WO2008050607A1

WO2008050607A1 - Tester, driver comparator chip, response measuring device, calibration method, and calibration device

Info

Publication number: WO2008050607A1
Application number: PCT/JP2007/069710
Authority: WO
Inventors: Yasuo Matsubara
Original assignee: Advantest Corporation
Priority date: 2006-10-25
Filing date: 2007-10-09
Publication date: 2008-05-02
Also published as: TWI352206B; TW200827746A; KR101138296B1; JP5025224B2; KR20090082434A; JP2008107188A

Abstract

A response measuring device (20) in which the output end of a driver (14) and the input end of a comparator (16) are terminated at the earth potential through a transmission path (30). The device (20) comprises a driver control section (32) for outputting a first output waveform having a rising edge and a second output waveform having a falling edge and a difference calculating section (38) for calculating the difference between the response times according to the difference between a first time from when a comparator (16) detects the rising edge of the first output waveform until when the comparator (16) detects the falling edge of a first reflection wave produced when the first output waveform is reflected by the termination and a second time from when the comparator (16) detects the falling edge of the second output waveform until when the comparator (16) detects the rising edge of a second reflection waveform produced when the second output waveform is reflected by the termination.

Description

Specification

Test device, driver comparator chip, response measuring device, calibration method, and calibration device

Technical field

[0001] The present invention relates to a test apparatus, a driver comparator chip, a response measuring apparatus, a calibration method, and a calibration apparatus. In particular, the present invention relates to a test apparatus for testing a device under test, a driver comparator chip and a response measuring apparatus provided in the test apparatus. This application is related to the following Japanese application. For designated countries where incorporation by reference of documents is allowed, the contents described in the following application are incorporated into this application by reference and made a part of this application.

1. Patent application 2006— 289780 Filing date October 25, 2006

Background art

[0002] A test apparatus for testing a semiconductor device or the like includes a comparator that takes an output signal output from a device under test into the test apparatus (see, for example, Patent Document 1). The response time when a rising edge is input may be different from the response time when a falling edge is input. If the response time of the rising edge and the falling edge is different, an error occurs in the measurement timing of the output signal from the device under test, so the test equipment cannot test the device under test with high accuracy. : JP 2000-9801 A

Disclosure of the invention

Problems to be solved by the invention

[0003] By the way, the test device outputs the rising force S edge waveform and the falling edge waveform from the external reference driver, measures the response time of the comparator, and adjusts the response time of the comparator based on the measurement result. Was. However, a test device that makes such adjustments must use an external reference driver to generate rising edge waveforms and falling edges with very little phase shift! /, So measurement is not easy. It was. Accordingly, an object of the present invention is to provide a test apparatus, a driver comparator chip, a response measuring apparatus, a calibration method, and a calibration apparatus that can solve the above-described problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous specific examples of the present invention.

Means for solving the problem

In order to solve the above problem, according to one example of the test apparatus according to the first aspect related to the innovation included in the present specification, a test apparatus for testing a device under test, the device under test being Connected to the signal generator that generates the test signal to be input to the driver, the driver that outputs the test signal to the input / output pin of the device under test, the output terminal of the driver and the input / output pin of the device under test A comparator that detects the signal, a determination unit that determines the pass / fail of the device under test based on the output signal of the device under test detected by the comparator, and a response time for the rising edge of the signal and a response for the falling edge in the comparator A response measuring device that detects a difference from time, and the response measuring device includes a driver output terminal and a comparator. Force end force A driver control unit that causes the driver to output an output waveform having a rising edge and a falling edge in a state where the driver is terminated at a predetermined potential via a transmission path having a predetermined propagation delay, and a rising edge of the output waveform When the comparator detects the edge, the falling edge of the reflected waveform whose output waveform is reflected by the termination, the falling edge of the output waveform, and the rising edge of the reflected waveform whose output waveform is reflected by the termination And a difference calculating unit for calculating a difference in response time based on

[0006] According to one example of a driver comparator chip according to the second aspect related to the innovation included in the present specification, a driver that outputs a signal, a comparator that detects a given signal, a signal in the comparator, A response measuring device that detects a difference between the response time for the rising edge and the response time for the falling edge, and the response measuring device is a transmission in which the output terminal of the driver and the input terminal of the comparator have a predetermined propagation delay. A driver control unit that causes the driver to output an output waveform having a rising edge and a falling edge in a state terminated at a predetermined potential via a path; The time at which the comparator detects the rising edge of the waveform, the falling edge of the reflected waveform reflected by the end of the output waveform, the falling edge of the output waveform, and the rising edge of the reflected waveform reflected by the end of the output waveform A driver comparator chip having a difference calculation unit for calculating a difference in response time based on

[0007] According to one example of a response measurement apparatus according to the third aspect related to the innovation included in the present specification, a comparator in a driver comparator having a driver that outputs a signal and a comparator that detects a given signal Is a response measuring device that detects the difference between the response time to the rising edge of the signal and the response time to the falling edge, and the output power of the driver and the input power of the comparator via a transmission path having a predetermined propagation delay In this state, the driver controller outputs an output waveform having a rising edge S and a falling edge, and the rising edge of the output waveform and the output waveform are reflected by the termination. Reflected waveform falling edge, output waveform falling edge, and output waveform There each rising edge of the reflection wave reflected by the end, based on the time the comparator detects, provide a response measuring device and a difference calculation unit for calculating a difference in response time.

[0008] According to one example of a calibration method according to the fourth aspect related to innovation included in the present specification, an output signal from a device under test included in a test apparatus for testing the device under test is detected. A method for calibrating a comparator, which connects an output terminal of a driver that outputs a test signal to a device under test, an input terminal of a comparator, and a transmission path having a predetermined propagation delay, and outputs an output terminal of the driver in the transmission path. The far end to which no signal is connected is connected to a voltage source that generates a signal potential output from the driver, and the driver outputs a first output waveform having a rising edge and a second output waveform having a falling edge. Output repeatedly, the comparator detects the rising edge of the first output waveform, and then the first output waveform is reflected by the far end. Measure the first time until the comparator detects the falling edge of the reflected waveform of S 1 and the comparator detects the falling edge of the second output waveform. Second time until the comparator detects the rising edge of the second reflected waveform reflected by the edge And a calibration method for calculating the difference in response time based on the difference between the first time and the second time.

[0009] According to one example of a calibration apparatus according to the fifth aspect related to innovation included in the present specification, the test for the purpose of calibrating the comparator provided in the test apparatus by the method related to the fourth aspect A calibration apparatus connected to the apparatus, a voltage source that is provided in the test apparatus and generates a voltage substantially the same as the signal potential output by the driver that outputs a test signal to the device under test, In the transmission path to which the output terminal and the input terminal of the comparator that detects the output signal from the device under test are connected, the far end where the driver output terminal is not connected and the short connection jig that connects the voltage source Provide a calibration device.

[0010] It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. A sub-combination of these feature groups can also be an invention.

Brief Description of Drawings

FIG. 1 shows a configuration of a test apparatus 10 according to an embodiment of the present invention.

FIG. 2 shows a flow of measurement and adjustment processing of the response time of the comparator 16 by the response measuring device 20.

[Figure 3] (A) shows an example of the input signal waveform and output signal waveform of comparator 16 when driver 14 outputs a rising edge, and (B) shows the edge of driver S falling edge S An example of the input signal waveform and output signal waveform of comparator 16 when output is shown.

[Figure 4] Comparator 16 input signal waveform when driver 14 outputs a rising edge and a falling edge is greater than twice the propagation delay time in transmission path 30! / An example is shown.

[Fig.5] Time interval force from driver 14 output of rising edge to output of falling edge Shows an example of input signal waveform of comparator 16 when the propagation delay time in transmission path 30 is less than twice .

FIG. 6 shows a configuration of a test apparatus 10 according to a first modification of the embodiment of the present invention.

FIG. 7 shows a configuration of a test apparatus 10 according to a second modification of the embodiment of the present invention. FIG. 8 shows a configuration of a test apparatus 10 according to a third modification of the embodiment of the present invention.

FIG. 9 shows an example of the output waveform of the driver 14 and the reflected waveform of the transmission path 30 in the test apparatus 10 according to the fourth modification of the embodiment of the present invention.

Explanation of symbols

[0012] 10 ··· Test equipment, 12 ··· Signal generator, 14 · "Driver, 16 · Comparator, 18 · Judger, 20 · · Response measuring device, 22 · · · Signal terminal, 30 ... Transmission path, 32 ... Driver control part, 34 ',' First measurement part, 36 ... Second measurement part, 38 ... Difference calculation part, 40 ... Adjustment part, 50 ... · 'Driver comparator chip, 56 · · · Difference memory, 62 · ·' Switch, 64 · 'Switch control, 66 · · Path length calculation, 70 · · Inter-pin timing control

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, (1) aspects of the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the invention according to the scope of the claims, and the features shown in the embodiments. Not all combinations are essential for the solution of the invention.

FIG. 1 shows a configuration of a test apparatus 10 according to the present embodiment. The test apparatus 10 is an apparatus for testing a device under test, and includes a signal generation unit 12, a driver 14, a comparator 16, a determination unit 18, and a response measurement device 20.

The signal generator 12 generates a test signal to be input to the device under test. For example, the signal generator 12 may include a pattern generator, a timing generator, and a waveform shaper. For example, the pattern generator generates a test pattern that is the source of the test signal, a waveform mode signal that specifies the waveform mode, an expected value pattern that is used for pass / fail judgment, and other signals.

[0016] The timing generator generates a timing signal that defines the timing of the leading and trailing edges of the waveform supplied to the device under test. For example, the timing generator generates a timing signal that defines the rising force or falling edge of the test signal to be generated, and also generates a strobe signal for timing determination by the comparator 16. The wave shaper receives the test pattern output from the pattern generator, and generates a test signal shaped into a predetermined waveform based on the waveform mode signal from the pattern generator.

The driver 14 outputs a test signal to the input / output pins of the device under test. dry For example, the node 14 receives the test signal generated by the signal generation unit 12 and supplies a driver signal converted into amplitudes of predetermined VH level and VL level to the device under test via the signal terminal 22.

The comparator 16 is connected to the output terminal of the driver 14 and the input / output pins of the device under test, and detects a given signal. As an example, the comparator 16 includes an analog comparator and a timing comparator. The analog comparator receives the analog signal and converts it into two logic signals of high level and low level based on the threshold values VOH and VOL of a predetermined level. The timing comparator receives two logic signals of high level and low level, individually determines the timing at the timing based on the strobe signal from the signal generator 12, and outputs the result.

The determination unit 18 determines pass / fail of the device under test based on the output signal of the device under test detected by the comparator 16. For example, the determination unit 18 determines pass / fail of the device under test based on the data whose timing is determined by the comparator 16 and the expected value pattern from the signal generation unit 12.

The response measuring device 20 detects a difference between the response time with respect to the rising edge of the signal and the response time with respect to the falling force S edge in the comparator 16. Then, the response measurement device 20 adjusts the response time of the comparator 16 based on the detected difference in response time of the comparator 16. More specifically, the response measuring device 20 has a period from the time when the falling edge is input to the input terminal of the comparator 16 to the time when the comparator 16 outputs a signal corresponding to the falling edge (falling force response). Time T) and comparator 1

F

The difference between the time when the rising edge is input to the input terminal of 6 and the time when the comparator 16 outputs a signal corresponding to the rising force S edge (rising force S response time)

R

Response time difference) is detected. Then, the response measuring device 20 matches the rising response time T and the falling response time T of the comparator 16 based on the detected response time difference.

R F

For example, the comparator 16 is adjusted.

The response measurement device 20 includes a driver control unit 32, a first measurement unit 34, a second measurement unit 36, a difference calculation unit 38, and an adjustment unit 40. The driver control unit 32 is configured such that the output terminal of the driver 14 and the input terminal of the comparator 16 are grounded via a transmission path 30 having a predetermined propagation delay. When the terminal is terminated (short-connected), the driver 14 is caused to output a first output waveform having a rising edge and a second output waveform having a falling force edge. For example, the driver control unit 32 outputs a first output waveform and a second output waveform from the driver 14 by causing the signal generation unit 12 to output a predetermined test pattern.

[0022] The output terminal of the driver 14 and the input terminal of the comparator 16 may be terminated (for example, short-circuited) to a predetermined potential other than the ground potential via the transmission path 30. In addition, the transmission path 30 is short-circuited to the ground potential via a far-end force short connection jig in which the output terminal of the driver 14 and the input terminal of the comparator 16 are not connected. In addition, the far end of the transmission path 30 is short-circuited to a voltage source that generates substantially the same voltage as the signal potential output from the driver 14 (for example, a no-level potential or a low-level potential) via a short connection jig. Good.

[0023] Here, the transmission path 30 is a transmission path that connects between the device under test and the driver 14 and the comparator 16 and includes, for example, a printed circuit board having a characteristic impedance of 50 Ω, a coaxial cable, a coaxial connector, and the like. It's okay. The transmission path 30 may be connected to the IC terminal of the device under test at the far end during a device test, and connected to a ground potential with a short connection jig at the far end instead of the device under test during measurement. In addition, for example, the short connection jig may be short-circuited between the far end of the transmission path 30 and the ground potential in the performance board! /, And grounded to the far end of the transmission path 30 in the socket board. The potential may be short-circuited, or the far end of the transmission path 30 and the ground potential may be short-circuited in a dummy device that contacts the IC socket. In addition, as an example, the test apparatus 10 includes a voltage source that generates substantially the same voltage as the signal potential output from the driver 14 (for example, a high level potential or a low level potential), and an output terminal of the driver 14 in the transmission path 30. A calibration device, such as a performance board, provided with a short connection jig for connecting the far end not connected to the voltage source may be connected.

[0024] After the comparator 16 detects the rising edge of the first output waveform, the first measurement unit 34 causes the first reflected waveform to be reflected by the end of the transmission path 30. Measure the first time T until comparator 16 detects the falling edge. No. 2 After the comparator 16 detects the falling edge of the second output waveform, the measuring unit 36 detects the rising edge of the second reflected waveform that is reflected by the end of the transmission path 30 by the comparator 16. Measure the second time T until detection.

2

[0025] The difference calculation unit 38 compares the difference between the first time T and the second time T with a comparator.

1 2

Calculate the difference in 16 response times. As an example, the difference calculation unit 38 determines the rise response time T of the comparator 16 and the rise time based on the measurement time of the first time T and the second time T.

2 R Calculates the difference in the falling response time T.

F

[0026] The adjustment unit 40 determines the response time T with respect to the rising edge in the comparator 16 or the rise time in the comparator 16 based on the difference in response time calculated by the difference calculation unit 38.

R

Adjust at least one of the response times T to the falling edge. The adjustment unit 40 is

F

As an example, the measurement of the first time T1 or the second time T2 is controlled. In other words, the adjustment unit 40 repeatedly generates a test signal for a long period that the reflected waveform disappears for the purpose of detecting a rising edge or a falling edge. Then, the adjustment unit 40 detects the edge point while sequentially changing the timing of the strobe signal generated from the signal generation unit 12 in the state where the test signal is generated in this way.

[0027] As a result, the adjustment unit 40, for example, uses the rise response time T and the fall response time.

R

The timing of the strobe signal generated from the signal generator 12 is adjusted so that

F

Correcting power S Therefore, the adjustment unit 40 can reduce the timing error between the rising edge and the falling edge of the comparator 16 during the device test.

FIG. 2 shows a measurement and calibration flow of the response time of the comparator 16 by the response measuring device 20. Fig. 3 (A) shows an example of the input signal waveform and output signal waveform of the comparator 16 when the driver 14 outputs a rising edge, and Fig. 3 (B) shows the output of the falling edge of the driver 14 An example of the input signal waveform and the output signal waveform of the comparator 16 is shown.

[0029] The response measuring apparatus 20 executes the calibration process from step S210 to step S214, for example, prior to the test of the device under test. First, the response measuring device 20 terminates the output end of the driver 14 and the input end of the comparator 16 to the ground potential by connecting, for example, a short connection jig to the far end of the transmission path 30 having a predetermined propagation delay. (Step S210). As an example, the response measuring apparatus 20 replaces the performance board on which the device under test is placed with a performance board provided with a short connection jig that connects the far end of the transmission path 30 to the ground potential. The output terminal of the driver 14 and the input terminal of the comparator 16 are terminated to the ground potential via the transmission path 30.

Next, the response measuring device 20 measures a first time T as shown in FIG. 3A, for example (step S211). In step S211, first, the driver control unit 32 causes the driver 14 to output a first output waveform having a rising edge at a designated time t311. That is, the output level of the driver 14 transitions from VL to VH. The first output waveform output from the driver 14 force is input to the comparator 16. Here, the time from when the output waveform is output from the driver 14 to when it is input to the comparator 16 is 0 for convenience of explanation, but there is no problem even if there is a time difference. Comparator 16 receives the first output waveform at time t312 delayed by rise response time T from time t311 when the rising edge of the first output waveform output from driver 14 is input.

R

Search for and detect rising edge points of shapes. Here, the response measuring apparatus 20 repeatedly generates the waveform of FIG. 3A from the driver 14 for a period sufficient to search for the edge point.

Further, the first output waveform having the rising edge output from the driver 14 is also input to the transmission path 30. Here, the transmission path 30 transmits the input output waveform to the termination side, and reflects the reflected waveform by the termination grounded by the connection line of approximately 0Ω.

Here, when the low-level potential VL is other than 0 volt (ground potential), the test apparatus 10 includes a voltage source that generates the VL voltage, and terminates the transmission path 30 by connecting it to the VL voltage. The reflected waveform reflected at the end is a waveform in which the polarity of the output waveform output from the driver 14 is inverted because the end of the transmission path 30 is connected to the ground potential! /. That is, the rising edge becomes a falling edge by being reflected at the grounded terminal, and the falling edge becomes a rising edge by being reflected at the grounded terminal. Therefore, the comparator 16 inputs the first reflected waveform having the falling edge from the transmission path 30 after the time for reciprocating the transmission path 30 has elapsed. Note that after the reflected waveform disappears, the driver 14 has an internal resistance of 50 Ω, for example. Also, the distance of transmission path 30 The end is short-circuited to the VL voltage. As a result, the output terminal of the driver 14 is forcibly set to a DC VL level although it outputs the VH level.

[0033] Comparator 16 compares the time t311 when driver 14 outputs the rising edge of the first output waveform with a time T that is twice the propagation delay time T in transmission path 30.

A B

At t313, the falling edge of the first reflected waveform is input. Subsequently, the comparator 16 detects the falling edge of the first reflected waveform at the time t314 delayed by the falling response time T from the time t313 when the falling edge of the first reflected waveform is input.

F

To do. Here, the time from when the output waveform is output from the driver 14 until the force is input to the transmission path 30 and the time from when the reflected waveform is output from the transmission path 30 to when it is input to the comparator 16 are 0. It is the same even if there is a force S and time difference indicating a certain case. The first measurement unit 34 detects the falling edge of the first reflected waveform reflected by the transmission path 30 from the time t312 when the rising edge of the first output waveform output from the driver 14 is detected. Measure the first time T until the detected time t314.

Next, the response measuring apparatus 20 measures a second time T as shown in FIG. 3B, for example (

2

Step S212). Here, the far end of the transmission path 30 reflects the reflected waveform by the end grounded by the connection line of approximately 0Ω. The test apparatus 10 includes a voltage source that generates a VH voltage, and terminates the transmission path 30 by connecting it to the VH voltage. In step S212, first, the driver control unit 32 causes the driver 14 to output the second output waveform having the falling edge at a time t321 different from the time t311 when the rising edge of the first output waveform is output. . That is, the output level of the driver 14 transitions from VH to VL. The second output waveform output from the driver 14 is input to the comparator 16. Comparator 16 outputs the second output waveform at time t322, which is delayed by the falling response time T from time t321, when the falling edge of the second output waveform output from driver 14 is input.

F

Search for and detect the falling edge point. Here, the response measuring apparatus 20 repeatedly generates the waveform of FIG. 3B from the driver 14 for a period sufficient to search for the edge point.

Further, the second output waveform having the falling edge output from the driver 14 is also input to the transmission path 30. Second with falling edge output from driver 14 When the output waveform is input to the transmission path 30, the comparator 16 inputs the second reflected waveform having a rising edge from the transmission path 30. Comparator 16 compares the second output waveform at time t323, which is delayed by time T that is twice the propagation delay time T in transmission path 30 from time t321 when driver 14 outputs the falling edge of the second output waveform. Reflected wave

A B

Enter the rising edge of the shape. Note that after the reflected waveform disappears, the driver 14 has an internal resistance of 50 Ω, for example. The far end of the transmission path 30 is short-circuited to the VH voltage. As a result, the output terminal of the driver 14 is forcibly set to the DC VH level even though the VL level is output.

[0036] Subsequently, at time t324, which is delayed by the rising response time T from time t3 23 when the rising edge of the second reflected waveform is input, the comparator 16 outputs the second reflected waveform.

R

Detect rising edge. Then, the second measurement unit 36 detects the rising edge of the second reflected waveform reflected by the transmission path 30 from the time t322 when the falling edge of the second output waveform output from the driver 14 is detected. Second time T up to t324

Measure 2.

[0037] After the processing of step S211 and step S212 is completed, the difference calculating unit 38 then determines the response time in the comparator 16 based on the difference between the first time T and the second time T.

1 2

Is calculated (step S213). Here, the first time T is from time t311 when the rising edge of the first output waveform is input by the comparator 16 to time t313 when the falling edge S of the first reflected waveform is input by the comparator 16 The rise response time T is shorter than the period (that is, the time T twice the propagation delay time in the transmission path 30).

B R

Fall response time T minutes longer. That is, the first time T is T T + T

F 1 B R F

[0038] On the other hand, during the second time T, the comparator 16 enters the falling edge of the second output waveform.

2

Ijt321 force, and the rising edge of the second reflected waveform rises for the period up to time t323 when the comparator 16 inputs (that is, the time T that is twice the propagation delay time in the transmission path 30). Fall response time T minutes shorter Rise response time T minutes longer

B F R

Between. That is, the second time T is represented by T T + T.

2 B F R

[0039] When the difference between the first time T and the second time T is calculated, the following equation (1) is obtained. expressed.

(T T) = {(T T + T) — (T T + T)} = 2 X (T — T)

1 2 Β R F Β F R F R

[0040] Therefore, the difference calculation unit 38 calculates the difference in response time (Τ-Τ) as the following equation (2).

F R

It can be calculated by 1/2 of the difference between the time Τ and the second time Τ.

1 2

(Τ -Τ) = (Τ Τ) / 2---(2)

F R 1 2

Next, the adjusting unit 40 adjusts the comparator 16 based on the difference in response time calculated in step S213 so that the difference in response time becomes substantially zero (step S214). For example, the adjustment unit 40 can correct the delay by adjusting the delay amount of the strobe signal supplied from the signal generation unit 12 to the comparator 16.

[0042] According to the test apparatus 10 as described above, the driver 14 already provided without using the external reference driver to supply the rising edge and falling force S to the comparator 16 for testing is used. The response time of the comparator 16 can be adjusted. Therefore, according to the test apparatus 10, the characteristics of the comparator 16 can be corrected at any time, and the device under test can be tested with high accuracy.

[0043] FIG. 4 shows that the time interval force S from when the driver 14 outputs the rising edge to the output of the falling edge S is greater than twice the propagation delay time in the transmission path 30. An example of an input signal waveform is shown. Figure 5 shows an example of the input signal waveform of the comparator 16 when the time interval from when the driver 14 outputs a rising edge to when it outputs a falling edge is less than twice the propagation delay time in the transmission path 30. Show.

The driver control unit 32 causes the driver 14 to continuously output the first output waveform and the second output waveform at a predetermined time interval. As an example, as shown in FIG. 4, the driver control unit 32 is a time interval at which the driver 14 outputs a rising edge and a second output waveform falling edge of the first output waveform.T force propagation delay time in the transmission path 30 Twice T

X A

The driver 14 is controlled so as to be larger than T.

B

[0045] In this case, the first measurement unit 34 measures the pulse width having the rising edge of the first output waveform and the falling edge of the first reflected waveform as the first time T. Determine. In other words, the first measurement unit 34 starts the measurement, and the comparator 16 The time between the first edge detected in step 2 and the second edge detected second is measured as the first time. Then, the second measuring unit 36 uses the width of the noise having the falling edge of the second output waveform and the rising edge of the second reflected waveform as the second time T.

2 Measure. That is, the second measuring unit 36 sets the time between the third edge detected by the comparator 16 after the start of measurement and the fourth edge detected fourth as the second time T. taking measurement.

2

Further, as an example, as shown in FIG. 5, the driver control unit 32 outputs a time interval T power transmission that outputs a rising edge of the first output waveform and a falling edge of the second output waveform.

X

Driver 14 is adjusted so that it is smaller than time T, which is twice the propagation delay time T in transmission path 30.

A B

Control. In this case, the first measuring unit 34 measures the pulse width having the rising edge of the first output waveform and the falling edge of the first reflected waveform as the first time T. That is, the first measurement unit 34 measures the time between the first edge detected by the comparator 16 first after the start of measurement and the third edge detected third as the first time T. To do. Then, the second measurement unit 36 measures the pulse width having the falling edge of the second output waveform and the rising edge of the second reflected waveform as the second time T. That is, the second measuring unit 36 starts the measurement and then compares the comparator 16

2

The time between the second edge detected for the third time and the fourth edge detected for the fourth time is measured as the second time T.

2

FIG. 6 shows a configuration of the test apparatus 10 according to the first modification example of the present embodiment. Since the test apparatus 10 according to this modification employs substantially the same configuration and function as the members having the same reference numerals shown in FIG. 1, the description thereof will be omitted except for the following differences.

[0048] The test apparatus 10 is a configuration example including a driver comparator chip 50 including a driver 14, a comparator 16, and a response measuring apparatus 20. As an example, the driver comparator chip 50 is obtained by integrating the driver 14, the comparator 16, and the response measuring device 20 on a semiconductor chip, a module, or a substrate. According to such a test apparatus 10 according to this modification, the response measurement apparatus 20 can be provided for each pin resource in which the driver 14 and the comparator 16 are provided. Furthermore, according to the test apparatus 10 according to the present modification, the set of the driver 14, the comparator 16, and the response measurement apparatus 20 is simplified in the test apparatus 10. Can be implemented.

In addition, the response measurement device 20 further includes a difference storage unit 56. The difference storage unit 56 holds a value corresponding to the difference in response time calculated at the time of adjustment. The adjustment unit 40 refers to the value held in the difference storage unit 56, and the rising response time T and the comparator 16

R

Adjust fall response time T. As a result, the test apparatus 10 according to this variation

F

For example, the latest measurement results obtained by regular adjustment can be held, so even if the response time of the comparator 16 changes with time, the response time between the rising edge and falling edge It can be adjusted so that there is no deviation.

FIG. 7 shows a configuration of the test apparatus 10 according to the second modification example of the present embodiment. Since the test apparatus 10 according to this modification employs substantially the same configuration and function as the members having the same reference numerals shown in FIG. 1, the description thereof will be omitted except for the following differences.

[0051] In this modification, the response measuring device 20 further includes a switch 62 and a switch control unit 64. The switch 62 switches whether the transmission path 30 connecting the driver 14 and the comparator 16 and the device under test is connected to the device under test or the ground potential! That is, the switch 62 connects the output end of the driver 14 and the input end of the comparator 16 to the device under test via the transmission path 30, and the transmission path 30 connects the output end of the driver 14 and the input end of the comparator 16. Switch between grounding through. The switch 62 may be mounted on a HiFix or performance board. Further, when the board (pin electronics board) on which the driver 14 is mounted and the transmission line length that can measure the edge of the reflected waveform are included, the switch 62 may be mounted on the pin electronics board. Further, the switch 62 may be a semiconductor switch when a semiconductor switch is applicable.

The switch control unit 64 switches and controls the switch 62. The switch control unit 64 controls the transmission path 30 to be connected to the input / output pin of the device under test during the test, and to connect the transmission path 30 to the ground potential during the adjustment. According to the test apparatus 10 according to such a modification, the response time of the comparator 16 can be adjusted using the transmission path 30 used in the test.

In addition, the response measurement device 20 may further include a path length calculation unit 66. Path length calculator 66 Is the propagation delay in transmission path 30 based on the first time T and the second time Τ

1 2

Calculate time Τ. Here, the sum of the first time Τ and the second time Τ is given by the following equation (3).

A 1 2

It is expressed as follows.

(T + T) = {(Τ -Τ + Τ) + (Τ -Τ + Τ)} = 2 ΧΤ '' (3)

1 2 B R F B F R B

Further, the propagation delay time T is T / 2. From this, the propagation delay time Τ is

A B A

It is expressed as equation (4).

T = (T + Τ) / 4/4 '' (4)

A 1 2

Accordingly, the path length calculation unit 66 determines the propagation delay time T as the first time T and the second time T.

It can be calculated by a quarter of the sum of A 1 2. As described above, according to the test apparatus 10 according to this modification, the propagation delay time T of the transmission path 30 used in the test can be calculated.

A

it can. Furthermore, if the test apparatus 10 includes the response measurement apparatus 20 for each pin resource, the propagation delay time T of the transmission path 30 can be calculated for each pin, for example.

A

FIG. 8 shows a configuration of a test apparatus 10 according to a third modification of the present embodiment. Since the test apparatus 10 according to this modification employs substantially the same configuration and function as the members having the same reference numerals shown in FIG. 1, the description thereof will be omitted except for the following differences.

[0057] In this modification, the test apparatus 10 includes a plurality of sets of dryers 14 and comparators 16 extending to several thousand channels, and a plurality of response measuring apparatuses 20 corresponding one-to-one to the respective drivers 14 and comparators 16. With. In this case, the plurality of response measuring apparatuses 20 may include a common driver control unit 32. That is, the test apparatus 10 includes a plurality of first measurement units 34, a plurality of second measurement units 36, a plurality of second measurement units 36, and an adjustment unit 40 that correspond one-to-one to a plurality of sets of drivers 14 and comparators 16. May be provided.

The driver control unit 32 causes the plurality of drivers 14 to output signals substantially simultaneously. Then, the plurality of response measuring devices 20 calculate the difference between the response times of the plurality of comparators 16 in parallel, and adjust the response times of the plurality of comparators 16 in parallel. Thus, according to the test apparatus 10, the force S can be adjusted to adjust the response times of the plurality of comparators 16 in a short time.

[0059] In addition, the test apparatus 10 further includes, as an example, an inter-pin timing control unit 70 that adjusts an inter-comparator skew between a plurality of sets of drivers 14 and comparators 16. Good. The inter-pin timing control unit 70 may adjust the inter-comparator skew after each of the plurality of response measuring devices 20 individually adjusts the response time of the comparator 16. According to this, as a result of adjusting the inter-comparator skew with respect to both the rising edge and the falling edge between the plurality of comparators 16, it is possible to realize a device test with high accuracy timing.

FIG. 9 shows an example of the output waveform of the driver 14 and the reflected waveform of the transmission path 30 in the test apparatus 10 according to the fourth modification of the present embodiment. Since the test apparatus 10 according to this modification employs substantially the same configuration and function as those in FIG. 1, the description thereof will be omitted except for the following differences.

[0061] In this modification, the time of the pulse width T of the output waveform output from the driver 14 is transmitted.

Three

An output can be generated that is shorter than the propagation delay time reflected by path 30 and returning. In this modification, the driver control unit 32 is in a state where the output end of the driver 14 and the input end of the comparator 16 are terminated to the ground potential via the transmission path 30 having a predetermined propagation delay! /, Thus, the driver 14 outputs an output waveform having a rising edge and a falling edge. When an output waveform output from the driver 14 is input, the transmission path 30 outputs a reflected pulse waveform that is an inverted waveform of the output pulse waveform after a predetermined time.

[0062] The first measurement unit 34 measures the pulse width T of the output waveform detected by the comparator 16.

3 to do. The second measuring unit 36 reflects the output waveform at the end and is input to the comparator 16 and measures the pulse width T of the reflected waveform detected by the comparator 16.

Four

[0063] The difference calculating unit 38 calculates the pulse width T of the output pulse waveform and the pulse width of the reflected pulse waveform.

Three

Based on the difference in T, the difference in response time is calculated. As an example, the difference calculation unit 38 responds.

Four

The difference in answer time may be calculated as 1/2 of the difference between the first time T and the second time T. this

1 2

According to the test apparatus 10 according to this modified example, the response time of the comparator 16 can be adjusted using the driver 14 already provided, similarly to the test apparatus 10 shown in FIG.

[0064] As described above, the aspect (1) of the present invention has been described using the embodiment, but the technical scope of the present invention. Is not limited to the range described in the above embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

Claims

The scope of the claims

[1] A test apparatus for testing a device under test,

A signal generator for generating a test signal to be input to the device under test, a driver for outputting the test signal to an input / output pin of the device under test, an output terminal of the driver and a front of the device under test A comparator connected to the write output pin and detecting a given signal;

A determination unit for determining pass / fail of the device under test based on an output signal of the device under test detected by the comparator;

A response measuring device for detecting a difference between a response time to the rising edge of the signal and a response time to the falling edge of the signal in the comparator;

With

The response measuring device includes:

In a state where the output terminal of the driver and the input terminal of the comparator are terminated to a predetermined potential via a transmission path having a predetermined propagation delay, the rising edge S and the falling edge are supplied to the driver. A driver control unit that outputs an output waveform including: a rising edge of the output waveform; a falling edge of a reflected waveform reflected by a termination of the output waveform; a falling edge of the output waveform; and the output waveform A test apparatus comprising: a difference calculating unit that calculates a difference in response time based on a time at which the comparator detects each rising edge of the reflected waveform reflected by the terminal end.

2. The test apparatus according to claim 1, wherein the predetermined potential is a ground potential.

[3] The driver control unit causes the driver to output a first output waveform having a rising edge and a second output waveform having a falling edge,

The comparator detects the rising edge of the first output waveform after the comparator detects the falling edge of the first output waveform, and then the falling edge of the first reflected waveform reflected by the termination of the first output waveform. A first measuring unit for measuring a first time until,

After the comparator detects the falling force S edge of the second output waveform, the rising edge of the second reflected waveform reflected by the end of the second output waveform is And a second measuring unit that measures a second time until the comparator detects it, and the difference calculating unit is configured to determine the response time based on a difference between the first time and the second time. Calculate the difference between

The test apparatus according to claim 1.

[4] The response measuring device may be configured based on the response time difference calculated by the difference calculation unit.

4. The test apparatus according to claim 3, further comprising an adjustment unit that adjusts at least one of a response time to the rising edge in the comparator or a response time to the falling edge in the comparator.

[5] The driver control unit controls the driver so that a time interval at which the driver outputs the first output waveform and the second output waveform is greater than twice the propagation delay time of the transmission path. And

The first measurement unit measures a pulse width of a pulse having a rising edge of the first output waveform and a falling edge of the first reflected waveform as the first time, and (2) The measurement unit measures the pulse width of the pulse having the falling edge of the second output waveform and the rising edge of the second reflected waveform as the second time.

The test apparatus according to claim 3.

[6] The test apparatus includes a plurality of sets of the driver and the comparator,

The response measuring device includes:

A plurality of the first measurement units, a plurality of the second measurement units, and a plurality of the difference calculation units, which correspond one-to-one to the plurality of sets of the drivers and the comparators,

The test apparatus according to claim 3, wherein the driver control unit causes the plurality of drivers to output signals substantially simultaneously.

[7] The response measuring apparatus further includes a switch that switches whether a transmission path connecting the driver and the comparator and the device under test is connected to the device under test or the ground potential. The test apparatus according to claim 3.

[8] The response measurement apparatus may further include a path length calculation unit that calculates a propagation delay time in the transmission path based on the first time and the second time. Testing equipment.

[9] A driver that outputs a signal;

A comparator for detecting a given signal;

With

The response measuring device includes:

In a state where the output terminal of the driver and the input terminal of the comparator are terminated to a predetermined potential via a transmission path having a predetermined propagation delay, the rising edge S and the falling edge are supplied to the driver. A driver control unit that outputs an output waveform including: a rising edge of the output waveform; a falling edge of a reflected waveform reflected by a termination of the output waveform; a falling edge of the output waveform; and the output waveform A driver comparator chip comprising: a difference calculation unit that calculates a difference in the response time based on a time at which the comparator detects each rising edge of the reflected waveform reflected by the terminal end.

10. The driver comparator chip according to claim 9, wherein the predetermined potential is a ground potential.

[11] The driver control unit causes the driver to output a first output waveform having a rising edge and a second output waveform having a falling edge,

From the time when the comparator detects the falling edge S of the second output waveform until the time when the comparator detects the rising edge of the second reflected waveform reflected by the end of the second output waveform A second measuring unit that measures the second time of the second time, and the difference calculating unit calculates the difference in the response time based on a difference between the first time and the second time

The driver comparator chip according to claim 9.

[12] A driver having a driver for outputting a signal and a comparator for detecting a given signal. A response measuring device for detecting the difference between the response time of the comparator signal to the rising edge and the response time to the falling force edge of the comparator,

In a state where the output terminal of the driver and the input terminal of the comparator are terminated to a predetermined potential via a transmission path having a predetermined propagation delay, the rising edge S and the falling edge are supplied to the driver. A driver control unit that outputs an output waveform including: a rising edge of the output waveform; a falling edge of a reflected waveform reflected by a termination of the output waveform; a falling edge of the output waveform; and the output waveform A response measuring device comprising: a difference calculating unit that calculates a difference in the response time based on a time at which the comparator detects each rising edge of the reflected waveform reflected by the terminal end.

13. The response measuring apparatus according to claim 12, wherein the predetermined potential is a ground potential.

[14] The driver control unit causes the driver to output a first output waveform having a rising edge and a second output waveform having a falling edge,

The response measurement device according to claim 12.

[15] The driver control unit causes the driver to output an output pulse waveform having a rising edge and a falling edge,

A first measurement unit for measuring a pulse width of the output waveform detected by the comparator;

The output waveform is reflected by the terminal and input to the comparator, and the waveform is reflected. And a second measuring unit for measuring the width of the reflected noise waveform detected by the comparator.

The difference calculating unit calculates the difference in response time based on a difference in pulse width between the output pulse waveform and the reflected pulse waveform.

The test apparatus according to claim 1.

[16] The driver control unit causes the driver to output an output pulse waveform having a rising edge and a falling edge,

A second measuring section that reflects the output waveform at the end and is input to the comparator, and measures the width of the reflected noise waveform detected by the comparator;

The driver comparator chip according to claim 9.

[17] a driver control unit that outputs an output waveform having a rising edge and a falling edge to the driver, and an output terminal force S of the driver and an input terminal force S of the comparator;

The response measuring device according to claim 12.

[18] A comparator calibration method for detecting an output signal from the device under test, provided in a test apparatus for testing the device under test, A driver output terminal for outputting a test signal to the device under test, an input terminal of the comparator, and a transmission path having a predetermined propagation delay are connected, and an output terminal of the driver in the transmission path is connected. The far end not connected to a voltage source that generates a signal potential output from the driver,

The driver repeatedly outputs a first output waveform having a rising edge and a second output waveform having a falling edge,

The comparator detects the falling edge of the first reflected waveform in which the first output waveform is reflected by the far end after the comparator detects the rising edge S of the first output waveform. Measure the first time until

The comparator detects the rising edge of the second reflected waveform in which the second output waveform is reflected by the far end after the comparator detects the falling edge S edge of the second output waveform. Measure the second time until

A calibration method for calculating a difference in response time based on a difference between the first time and the second time.

A calibration device connected to the test device for the purpose of calibrating a comparator provided in the test device by the method of claim 18, comprising:

A voltage source that is provided in the test apparatus and generates a voltage substantially the same as a signal potential output by a driver that outputs a test signal to a device under test;

In the transmission path to which the output end of the driver and the input end of the comparator for detecting the output signal from the device under test are connected, the output end of the driver is touched! /, NA! /, The far end, A short connection jig for connecting the voltage source;

A calibration device comprising: