponding calibration switch. Among them, the number of resistors can be two or more, and the resistance values ​​of some resistors can be different, and the resistance values ​​of some resistors can be the same; or the resistance values ​​of each resistor can be different. In this embodiment, each resistor in the resistor network module 131 can be grounded by controlling the relevant calibration switch, so that it is convenient to directly use the ground + resistance method as a load, and the DAC + resistance method can be used as a load, which simplifies the load circuit.

[0057] The first DAC module 122 / the second DAC module 134 is mainly used to provide a reference during current testing and a voltage source of general accuracy during self-testing. The internal structure of the DAC module is not unique, and may specifically include a DAC chip and a DAC analog front-end circuit. Considering that the actual required voltage range is greater than the output voltage range of the DAC chip, and the output current of the DAC chip is limited, the DAC analog front-end circuit may include a voltage change circuit and a current expansion circuit, and a voltage change circuit is added behind the DAC chip to perform voltage conversion, and then the current expansion circuit is connected to increase the output current.

[0058] In one embodiment, Figure 4As shown, the first DAC module 122 / the second DAC module 134 includes a DAC chip U42, a first voltage variation circuit 11 and a current expansion circuit 12, and may also include related peripheral circuits connected to the DAC chip U42. The DAC chip U42 is connected to the controller and the first voltage variation circuit 11, and the current expansion circuit 12 is connected to the first voltage variation circuit 11, and is connected to the high-end output line HF in the calibration bus 110 through a corresponding calibration switch. Specifically, the first voltage variation circuit 11 includes a resistor R197, a resistor R200, a resistor R201, a resistor R207, a capacitor C121, a capacitor C4904, an operational amplifier U41A and an operational amplifier U41B, and the current expansion circuit 12 may include a resistor R202, a resistor R203, a resistor R204, a capacitor C118 and a buffer operational amplifier U43. The first end of the resistor R197 is connected to the VREF pin of the DAC chip U42, and the second end of the resistor R197 is connected to the non-inverting input terminal of the operational amplifier U41A, and is grounded through the resistor R200. The inverting input terminal of the operational amplifier U41A is connected to the output terminal of the operational amplifier U41A, and the output terminal of the operational amplifier U41A is connected to the first terminal of the resistor R201, and the second terminal of the resistor R201 is connected to the inverting input terminal of the operational amplifier U41B, the first terminal of the resistor R202, and the first terminal of the capacitor C118. The first terminal of the capacitor C121 is connected to the VREF pin of the DAC chip U42, and the second terminal of the capacitor C121 is grounded. The first terminal of the resistor R207 is connected to the VOUT pin of the DAC chip U42, and the second terminal of the resistor R207 is connected to the non-inverting input terminal of the operational amplifier U41B and is grounded through the capacitor C4904. The second terminal of the resistor R202 is connected to the first terminal of the resistor R203, and the second terminal of the resistor R203 is connected to the second terminal of the capacitor C118 and the output terminal of the buffer operational amplifier U43. The output end of the operational amplifier U41B is connected to the inverting input end of the buffer operational amplifier U43 through the resistor R204, the non-inverting input end of the buffer operational amplifier U43 is connected to the power access end, and the output end of the buffer operational amplifier U43 is connected to the high-end output line HF in the calibration bus 110 through the corresponding calibration switch.

[0059] Further, the first DAC module 122 / the second DAC module 134 may also include a first control module 13, the first control module 13 is connected to the ground pin of the DAC chip U42, the low-end measurement line LS and the controller, and by switching the on and off of the first control module 13, it is possible to control whether the ground pin of the DAC chip U42 is connected to the low-end measurement line LS. Specifically, the first control module 13 includes a control switch K26, a resistor R214 and a resistor R1944, and the control switch K26 may be an optocoupler or other switch. One end of the control unit of the control switch K26 is connected to the controller, and the other end is connected to the power supply access end through the resistor R214. One end of the controlled unit of the control switch K26 is connected to the ground pin of the DAC chip U42 through the resistor R1944, and the other end is grounded.

[0060] In addition, the first DAC module 122 / the second DAC module 134 may also include a filter capacitor component, which is connected to the power supply terminal of the relevant operational amplifier and is grounded, and is used to filter the power supply connected to the power supply terminal of the operational amplifier. Specifically, the filter capacitor component may include one or more filter capacitors, such as capacitor C111, capacitor C112, capacitor C113, capacitor C114, capacitor C108, capacitor C109, capacitor C110 and capacitor C115, and the power supply terminal of each operational amplifier in the DAC module is connected to the same external power supply, and each filter capacitor has one end connected to the power supply terminal of the operational amplifier and the other end is grounded.

[0061] The first ADC module 132 / the second ADC module 133 is mainly used for current testing. By measuring the voltage across the corresponding resistor in the resistor network module 131 and dividing it by the resistance value of the resistor, the current value flowing through the resistor can be obtained. The internal structure of the ADC module is not unique, and may specifically include an ADC chip and an ADC analog front-end circuit. The ADC analog front-end circuit may specifically include a voltage change circuit to perform voltage conversion on the voltage output by the ADC chip. The voltage change circuit is connected to the high-end output line HF and the high-end measurement line HS respectively through corresponding calibration switches, and the connection relationship between the ADC chip and the calibration bus 110 can be changed by switching the calibration switch on and off.

[0062] In one embodiment, Figure 5 As shown, the first ADC module 132 / the second ADC module 133 includes a second voltage variation circuit and an ADC chip U40, and may also include related peripheral circuits connected to the ADC chip U40. The second voltage variation circuit is connected to the high-end output line HF, the high-end measurement line HS, and the low-end measurement line LS in the calibration bus through corresponding calibration switches; the ADC chip U40 is connected to the second voltage variation circuit and the controller.

[0063] Specifically, the second voltage variation circuit may include a follower circuit 21, a filter circuit 22, a difference circuit 23, a signal amplifier circuit 24, and a voltage processing circuit 25. The first input port of the follower circuit 21 is connected to the high-end output line HF through a corresponding calibration switch, and is also connected to the high-end measurement line HS through a corresponding calibration switch. The second input port of the follower circuit 21 is connected to the low-end measurement line LS through a corresponding calibration switch. The voltage signal connected to the first input port of the follower circuit 21 can be changed by switching the calibration switch. The two voltages VP and VM output by the calibration bus 110 are respectively transmitted to the filter circuit 22 through the follower circuit 21 for low-pass filtering, and then the difference circuit 23 makes a difference on the two received voltages, and transmits the signal VP-VM to the signal amplifier circuit 24. The signal amplifier circuit 24 amplifies the signal VP-VM, for example, after integer multiple amplification, the amplified signal is transmitted to the voltage processing circuit 25. The voltage processing circuit 25 performs linear amplification processing on the received signal, for example, multiplies the signal by an integer multiple and then adds a set voltage. The final voltage is transmitted to the ADC chip U40, and then transmitted to the controller after analog-to-digital conversion by the ADC chip U40.

[0064] Specifically, the follower circuit 21 includes an operational amplifier U44A, an operational amplifier U44B, a resistor R206, a resistor R216, a resistor R208, and a resistor R210. The in-phase input terminal of the operational amplifier U44A is connected to the first end of the resistor R206, and the second end of the resistor R206 is connected to the high-end output line HF through a corresponding calibration switch, and is also connected to the high-end measurement line HS through a corresponding calibration switch. The inverting input terminal of the operational amplifier U44A is connected to the output terminal of the operational amplifier U44A, and the output terminal of the operational amplifier U44A is connected to the filter circuit 22. The in-phase input terminal of the operational amplifier U44B is connected to the first end of the resistor R216, and the second end of the resistor R216 is connected to the low-end measurement line LS through a corresponding calibration switch. The inverting input terminal of the operational amplifier U44B is connected to the output terminal of the operational amplifier U44B, and the output terminal of the operational amplifier U44B is connected to the filter circuit 22.

[0065] The filter circuit 22 may specifically include a resistor R260, a resistor R210, a capacitor C122 and a capacitor C123, and the difference circuit 23 may specifically include a differential amplifier U46. The first end of the resistor R260 is connected to the output end of the operational amplifier U44A, the second end of the resistor R260 is connected to the non-inverting input end of the differential amplifier U46, and is grounded through the capacitor C122. The first end of the resistor R210 is connected to the output end of the operational amplifier U44B, the second end of the resistor R210 is connected to the inverting input end of the differential amplifier U46, and is grounded through the capacitor C123. The second voltage variation circuit may also include a resistor R211, and the output end of the differential amplifier U46 is connected to the signal amplifier circuit 24 through the differential amplifier U46.

[0066] The signal amplification circuit 24 may specifically include an operational amplifier 45A, a resistor R2172, a resistor R2169, a resistor R2170, a resistor R2171, a resistor R216, and a resistor R217. The non-inverting input terminal of the operational amplifier 45A is connected to the output terminal of the differential amplifier U46 through the resistor R211, and the inverting input terminal of the operational amplifier 45A is grounded through the resistor R2172. The resistor R216 and the resistor R217 are connected in series, and the other end of the resistor R216 is connected to the non-inverting input terminal of the operational amplifier 45A, and the other end of the resistor R217 is grounded. The resistor R2169, the resistor R2170, and the resistor R2171 are connected in series in sequence, and the other end of the resistor R2169 is connected to the inverting input terminal of the operational amplifier 45A, and the other end of the resistor R2171 is connected to the output terminal of the operational amplifier 45A, and the output terminal of the operational amplifier 45A is connected to the voltage processing circuit 25.

[0067] The voltage processing circuit 25 may specifically include an operational amplifier 45B, a resistor R212, a resistor R215, a resistor R205, a resistor R199, a capacitor C120 and a capacitor C116. The non-inverting input terminal of the operational amplifier 45B is connected to the output terminal of the operational amplifier 45A through the resistor R212, and is connected to the reference voltage terminal through the resistor R215. The resistor R205 and the capacitor C120 are connected in parallel, and one end is connected to the inverting input terminal of the operational amplifier 45B, and the other end is connected to the output terminal of the operational amplifier 45B. The output terminal of the operational amplifier 45B is connected to the first end of the resistor R199, and the second end of the resistor R199 is connected to the ADC chip U40 through the peripheral circuit. The second end of the resistor R199 is also grounded through the capacitor C116.

[0068] Further, the first ADC module 132 / the second ADC module 133 may also include a second control module 26, the second control module 26 is connected to the ground pin of the ADC chip U40, the low-end measurement line LS and the controller, and by switching the on and off of the second control module 26, it is possible to control whether the ground pin of the ADC chip U40 is connected to the low-end measurement line LS. Specifically, the second control module 26 includes a control switch K31, a resistor R936 and a resistor R1945, and the control switch K31 may be an optocoupler or other switch. One end of the control unit of the control switch K31 is connected to the controller, and the other end is connected to the power supply access end through the resistor R936. One end of the controlled unit of the control switch K31 is connected to the ground pin of the ADC chip U40 through the resistor R1945, and the other end is grounded.

[0069] The PE module 135 is mainly used to realize the output and measurement functions of DC parameters so as to detect the DC parameters of other chips. For example, it can output voltage to the load and then measure the output current to know the power consumption of the load. Figure 2 As shown, the PE module 135 can provide only one monitoring output (the pin circuit has a buffer inside); Figure 3 As shown, the PE module 135 may also provide monitoring output and raw output (without a buffer inside the pin circuit) so that they can be compared to improve accuracy.

[0070] In one embodiment, Figure 6 As shown, the PE module 135 includes a pin circuit PE, a first multiplexer M1 and a second multiplexer M2. The pin circuit PE is connected to the controller, the first multiplexer M1 and the second multiplexer M2. The first multiplexer M1 is connected to the high-end measurement line HS in the calibration bus 110 through a corresponding calibration switch, and the second multiplexer M2 is connected to the low-end measurement line LS in the calibration bus 110 through a corresponding calibration switch. In this embodiment, the PE module 135 provides monitoring output and original output. The same group of monitoring output pins with buffers inside the pin circuit PE are respectively connected to the first multiplexer M1 and the second multiplexer M2; the same group of monitoring output pins without buffers inside the pin circuit PE are respectively connected to the first multiplexer M1 and the second multiplexer M2. Specifically, the pin circuit PE has two groups of monitoring outputs with internal buffers, namely MON_0 / MON_REF_0 and MON_1 / MON_REF_1, and the pin circuit PE has one group of monitoring outputs without internal buffers: EXT_SNS_HI / EXT_SNS_LO. One of the monitoring output pins in the same group is connected to the input end of the first multiplexer M1, and the other pin is connected to the input end of the second multiplexer M2. The output end of the first multiplexer M1 is connected to the high-end measurement line HS through the corresponding calibration switch, and the output end of the second multiplexer M2 is connected to the low-end measurement line LS through the corresponding calibration switch.

[0071] Further, the external ADC module 140 includes an external ADC chip and a follower, the external ADC chip is connected to the controller, and is respectively connected to the output end of the first multiplexer M1 and the output end of the second multiplexer M2 through the corresponding follower. In addition, the external ADC chip can also be connected to the calibration bus 110 through the corresponding follower.

[0072] In one embodiment, a digital board calibration method is also provided, which is applied to the digital board calibration device described above. Figure 7 As shown, the calibration method includes:

[0073] Step S100: Calibrate the external ADC module through the calibrated reference source module; wherein the external ADC module is connected to the pin circuit, the reference source module and the pin circuit are connected to the calibration bus, the calibration bus is used to connect the multimeter, and the reference source module is calibrated through the multimeter.

[0074] Step S200: Calibrate the pin circuit through the calibrated external ADC module.

[0075] In one embodiment, step S200 includes: connecting the driving unit of the pin circuit to an external ADC module, controlling the output voltage of the driving unit of the pin circuit, measuring the voltage output by the driving unit through a calibrated external ADC module, and calibrating the driving unit of the pin circuit according to the measured voltage. Connecting the driving unit of the pin circuit to a comparison unit of the pin circuit, controlling the output voltage of the calibrated driving unit, and calibrating the comparison unit of the pin circuit according to the feedback voltage collected by the comparison unit of the pin circuit.

[0076] In one embodiment, step S200 includes: connecting the parameter measurement unit of the pin circuit to an external ADC module, controlling the parameter measurement unit of the pin circuit to output a voltage, and measuring the voltage output by the parameter measurement unit through a calibrated external ADC module, and calibrating the output voltage of the parameter measurement unit of the pin circuit according to the measured voltage. Connecting the parameter measurement unit of the pin circuit to an external ADC module and a resistor network module, controlling the parameter measurement unit of the pin circuit to output a current, calculating the current value according to the voltage measured by the calibrated external ADC module and the resistance value of the calibrated resistor network module, and calibrating the output current of the parameter measurement unit of the pin circuit according to the current value; wherein the resistor network module is connected to a calibration bus and calibrated by a multimeter.

[0077] It can be understood that the specific implementation of the above-mentioned digital board calibration method has been explained in detail in the digital board calibration device, and will not be repeated here.

[0078] by Figure 3 For example, the digital plate calibration device Figure 8 As shown, the calibration steps of the digital board calibration device are as follows:

[0079] 1. Use a multimeter four-wire method to calibrate the high-precision reference source chip 124 and the resistor network module 131.

[0080] Calibrate the reference source: By closing the calibration switch, connect the multimeter to the calibration bus. The multimeter is connected to the industrial computer through the GPIB interface, so that the industrial computer can normally control and read the multimeter data. Then close the calibration switch of the first reference source of the high-precision reference source chip 124, and the industrial computer reads the voltage value of the multimeter and records it as the voltage value of this reference source. Then turn off the switch of the first reference source, and the calibration of the first reference source is now complete. Then repeat the above steps to calibrate the voltages of subsequent reference sources of the high-precision reference source chip 124 in turn.

[0081] Calibrate the resistor: By closing the calibration switch, connect the multimeter to the calibration bus, and the multimeter is connected to the industrial computer through the GPIB interface, so that the industrial computer can normally control and read the multimeter data. Then close the calibration switch of the first resistor in the resistor network module 131, and the industrial computer reads the resistance value of the multimeter and records it as the value of this resistor. Then open the switch of the first resistor, and the calibration of the first resistor is completed. Then repeat the above steps to calibrate the resistance values ​​of subsequent resistors in the resistor network module 131 in sequence.

[0082] 2. Calibrate the ADC module using a reference source.

[0083] By closing the calibration switch, the high-precision reference source chip 124 and the ADC module are connected together. The industrial computer controls the output voltage of the high-precision reference source chip 124, and then measures this voltage through the ADC module. Then, linear fitting is used to calibrate the curve of the ADC module. After calibration, all calibration switches are disconnected.

[0084] 3. Calibrate the DAC module using the ADC module.

[0085] By closing the calibration switch, the ADC module and the DAC module are connected together. The industrial computer controls the output voltage of the DAC module, and then measures this voltage through the ADC module. Then use linear fitting to calibrate the curve of the DAC module. After calibration, all calibration switches are disconnected.

[0086] 4. Calibrate the external ADC module 140 of the PE module 135 using a reference source.

[0087] By closing the calibration switch, the high-precision reference source chip 124 and the external ADC module 140 are connected together. The industrial computer controls the output voltage of the high-precision reference source chip 124, and then measures the voltage through the external ADC module 140. Then, a linear fit is used to calibrate the curve of the external ADC module 140. After the calibration is completed, all the calibration switches are disconnected.

[0088] 5. Use the external ADC module 140 to calibrate the DVH, DVL and VTT voltages of the pin circuit PE.

[0089] By closing the calibration switch, the driving unit of the pin circuit PE is connected to the external ADC module 140. The industrial computer controls the pin circuit PE to output the DVH / DVL / VTT voltage, and then measures the voltage through the external ADC module 140. Then, the corresponding fitting algorithm is used to calibrate the DVH / DVL / VTT curve. After the calibration, all the calibration switches are turned off.

[0090] 6. Use the DVH voltage of pin circuit PE to calibrate the VOH / VOL voltage of pin circuit PE.

[0091] By closing the internal switch of the pin circuit PE, the driving unit of the pin circuit PE and the comparison unit of the pin circuit PE are connected together. The industrial computer controls the pin circuit PE to output the VIH voltage, then collects the voltage fed back by VOH / VOL, and then uses the corresponding fitting algorithm to calibrate the VOH / VOL curve. After calibration, all calibration switches are disconnected.

[0092] 7. Use the external ADC module 140 to calibrate the VCOM voltage of the pin circuit PE.

[0093] By closing the calibration switch, the active load unit of the pin circuit PE is connected to the external ADC module 140, the industrial computer controls the pin circuit PE to output the VCOM voltage, the voltage is measured by the external ADC module 140, and then the corresponding fitting algorithm is used to calibrate the VCOM curve. After the calibration, all the calibration switches are opened.

[0094] 8. Use the external ADC module 140 to calibrate the FVMV voltage of the pin circuit PE and the FIMI current.

[0095] Calibrate FVMV voltage: By closing the calibration switch, connect the external ADC module 140 and the parameter measurement unit of the pin circuit PE together, the industrial computer controls the parameter measurement unit of the pin circuit PE to output voltage (operating in FVMV mode), and the voltage is measured by the external ADC module 140, and then the corresponding fitting algorithm is used to calibrate the FVMV curve. After calibration, all calibration switches are disconnected.

[0096] Calibrate FIMI current: By closing the calibration switch, connect the external ADC module 140, the resistor network module 131 and the parameter measurement unit of the pin circuit PE together, the industrial computer controls the pin circuit PE to output current (working in FIMI mode), and then measures this voltage through the external ADC module 140, and then divides it by the resistance value connected to the resistor network module 131 to obtain the corresponding current value, and then uses the corresponding fitting algorithm to calibrate the FIMI curve. After calibration, all calibration switches are disconnected.

[0097] 9. Calibrate the IOH / IOL current of pin circuit PE using the FVMI of pin circuit PE.

[0098] By closing the switch inside the pin circuit PE, the parameter measurement unit of the pin circuit PE is connected to the active load unit of the pin circuit PE. The industrial computer controls the parameter measurement unit of the pin circuit PE to work in the FVMI mode, sets the IOH / IOL current of the active load unit, measures this current value through the parameter measurement unit, and then uses the corresponding fitting algorithm to calibrate the IOH / IOL curve.

[0099] In one embodiment, a digital board calibration system is further provided, comprising a multimeter, an industrial computer and the digital board calibration device described above.

[0100] The above-mentioned digital board calibration device, method and system reserve multiple sets of calibration schemes and paths, thereby ensuring that if a set of schemes or paths is not suitable, there are backup schemes or paths to choose from. At the same time, different schemes and paths can be compared to select a more accurate scheme or path, which also reduces the probability of changing the board and reduces manufacturing costs. While being able to provide higher voltage accuracy, it also retains a more efficient DAC reference source during self-calibration. The voltage reference source uses a high-precision external reference source, which is more accurate than the general use of DAC output as a reference source, with smaller temperature drift and smaller ripple. However, because the voltage reference source is limited and expensive, in scenarios such as self-test where accuracy requirements are not high, DAC can be used as a reference source, which will be more efficient.

[0101] The above-mentioned digital plate calibration device, method and system have several advantages:

[0102] 1. High precision. When a high-precision external reference source is used as the voltage reference source, the accuracy is higher, the temperature drift is smaller, and the ripple is smaller than when the DAC output is generally used as the reference source.

[0103] 2. Higher flexibility. Multiple solutions or paths are reserved during calibration. For example, when calibrating a DAC, you can use an ADC for calibration or an external multimeter for calibration. The implementation method is to switch through a switch network. Because all modules are interconnected through the calibration bus, they can be interconnected two by two through the calibration bus, so there are multiple combinations to ensure that if one solution or path is not suitable, there is a backup solution or path. At the same time, different solutions and paths can be compared to select a more accurate solution or path.

[0104] 3. Lower cost. Because multiple solutions or paths are reserved, the risk of board modification is reduced, thereby reducing the cost of the entire board.

[0105] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0106] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A digital board calibration device, characterized in that: include: Calibration bus, used to connect the multimeter; A reference source module connected to the calibration bus; A functional module connected to the calibration bus, wherein the number of the functional modules is more than two; The reference source module is calibrated by the multimeter, and the uncalibrated functional module is calibrated by the multimeter, the calibrated reference source module or the calibrated functional module.

2. The digital board calibration device according to claim 1, characterized in that: The reference source module includes a first DAC module, the functional module includes a resistor network module, a first ADC module and a PE module, the first DAC module and the resistor network module are calibrated by the multimeter, and the first ADC module is calibrated by the calibrated first DAC module.

3. The digital board calibration device according to claim 1, characterized in that: The reference source module includes a high-precision reference source chip, the functional module includes a resistor network module, a second ADC module, a second DAC module and a PE module, the voltage accuracy of the high-precision reference source chip is greater than the voltage accuracy of the second DAC module; the high-precision reference source chip and the resistor network module are calibrated by the multimeter, the second ADC module is calibrated by the calibrated high-precision reference source chip, and the second DAC module is calibrated by the calibrated second ADC module.

4. The digital plate calibration device according to claim 2 or 3, characterized in that: Also includes: An external ADC module, the external ADC module is connected to the PE module and the calibration bus; the external ADC module is calibrated by a calibrated DAC module, and the PE module is calibrated by a calibrated resistor network module, a calibrated ADC module, a calibrated DAC module and the external ADC module; wherein the calibrated DAC module is a calibrated first DAC module / second DAC module, and the calibrated ADC module is a calibrated first ADC module / second ADC module.

5. The digital plate calibration device according to claim 2 or 3, characterized in that: The resistor network module includes more than two resistors, the first end of each resistor is grounded through a corresponding calibration switch, the second end of each resistor is connected to a high-end output line in the calibration bus through a corresponding calibration switch, and the second end of each resistor is also connected to a high-end measurement line in the calibration bus through a corresponding calibration switch.

6. The digital board calibration device according to claim 2 or 3, characterized in that: It also includes a calibration switch, and the multimeter, the reference source module and the functional module are connected to the calibration bus through the corresponding calibration switches.

7. The digital board calibration device according to claim 6, characterized in that: It also includes a controller, which is connected to the calibration switch, the reference source module, the functional module and the industrial computer, and is used to control the on and off of the calibration switch and control the reference source module and the functional module to calibrate according to instructions sent by the industrial computer.

8. The digital board calibration device according to claim 7, characterized in that: The first DAC module / the second DAC module includes a DAC chip, a first voltage change circuit and a current expansion circuit. The DAC chip is connected to the controller and the first voltage change circuit. The current expansion circuit is connected to the first voltage change circuit and is connected to the high-end output line in the calibration bus through a corresponding calibration switch.

9. The digital board calibration device according to claim 7, characterized in that: The first ADC module / the second ADC module includes a second voltage change circuit and an ADC chip, the second voltage change circuit is connected to the high-end output line, the high-end measurement line and the low-end measurement line in the calibration bus through corresponding calibration switches respectively; the ADC chip is connected to the second voltage change circuit and the controller.

10. The digital board calibration device according to claim 7, characterized in that: The PE module includes a pin circuit, a first multiplexer and a second multiplexer, the pin circuit connects the controller, the first multiplexer and the second multiplexer, the first multiplexer is connected to the high-end measurement line in the calibration bus through a corresponding calibration switch, and the second multiplexer is connected to the low-end measurement line in the calibration bus through a corresponding calibration switch.

11. The digital board calibration device according to claim 10, characterized in that: The same group of monitoring output pins with buffers inside the pin circuit are respectively connected to the first multiplexer and the second multiplexer; the same group of monitoring output pins without buffers inside the pin circuit are respectively connected to the first multiplexer and the second multiplexer.

12. A digital board calibration method, characterized in that: include: The external ADC module is calibrated by the calibrated reference source module; wherein the external ADC module is connected to a pin circuit, the reference source module and the pin circuit are connected to a calibration bus, the calibration bus is used to connect a multimeter, and the reference source module is calibrated by the multimeter; The pin circuit is calibrated by the calibrated external ADC module.

13. The digital board calibration method according to claim 12, characterized in that: The step of calibrating the pin circuit by using the calibrated external ADC module comprises: Connecting the driving unit of the pin circuit to the external ADC module, controlling the output voltage of the driving unit of the pin circuit, measuring the voltage output by the driving unit through the calibrated external ADC module, and calibrating the driving unit of the pin circuit according to the measured voltage; The driving unit of the pin circuit is connected to the comparing unit of the pin circuit, the calibrated output voltage of the driving unit is controlled, and the comparing unit of the pin circuit is calibrated according to the feedback voltage collected by the comparing unit of the pin circuit.

14. The digital board calibration method according to claim 12, characterized in that: The step of calibrating the pin circuit by using the calibrated external ADC module comprises: Connecting the parameter measurement unit of the pin circuit to the external ADC module, controlling the parameter measurement unit of the pin circuit to output a voltage, measuring the voltage output by the parameter measurement unit through the calibrated external ADC module, and calibrating the output voltage of the parameter measurement unit of the pin circuit according to the measured voltage; The parameter measurement unit of the pin circuit is connected to the external ADC module and the resistor network module, the parameter measurement unit of the pin circuit is controlled to output current, the current value is calculated according to the voltage measured by the calibrated external ADC module and the resistance value of the calibrated resistor network module, and the output current of the parameter measurement unit of the pin circuit is calibrated according to the current value; wherein the resistor network module is connected to the calibration bus and calibrated by the multimeter.

15. A digital board calibration system, characterized in that: The invention comprises a multimeter, an industrial computer and a digital board calibration device as claimed in any one of claims 1 to 11.

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