Multi-input impedance and multi-range selection time measuring device and testing machine

Abstract

The utility model relates to the field of chip testing, in particular to a multi-input impedance and multi-range selection time measuring device and a testing machine. The device comprises a front-end conditioning circuit and a rear-end measuring circuit connected with the front-end conditioning circuit, the front-end conditioning circuit comprises an input impedance selection circuit which comprises a plurality of input impedances and is used for receiving an analog signal to be detected and a plurality of first control signals and selecting access of any input impedance according to the plurality of first control signals; the range selection circuit comprises a plurality of range circuits and is used for receiving the second control signal and selecting access of any range circuit according to the second control signal; and the signal conversion circuit is used for receiving the to-be-measured analog signals passing through the input impedance selection circuit and the range selection circuit and converting the to-be-measured analog signals into to-be-measured digital signals. The requirements of different types of analog signals to be measured on input impedance can be met, and a proper measuring range can be selected according to the analog signals to be measured with different voltage amplitudes.

Description

Technical Field

[0001] The present application relates to the field of chip testing, and in particular to a time measurement device and a tester with multiple input impedances and multiple range selections. Background Art

[0002] Time measurement devices are mainly used in semiconductor automatic test equipment products to test the time parameters of high-speed signals, including but not limited to period, rising edge, falling edge, high pulse width, low pulse width, delay, duty cycle, etc.

[0003] In the existing technical solution, the time measurement device, the analog signal to be measured is converted into a digital signal by the front-end conditioning circuit for signal conditioning, and then sent to the back-end measurement circuit for measuring the time parameters. Among them, the front-end conditioning circuit is generally composed of a single parameter filter circuit and a comparator. However, in this case, the input impedance of the circuit is fixed, and the amplitude range of the analog signal to be measured that can be detected is also fixed. This circuit can only measure a certain type and amplitude of the analog signal to be measured, so the time measurement device with a single input impedance is not enough to meet the measurement requirements of different types of analog signals to be measured. At the same time, since the gain of the front-end conditioning circuit is fixed, when the amplitude range of the analog signal to be measured is relatively large, the analog signal to be measured with a larger amplitude will exceed the maximum amplitude requirement of the comparator input due to insufficient attenuation, and the analog signal to be measured with a smaller amplitude will be too attenuated, resulting in a very small signal voltage input to the comparator, which greatly affects the measurement accuracy of the time parameters. Utility Model Content

[0004] Based on this, it is necessary to provide a time measurement device and a test machine with multiple input impedances and multiple range selections to address the above technical issues.

[0005] In a first aspect, an embodiment of the present application provides a time measurement device with multiple input impedances and multiple range selections, the device comprising a front-end conditioning circuit and a back-end measurement circuit connected to the front-end conditioning circuit; wherein the front-end conditioning circuit comprises:

[0006] An input impedance selection circuit, comprising a plurality of input impedances, for receiving an analog signal to be measured and a plurality of first control signals, and selecting access to any input impedance according to the plurality of first control signals;

[0007] A range selection circuit, connected to the input impedance selection circuit, including a plurality of range circuits, for receiving a second control signal and selecting access to any range circuit according to the second control signal;

[0008] The signal conversion circuit is connected to the range selection circuit and is used for receiving the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, and converting the analog signal to be measured into a digital signal to be measured.

[0009] In one embodiment, the input impedance selection circuit further includes:

[0010] A plurality of input impedance selection switches are connected to the plurality of input impedances in a one-to-one correspondence, and are used to receive the first control signal and control the access of corresponding input impedances according to the first control signal.

[0011] In one embodiment, the range selection circuit further includes:

[0012] A plurality of range selection switches are connected to the plurality of range circuits in a one-to-one correspondence, and are used to receive the second control signal and control access to the corresponding range circuits according to the second control signal.

[0013] In one embodiment, the range circuit includes a first resistor and a second resistor;

[0014] The first resistor is connected between the range selection switch and the signal conversion circuit; the second resistor is connected between the signal conversion circuit and a reference ground.

[0015] In one embodiment, the sum of the resistance values ​​of the first resistor and the second resistor included in each of the range circuits is equal, and their ratios are not equal.

[0016] In one embodiment, the range circuit further includes a first capacitor and a second capacitor;

[0017] The first capacitor is connected in parallel with the first resistor, and the second capacitor is connected in parallel with the second resistor.

[0018] In one embodiment, the signal conversion circuit includes:

[0019] A buffer, connected to the range selection circuit, for buffering the analog signal to be measured that passes through the input impedance selection circuit and the range selection circuit;

[0020] The comparison unit is connected to the buffer and is used for receiving the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, comparing the analog signal with the high and low thresholds, and outputting the digital signal to be measured.

[0021] In one embodiment, the comparison unit comprises:

[0022] A first comparator, used for receiving the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, comparing the analog signal with a high threshold, and outputting a first digital signal to be measured;

[0023] The second comparator is used to receive the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, compare it with the low threshold value, and output a second digital signal to be measured.

[0024] In one embodiment, the back-end measurement circuit includes:

[0025] A processor is connected to the first comparator and the second comparator, and is used to calculate the time parameter of the analog signal to be measured according to the first digital signal to be measured and the second digital signal to be measured.

[0026] In a second aspect, an embodiment of the present application provides a testing machine, comprising a time measurement device with multiple input impedances and multiple range selections as described in the first aspect.

[0027] Compared with the prior art, the present technical solution utilizes an input impedance selection circuit to select the access of any input impedance to meet the input impedance requirements of different types of analog signals to be measured; utilizes a range selection circuit to select the access of any range circuit, and can select a suitable range for analog signals to be measured with different voltage amplitudes, thereby expanding the voltage amplitude range of the analog signal to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of a time measurement device with multiple input impedances and multiple range options in one embodiment of the present application;

[0029] Figure 2 This is a schematic diagram of the specific structure of a time measurement device with multiple input impedances and multiple range options in one embodiment of the present application.

[0030] Among them, 10, front-end conditioning circuit; 20, back-end measurement circuit; 110, input impedance selection circuit; 120, range selection circuit; 130, signal conversion circuit. DETAILED DESCRIPTION

[0031] 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.

[0032] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0033] Reference to "embodiments" in this application means that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in multiple embodiments of the application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0034] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0035] like Figure 1As shown, an embodiment of the present application proposes a time measurement device with multiple input impedances and multiple range selections, the device comprising a front-end conditioning circuit 10 and a back-end measurement circuit 20 connected to the front-end conditioning circuit 10; wherein the front-end conditioning circuit 10 comprises: an input impedance selection circuit 110, comprising multiple input impedances, for receiving an analog signal to be measured and multiple first control signals, and selecting access to any input impedance according to the multiple first control signals; a range selection circuit 120, connected to the input impedance selection circuit 110, comprising multiple range circuits, for receiving a second control signal, and selecting access to any range circuit according to the second control signal; a signal conversion circuit 130, connected to the range selection circuit 120, for receiving the analog signal to be measured passing through the input impedance selection circuit 110 and the range selection circuit 120, and converting it into a digital signal to be measured.

[0036] In this embodiment, appropriate input impedance can be selected according to different characteristics of the analog signal to be measured to meet the requirements of different types of analog signals to be measured for input impedance. For example, low input impedance is used to absorb signal reflection when the analog signal to be measured is a high-speed signal; high input impedance is used to deal with some analog signals to be measured with poor driving capabilities, and to avoid affecting the measurement accuracy due to the voltage difference introduced by the wiring current.

[0037] In addition, this embodiment adopts multiple range circuits, and can select appropriate range circuits for analog signals to be measured with different voltage amplitudes, thereby expanding the voltage amplitude range of the analog signal to be measured and overcoming the disadvantages that the amplitude of the analog signal to be measured is too large and exceeds the input range requirement, and the amplitude of the analog signal to be measured is too small and affects the measurement accuracy.

[0038] The following uses three different input impedances and three different range circuits as examples to explain the time measurement device in detail. Figure 2 It should be noted that the time measurement device can also be a circuit with other numbers of input impedance and range.

[0039] like Figure 2As shown, the input impedance selection circuit 110 includes two input impedances and three input impedance selection switches (K1, K2, K6). Among them, the first input impedance is the resistance of the high-impedance input amplifier U1, denoted as Rin1; the third input impedance is the resistance of the resistor R7, denoted as Rin3. One of the input impedance selection switches K1 is connected to the signal input terminal and the range selection circuit 120, and the other two input impedance selection switches K2 and K6 are respectively connected to the first input impedance (high-impedance input amplifier U1) and the third input impedance (resistor R7). When the input impedance selection switch K1 is closed, the resistance of the range circuit connected in the range selection circuit 120 is used as the second input impedance, denoted as Rin2. When the input impedance selection switch K2 is closed, the high-impedance input amplifier U1 is connected, that is, the first input impedance Rin1. When the input impedance selection switches K1 and K6 are closed, the resistor R7 is connected, that is, the third input impedance Rin3.

[0040] The input impedance selection switches K1, K2, and K6 receive a first control signal, and control the access of the corresponding input impedance individually or jointly according to the received first control signal. The first control signal comes from a processor or other processor in the back-end measurement circuit. The range selection circuit 120 includes three range circuits and three range selection switches (K3, K4, and K5), and the range selection switches are connected to the range circuits one by one, and are used to receive a second control signal and control the access of the corresponding range circuit according to the second control signal. The second control signal comes from a processor or other processor in the back-end measurement circuit.

[0041] The first range circuit includes resistors R1 and R6, wherein the resistor R1 is connected between the range selection switch and the signal conversion circuit 130, and the resistor R6 is connected between the signal conversion circuit 130 and the reference ground. The second range circuit includes resistors R2 and R5; and the third range circuit includes resistors R3 and R4. The structures of the second range circuit and the third range circuit are the same as those of the first range circuit, so they are not described in detail.

[0042] It should be noted that the sum of the resistances of the resistors R1 and R6 is equal to the sum of the resistances of the resistors R2 and R5 and the sum of the resistances of the resistors R3 and R4, and the sum of the resistances serves as the third input impedance.

[0043] The resistance ratio of the resistors R1 and R6 is different from the resistance ratio of the resistors R2 and R5 and the resistance ratio of the resistors R3 and R4, so different ranges can be selected.

[0044] It should also be noted that the resistors R1 and R6 can be equivalent resistors of multiple resistors. Similarly, the resistors R2, R5, R3, and R4 are also the same.

[0045] When the analog signal to be measured is input, the input impedance selection switches K1, K2, and K6 receive their respective first control signals to determine one of the three input impedances, so as to select the appropriate input impedance when the analog signal to be measured is a signal of a different type. When the input impedance selection switch K1 and the input impedance selection switch K6 are disconnected, and the input impedance selection switch K2 is closed, the input impedance is the input impedance Rin1 of the high-impedance input amplifier U1; when the input impedance selection switch K2 and the input impedance selection switch K6 are disconnected, and the input impedance selection switch K1 is closed, the input impedance is the resistance value of R1+R6 (or R2+R5, or R3+R4) and Rin2; when the input impedance selection switch K2 is disconnected, and the input impedance selection switch K1, the input impedance selection switch K5, and the input impedance selection switch K6 are closed, the input impedance is the resistance value Rin3 of the resistor R7. The resistance of resistor R7 is much smaller than the sum of the resistances of R3+R4; therefore, when the input impedance selection switch K2 is disconnected and the input impedance selection switch K1, the input impedance selection switch K5, and the input impedance selection switch K6 are closed, the resistance Rin3 is approximately equal to the resistance R7. The range selection switches K3, K4, and K5 are used to select the appropriate range gear according to the amplitude range of the analog signal to be measured. Different range gears are mainly realized by the resistance ratio of the resistors. When the range selection switch K3 is closed, the first range gear is selected, and the signal attenuation ratio is R6 / (R1+R6); when the range selection switch K4 is closed, the second range gear is selected, and the signal attenuation ratio is R5 / (R2+R5); when the range selection switch K5 is closed, the third range gear is selected, and the signal attenuation ratio is R4 / (R3+R4).

[0046] Since stray capacitance exists in all practical circuits, the analog signal to be measured will be affected by the stray capacitance, and analog signals to be measured with different frequencies will be affected differently.

[0047] In some embodiments, the first range circuit further includes capacitors C1 and C6, capacitor C1 is connected in parallel with resistor R1, and capacitor C6 is connected in parallel with resistor R6. Similarly, the second range circuit further includes capacitors C2 and C5, and the third range circuit further includes capacitors C3 and C4.

[0048] In this embodiment, each range circuit is designed with a two-stage RC network (such as R1 / / C1 for the first-stage RC compensation, and R4 / / C4 for the second-stage RC compensation) to compensate for stray capacitance to meet the requirements of high signal bandwidth, while making the amplitude-frequency curve of the circuit as flat as possible within the bandwidth to ensure that the signal is not distorted and improve the accuracy of time parameter measurement.

[0049] The resistors R1-R6 mentioned above can be equivalent resistors of multiple resistors respectively. In this case, each range circuit can also include multiple capacitors to form a multi-stage resistor-capacitor network with the multiple resistors.

[0050] The signal conversion circuit 130 includes: a buffer U2, connected to the range selection circuit 120, used to buffer the analog signal to be measured passing through the input impedance selection circuit 110 and the range selection circuit 120; a comparison unit, connected to the buffer U2, used to receive the analog signal to be measured passing through the input impedance selection circuit 110 and the range selection circuit 120, compare it with the high and low thresholds, and output the digital signal to be measured.

[0051] The analog signal to be measured is converted into a signal that meets the input amplitude range of the buffer U2 through the input impedance selection circuit 110 and the range selection circuit 120. The buffer U2 also plays an isolation role.

[0052] Among them, the comparison unit includes: a first comparator U3, used to receive the analog signal to be measured after passing through the input impedance selection circuit 110 and the range selection circuit 120, compare it with the high threshold VOH, and output the first digital signal to be measured; a second comparator U4, used to receive the analog signal to be measured after passing through the input impedance selection circuit 110 and the range selection circuit 120, compare it with the low threshold VOL, and output the second digital signal to be measured.

[0053] The first comparator U3 and the second comparator U4 are high-speed comparators, which invert the level signal by comparing with the threshold value and convert it into a digital signal.

[0054] The back-end measurement circuit 20 includes: a processor connected to the first comparator and the second comparator, and used to calculate the time parameter of the analog signal to be measured according to the first digital signal to be measured and the second digital signal to be measured.

[0055] The processor is, for example, a Field Programmable Gate Array (FPGA), which marks the transition edges of the first digital signal to be measured and the second digital signal to be measured, thereby achieving measurement of the time parameters of the analog signal to be measured.

[0056] In some embodiments, the processor may further output a first control signal and a second control signal.

[0057] An embodiment of the present application further provides a testing machine, comprising the time measuring device with multiple input impedances and multiple range selections in the above embodiment.

[0058] Since the test machine includes the time measurement device with multiple input impedances and multiple range selections in the above embodiments, it can solve the same technical problems and achieve the same technical effects, which will not be described in detail here.

[0059] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0060] The above 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 utility model 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 time measurement device with multiple input impedances and multiple range selections, characterized in that: The device comprises a front-end conditioning circuit and a back-end measurement circuit connected to the front-end conditioning circuit; wherein the front-end conditioning circuit comprises: An input impedance selection circuit, comprising a plurality of input impedances, for receiving an analog signal to be measured and a plurality of first control signals, and selecting access to any input impedance according to the plurality of first control signals; A range selection circuit, connected to the input impedance selection circuit, including a plurality of range circuits, for receiving a second control signal and selecting access to any range circuit according to the second control signal; The signal conversion circuit is connected to the range selection circuit and is used for receiving the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, and converting the analog signal to be measured into a digital signal to be measured.

2. The time measurement device with multiple input impedances and multiple range selections according to claim 1, characterized in that: The input impedance selection circuit also includes: A plurality of input impedance selection switches are connected to the plurality of input impedances in a one-to-one correspondence, and are used to receive the first control signal and control the access of corresponding input impedances according to the first control signal.

3. The time measurement device with multiple input impedances and multiple range selections according to claim 1, characterized in that: The range selection circuit also includes: A plurality of range selection switches are connected to the plurality of range circuits in a one-to-one correspondence, and are used to receive the second control signal and control access to the corresponding range circuits according to the second control signal.

4. The time measurement device with multiple input impedances and multiple range selections according to claim 3, characterized in that: The range circuit includes a first resistor and a second resistor; The first resistor is connected between the range selection switch and the signal conversion circuit; the second resistor is connected between the signal conversion circuit and a reference ground.

5. The time measurement device with multiple input impedances and multiple range selections according to claim 4, characterized in that: The sum of the resistance values ​​of the first resistor and the second resistor included in each of the range circuits is equal, but their ratios are not equal.

6. The time measurement device with multiple input impedances and multiple range selections according to claim 4, characterized in that: The range circuit also includes a first capacitor and a second capacitor; The first capacitor is connected in parallel with the first resistor, and the second capacitor is connected in parallel with the second resistor.

7. The time measurement device with multiple input impedances and multiple range selections according to claim 1, characterized in that: The signal conversion circuit comprises: A buffer, connected to the range selection circuit, for buffering the analog signal to be measured that passes through the input impedance selection circuit and the range selection circuit; The comparison unit is connected to the buffer and is used for receiving the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, comparing the analog signal with the high and low thresholds, and outputting the digital signal to be measured.

8. The time measurement device with multiple input impedances and multiple range selections according to claim 7, characterized in that: The comparison unit comprises: A first comparator, used for receiving the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, comparing the analog signal with a high threshold, and outputting a first digital signal to be measured; The second comparator is used to receive the analog signal to be measured after passing through the input impedance selection circuit and the range selection circuit, compare it with the low threshold value, and output a second digital signal to be measured.

9. The time measurement device with multiple input impedances and multiple range selections according to claim 8, characterized in that: The back-end measurement circuit comprises: A processor is connected to the first comparator and the second comparator, and is used to calculate the time parameter of the analog signal to be measured according to the first digital signal to be measured and the second digital signal to be measured.

10. A testing machine, characterized in that: A time measurement device comprising multiple input impedances and multiple range selections as claimed in any one of claims 1 to 9.

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