JP5025224B2 - Test device, driver comparator chip, response measuring device, and calibration method - Google Patents

Description

The present invention relates to a test apparatus, a driver comparator chip, a response measuring apparatus, and a calibration method . In particular, the present invention relates to a test apparatus for testing a device under test, a driver comparator chip provided in the test apparatus , a response measuring apparatus, and a calibration method .

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 comparator may have a different response time when a rising edge is input and a response time when a falling edge is input. If the response times of the rising edge and the falling edge are different, an error occurs in the measurement timing of the output signal from the device under test, so the test apparatus cannot test the device under test with high accuracy.
JP 2000-9801 A

  By the way, the test apparatus outputs the rising edge waveform and the falling edge waveform from an external reference driver, measures the response time of the comparator, and adjusts the response time of the comparator based on the measurement result. However, the test apparatus for making such adjustments has not been easy to measure because an external reference driver must be used to generate rising edge waveforms and falling edges with very small phase shifts.

Accordingly, an object of the present invention is to provide a test apparatus, a driver comparator chip, a response measuring apparatus, and a calibration method 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.

  In order to solve the above problems, according to a first aspect of the present invention, there is provided a test apparatus for testing a device under test, a signal generation unit for generating a test signal to be input to the device under test, A driver that outputs to the input / output pin of the test device, a comparator that is connected to the output terminal of the driver and the input / output pin of the device under test, detects the given signal, and the output signal of the device under test detected by the comparator Based on a determination unit for determining pass / fail of the device under test, and a response measurement device for detecting a difference between a response time for a rising edge of a signal and a response time for a falling edge in a comparator, The output terminal of the driver and the input terminal of the comparator are terminated to the ground potential via a transmission path having a predetermined propagation delay. In this state, the driver detects a first output waveform having a rising edge and a second output waveform having a falling edge, and a comparator detects the rising edge of the first output waveform. To a first measuring unit for measuring a first time until the comparator detects a falling edge of the first reflected waveform reflected by the end of the first output waveform, and a falling edge of the second output waveform A second measuring unit that measures a second time from when the comparator detects an edge until the comparator detects a rising edge of the second reflected waveform in which the second output waveform is reflected by the termination; A test apparatus is provided that includes a difference calculation unit that calculates a difference in response time based on the difference between the second time and the second time.

  In the second embodiment of the present invention, a driver for outputting a signal, a comparator for detecting a given signal, and a response for detecting a difference between a response time for the rising edge of the signal and a response time for the falling edge in the comparator. The response measuring device includes a rising edge in the driver in a state where the output end of the driver and the input end of the comparator are terminated to the ground potential through a transmission path having a predetermined propagation delay. A driver control unit that outputs an output waveform of 1 and a second output waveform having a falling edge, and the comparator detects the rising edge of the first output waveform, and then the first output waveform is reflected by the end. Measuring a first time until the comparator detects a falling edge of the first reflected waveform. The second unit from the time when the comparator detects the falling edge of the second output waveform to the time when the comparator detects the rising edge of the second reflected waveform reflected by the end of the second output waveform. Provided is a driver comparator chip having a second measuring unit for measuring time and a difference calculating unit for calculating a difference in response time based on a difference between the first time and the second time.

  In the third embodiment of the present invention, in a driver comparator having a driver that outputs a signal and a comparator that detects a given signal, the difference between the response time for the rising edge of the signal of the comparator and the response time for the falling edge The driver has a rising edge in a state where the output end of the driver and the input end of the comparator are terminated to the ground potential via a transmission path having a predetermined propagation delay. The driver control unit that outputs the output waveform and the second output waveform having the falling edge, and the comparator detects the rising edge of the first output waveform, and then the first output waveform is reflected by the termination. First time until the comparator detects the falling edge of the first reflected waveform After the comparator detects the falling edge of the first measurement unit to be measured and the second output waveform, until the comparator detects the rising edge of the second reflected waveform reflected by the end of the second output waveform There is provided a response measuring device comprising: a second measuring unit that measures the second time of the first time; and a difference calculating unit that calculates a difference in response time based on a difference between the first time and the second time.

  According to a fourth aspect of the present invention, there is provided 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, and the test signal to an input / output pin of the device under test. The output of the driver, the output terminal of the driver and the input / output pin of the device under test, and a comparator for detecting a given signal, and 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 measuring device that detects a difference between a response time with respect to a rising edge of a signal and a response time with respect to a falling edge in the comparator, and the response measuring device includes an output terminal of the driver and a comparator. In a state where the input terminal is terminated to the ground potential via a transmission path having a predetermined propagation delay, A driver control unit that outputs an output pulse waveform having a rising edge and a falling edge, a first measurement unit that measures the pulse width of the output pulse waveform detected by the comparator, and the output pulse waveform that is reflected at the end to the comparator A second measurement unit that measures the pulse width of the reflected pulse waveform that is input and detected by the comparator; and a difference calculation unit that calculates a difference in response time based on the difference between the pulse widths of the output pulse waveform and the reflected pulse waveform A test apparatus is provided.

  In the fifth embodiment of the present invention, a driver for outputting a signal, a comparator for detecting a given signal, and a response for detecting a difference between a response time for the rising edge of the signal and a response time for the falling edge in the comparator. The response measuring device includes a rising edge and a falling edge for the driver in a state where the output end of the driver and the input end of the comparator are terminated to the ground potential through a transmission path having a predetermined propagation delay. A driver control unit that outputs an output pulse waveform having an edge, a first measurement unit that measures the pulse width of the output pulse waveform detected by the comparator, and the output pulse waveform is reflected by the terminal and input to the comparator, and the comparator detects A second measurement unit for measuring the pulse width of the reflected pulse waveform Scan waveform and based on a difference between the pulse width of the reflected pulse waveform, to provide a driver comparator chip and a difference calculation unit for calculating a difference in response time.

  In the sixth embodiment of the present invention, in a driver comparator having a driver that outputs a signal and a comparator that detects a given signal, the difference between the response time for the rising edge of the signal of the comparator and the response time for the falling edge In which the driver output terminal and the comparator input terminal are terminated to the ground potential via a transmission path having a predetermined propagation delay, and the driver has a rising edge and a falling edge. A driver control unit for outputting an output pulse waveform having a first measurement unit for measuring a pulse width of the output pulse waveform detected by the comparator, and the output pulse waveform is reflected by the terminal and input to the comparator, which is detected by the comparator Second measurement to measure the pulse width of the reflected pulse waveform If, based on the difference between the pulse width of the output pulse waveform and the reflected pulse waveform, to provide a response measurement apparatus and a difference calculation unit for calculating a difference in response time.

  According to a seventh aspect of the present invention, there is provided a comparator calibration method for detecting an output signal from a device under test, provided in a test apparatus for testing the device under test, wherein the test signal is output to the device under test. A voltage that generates a signal potential that is output from the driver at the far end where the output end of the driver, the input end of the comparator, and the transmission path having a predetermined propagation delay are not connected to the output end of the driver. A first output waveform having a rising edge and a second output waveform having a falling edge are repeatedly output from the driver, and the comparator detects the rising edge of the first output waveform. , Until the comparator detects the falling edge of the first reflected waveform reflected by the far end of the first output waveform. From the time when the comparator detects the falling edge of the second output waveform to the time when the comparator detects the rising edge of the second reflected waveform reflected by the far end. Provided is a calibration method for measuring a second time and calculating a difference in response time based on a difference between the first time and the second time.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily 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. As an 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 a source of a test signal, a waveform mode signal that specifies a waveform mode, an expected value pattern that is used for pass / fail judgment, and other signals.

  The timing generator generates timing signals that define the timing of the leading and trailing edges of the waveform supplied to the device under test. As an example, the timing generator generates a timing signal that defines a rising edge or a falling edge of a test signal to be generated, and generates a strobe signal for timing determination by the comparator 16. The waveform 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. For example, the driver 14 receives the test signal generated by the signal generator 12 and supplies the 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 pin 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 an analog signal and converts it into two logic signals of a high level and a low level based on threshold values VOH and VOL of a predetermined level. The timing comparator receives two logic signals of a high level and a low level, individually determines the timing at the timing based on the strobe signal from the signal generation unit 12, and outputs it.

  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 has been determined by the comparator 16 and the expected value pattern from the signal generation unit 12.

The response measuring device 20 detects the difference between the response time for the rising edge of the signal and the response time for the falling edge in the comparator 16. Then, the response measuring 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 apparatus 20 has a period from the time when the falling edge is input to the input end of the comparator 16 to the time when the comparator 16 outputs a signal corresponding to the falling edge (falling response time T _F ) and a period (rising response time T _R ) from the time when the rising edge is input to the input terminal of the comparator 16 to the time when the comparator 16 outputs a signal corresponding to the rising edge (response time difference) Is detected. The response measuring device 20, based on the response time difference detected, so that the response time T _F rise response time T _R and the falling of the comparator 16 coincide, for example, to adjust the comparator 16.

  The response measurement apparatus 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 sends a rising edge to the driver 14 in a state where the output end of the driver 14 and the input end of the comparator 16 are terminated (short-circuited) to the ground potential via the transmission path 30 having a predetermined propagation delay. And a second output waveform having a falling edge are output. As an example, the driver control unit 32 causes the signal generation unit 12 to output a predetermined test pattern, thereby causing the driver 14 to output the first output waveform and the second output waveform.

  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 the transmission path 30, the far end where the output end of the driver 14 and the input end of the comparator 16 are not connected is short-connected to the ground potential via a short connection jig. The far end of the transmission path 30 is short-circuited via a short connection jig to a voltage source that generates substantially the same voltage as the signal potential (for example, high level potential or low level potential) output by the driver 14. Good.

  Here, the transmission path 30 may be a transmission path including, for example, a printed circuit board having a characteristic impedance of 50Ω, a coaxial cable, a coaxial connector, and the like that connects the device under test with the driver 14 and the comparator 16. 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. For example, the short connection jig may short-circuit the far end of the transmission path 30 and the ground potential in the performance board, or short-circuit the far end of the transmission path 30 and the ground potential in the socket board. 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, the test apparatus 10 includes, as an example, a voltage source that generates substantially the same voltage as a signal potential (for example, a high level potential or a low level potential) output from the driver 14, 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 and the voltage source that are not connected may be connected.

After the comparator 16 detects the rising edge of the first output waveform, the first measuring unit 34 detects the falling edge of the first reflected waveform that is reflected by the end of the transmission path 30. comparator 16 measures the first time T ₁ of the until it detects. The second measuring unit 36 compares the rising edge of the second reflected waveform in which the second output waveform is reflected by the end of the transmission path 30 after the comparator 16 detects the falling edge of the second output waveform. 16 measures a second time T ₂ of the until it detects.

Difference calculation unit 38, a first time T ₁ and based on a difference between T ₂ second time, calculates the difference between the response time of the comparator 16. Difference calculation unit 38, as an example, calculates the first time T ₁ and on the basis of the second measurement time with time T _2, the rise response time T _R of the comparator 16, the difference between the fall response time T _F To do.

The adjustment unit 40 adjusts at least one of the response time T _R for the rising edge in the comparator 16 or the response time T _F for the falling edge in the comparator 16 based on the difference in response time calculated by the difference calculation unit 38. For example, the adjustment unit 40 controls the measurement of the first time T1 or the second time T2. That is, for the purpose of detecting the rising edge or the falling edge, the adjustment unit 40 repeatedly generates the test signal for a long period that the reflected waveform disappears. And the adjustment part 40 detects an edge point, changing the timing of the strobe signal which generate | occur | produces from the signal generation part 12 in the state which generated the test signal in this way.

Thus, the adjustment unit 40, as an example, as the response time T _F rise and fall response times T _R are identical, it is possible to correct the timing of the strobe signal generated from the signal generator 12. 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. 3A shows an example of the input signal waveform and the output signal waveform of the comparator 16 when the driver 14 outputs a rising edge, and FIG. 3B shows the case where the driver 14 outputs a falling edge. An example of an input signal waveform and an output signal waveform of the comparator 16 is shown.

  The response measuring apparatus 20 executes the calibration process from step S210 to step S214 prior to the test of the device under test, for example. First, the response measuring apparatus 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 for connecting the far end of the transmission path 30 and the ground potential. 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.

Next, the response measuring device 20 measures a _first time T1 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 is input to the comparator 16. Note that, 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, from the time t311 to enter a rising edge of the first output waveform output from the driver 14, at time t312 which rise response time T _R delayed, searches the rising edge point of the first output waveform To detect. Here, the response measuring apparatus 20 repeatedly generates the waveform of FIG. 3A from the driver 14 for a period sufficient to search for an 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 propagates 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 to the VL voltage. The reflected waveform reflected at the terminal end is a waveform in which positive and negative are inverted from the output waveform output from the driver 14 because the terminal 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. After the reflected waveform disappears, the driver 14 has an internal resistance of 50Ω, for example. The far end of the transmission path 30 is short-connected 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.

Comparator 16, from the time t311 to the driver 14 has output a rising edge of the first output waveform, in twice the time _{T B} delayed by the time t313 the propagation delay time _{T A} in the transmission path 30, the first reflection waveform Input the falling edge of. Subsequently, the comparator 16 at time t314 which fall response time T _F delayed up from time t313 entered the fall of the first reflected waveform, detecting the falling edge of the first reflective wave. Here, the time from when the output waveform is output from the driver 14 to the input to the transmission path 30 and the time from when the reflected waveform is output from the transmission path 30 to the input to the comparator 16 are zero. Although the case is shown, it is the same even if there is a time difference. Then, the first measuring 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. The first time T ₁ until t314 is measured.

The response measuring device 20 measures the FIG 3 (B) a second time, as shown in _{T 2} for example (step S212). Here, the far end of the transmission path 30 reflects the reflected waveform by a terminal end grounded by a connection line of approximately 0Ω . In step S212, the driver control unit 32 first causes the driver 14 to output a second output waveform having a falling edge at a time t321 different from the time t311 at which 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, the two time t321 entered the falling edge of the output waveform, the fall response time T _F delayed time T322, the falling edge point of the second output waveform output from the driver 14 Search for and detect. Here, the response measuring apparatus 20 repeatedly generates the waveform of FIG. 3B from the driver 14 for a period sufficient to search for an edge point.

Further, the second output waveform having the falling edge output from the driver 14 is also input to the transmission path 30. When the second output waveform having the falling edge output from the driver 14 is input to the transmission path 30, the comparator 16 inputs the second reflected waveform having the rising edge from the transmission path 30. Comparator 16, from the time t321 to the driver 14 has output a falling edge of the second output waveform, in twice the time _{T B} delayed by the time t323 the propagation delay time _{T A} in the transmission path 30, the second reflection Enter the rising edge of the waveform .

Subsequently, the comparator 16 at time t324, which is delayed T _R min rise response time from the time t323 to enter a rising edge of a second reflected waveform, for detecting the rising edge of the second reflection waveform. 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. the second time until t324 to measure _{T 2.}

When the process of step S211 and step S212 is completed, then, the difference calculating section 38, the first time _{T 1} and based on a difference between _{T 2} second time, calculates the difference in response time in the comparator 16 (Step S213). Here, the first time T ₁ is a period from time t 311 when the comparator 16 inputs the rising edge of the first output waveform to time t 313 when the falling edge of the first reflected waveform is input by the comparator 16 ( That is, for twice the time T _B) of the propagation delay time in the transmission path 30, the rise response time T _R min short, the decay response time T _F min long time. That is, the first time _{T 1 is} expressed by _{T B} -T R + T _F.

On the other hand, the second time T ₂ are, fall period edges from time t321 the comparator 16 is input, to the time t323 to the rising edge of the second reflection waveform comparator 16 is input to the second output waveform (i.e. The time T _B ), which is twice the propagation delay time in the transmission path 30, is shorter by the fall response time T _F and longer by the rise response time T _R. That is, the second time _{T 2 are,} represented by _{T B} -T F + T _R.

Such represented by the following equation (1) when the first time T ₁ and the second time to calculate the difference between T _2.
(T ₁ −T ₂ ) = {(T _B −T _R + T _F ) − (T _B −T _F + T _R )} = 2 × (T _F −T _R ) (1)

Therefore, the difference calculation unit 38 sets the difference in response time (T _F −T _R ) to ½ of the difference between the first time T ₁ and the second time T ₂ as shown in the following equation (2). Can be calculated.
_{(T F -T R) = (} T 1 -T 2) / 2 ... (2)

  Next, the adjusting unit 40 adjusts the comparator 16 based on the response time difference calculated in step S213 so that the response time difference 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.

  According to the test apparatus 10 as described above, the response time of the comparator 16 can be set using the driver 14 already provided without supplying the comparator 16 with the rising edge and the falling edge from the external reference driver for testing. 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.

  FIG. 4 shows an example of the input signal waveform of the comparator 16 when the time interval from when the driver 14 outputs the rising edge to when it outputs the falling edge is larger than twice the propagation delay time in the transmission path 30. Show. FIG. 5 shows an example of the input signal waveform of the comparator 16 when the time interval from when the driver 14 outputs the rising edge to when it outputs the falling edge is smaller 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 predetermined time intervals. As an example, the driver controller 32, as shown in FIG. 4, the driver 14 is time interval T _X that outputs the rising edge and the second output waveform falling edge of the first output waveform, propagation in the transmission path 30 It controls the driver 14 to be greater than twice the time T _B of the delay time T _a.

In this case, the first measuring unit 34 measures the rising edge of the first output waveform, a pulse width of a pulse having a falling edge of the first reflected waveform, as T ₁ first time. That is, the first measuring unit 34 sets the time between the first edge detected first by the comparator 16 and the second edge detected second after the measurement is started as the first time T _1. taking measurement. The second measuring unit 36, and the trailing edge of the second output waveform, the pulse width of the pulse having a rising edge of a second reflected waveform is measured as T ₂ second time. That is, the second measuring unit 36 sets the time between the third edge detected by the comparator 16 third after the start of measurement and the fourth edge detected fourth as the second time T _2. taking measurement.

As an example, the driver controller 32, as shown in FIG. 5, the fall time interval T _X that outputs the edge of the first rising edge of the output waveform and a second output waveform, propagation in the transmission path 30 It controls the driver 14 to be less than twice the time T _B of the delay time T _a. In this case, the first measuring unit 34 measures the rising edge of the first output waveform, a pulse width of a pulse having a falling edge of the first reflected waveform, as T ₁ first time. That is, the first measuring unit 34 sets the time between the first edge detected first by the comparator 16 after the start of measurement and the third edge detected third as the first time T _1. taking measurement. The second measuring unit 36, and the trailing edge of the second output waveform, the pulse width of the pulse having a rising edge of a second reflected waveform is measured as T ₂ second time. That is, the second measuring unit 36 sets the time between the second edge detected by the comparator 16 second after the start of measurement and the fourth edge detected fourth as the second time T _2. taking measurement.

  FIG. 6 shows a configuration of a test apparatus 10 according to a first 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.

  The test apparatus 10 is a configuration example including a driver comparator chip 50 having 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 measuring 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 this modification, the set of the driver 14, the comparator 16, and the response measurement apparatus 20 can be easily mounted in the test apparatus 10.

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. Adjustment unit 40 refers to the value held in the difference storage unit 56, adjusts the rise response time T _R and the falling response time T _F of the comparator 16. Thereby, according to the test apparatus 10 according to the present modification, for example, the latest measurement result obtained by regular adjustment can be held, so that the response time of the comparator 16 changes with time. Also, the response time between the rising edge and the falling edge can be adjusted so that there is no deviation.

  FIG. 7 shows a configuration of a test apparatus 10 according to a second 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.

  In this modification, the response measurement 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, or connects the output end of the driver 14 and the input end of the comparator 16 via the transmission path 30. Switch between grounding. 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 includes a transmission line length that can measure the edge of the reflected waveform, 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 controls switching of the switch 62. The switch control unit 64 controls the transmission path 30 to be connected to an input / output pin of the device under test at the time of testing, and to connect the transmission path 30 to the ground potential at the time of 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. The path length calculation unit 66 calculates the propagation delay time T _A in the transmission path 30 based on the first time T ₁ and the second time T ₂ . Here, the sum of the first time T ₁ and the second time T ₂ are, is expressed by the following equation (3).
(T ₁ + T ₂ ) = {(T _B −T _R + T _F ) + (T _B −T _F + T _R )} = 2 × T _B (3)

Further, the propagation delay time T _A is T _B / 2. Therefore, the propagation delay time T _A is expressed by the following equation (4).
T _A = (T ₁ + T ₂ ) / 4 (4)

Therefore, the path length calculation unit 66 can calculate the propagation delay time T _A by a quarter of the sum of the first time T ₁ and the second time T ₂ . According to the test apparatus 10 in this manner according to this modification, it is possible to calculate the propagation delay time T _A of the transmission path 30 used in the test. Furthermore, the test apparatus 10, if provided with a response measurement device 20 for each pin resources, it is possible to calculate the propagation delay time T _A of the transmission path 30, for example, every pin.

  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.

  In the present modification, the test apparatus 10 includes a plurality of sets of drivers 14 and comparators 16 extending over several thousand channels, and a plurality of response measurement apparatuses 20 corresponding to the respective drivers 14 and comparators 16 on a one-to-one basis. 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. You may be prepared.

  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. Thereby, according to the test apparatus 10, the response time of the several comparator 16 can be adjusted in a short time.

  Further, as an example, the test apparatus 10 may further include an inter-pin timing control unit 70 that adjusts an inter-comparator skew between a plurality of sets of drivers 14 and comparators 16. 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 at a highly accurate 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.

In this modification, an output pulse is generated in which the time of the pulse width T ₃ of the output pulse waveform output from the driver 14 is shorter than the propagation delay time reflected and returned by the transmission path 30. In this modification, the driver control unit 32 rises to the driver 14 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. An output pulse waveform having an edge and a falling edge is output. When the output pulse waveform output from the driver 14 is input, the transmission path 30 outputs a reflected pulse waveform having a waveform inverted with respect to the output pulse waveform after a predetermined time.

The first measurement unit 34 measures the pulse width T ₃ of the output pulse waveform detected by the comparator 16. The second measuring unit 36 reflects the output pulse waveform at the end and inputs it to the comparator 16, and measures the pulse width T ₄ of the reflected pulse waveform detected by the comparator 16.

The difference calculating unit 38 calculates the difference in response time based on the difference between the pulse width T ₃ of the output pulse waveform and the pulse width T ₄ of the reflected pulse waveform. Difference calculation unit 38, as an example, the difference in response time may be calculated by half of the difference between the first time T ₁ and T ₂ a second time. According to such a test apparatus 10 according to the present modification, 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.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described 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.

1 shows a configuration of a test apparatus 10 according to an embodiment of the present invention. The measurement and adjustment processing flow of the response time of the comparator 16 by the response measuring device 20 is shown. (A) shows an example of an input signal waveform and an output signal waveform of the comparator 16 when the driver 14 outputs a rising edge, and (B) shows an example of the comparator 16 when the driver 14 outputs a falling edge. An example of an input signal waveform and an output signal waveform is shown. 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 greater than twice the propagation delay time in the transmission path 30 is shown. An example of the input signal waveform of the comparator 16 when the time interval from when the driver 14 outputs the rising edge to when it outputs the falling edge is smaller than twice the propagation delay time in the transmission path 30 is shown. The structure of the test apparatus 10 which concerns on the 1st modification of embodiment of this invention is shown. The structure of the test apparatus 10 which concerns on the 2nd modification of embodiment of this invention is shown. The structure of the test apparatus 10 which concerns on the 3rd modification of embodiment of this invention is shown. An example of the output waveform of the driver 14 and the reflected waveform by the transmission path 30 in the test apparatus 10 which concerns on the 4th modification of embodiment of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Test apparatus 12 Signal generation part 14 Driver 16 Comparator 18 Judgment part 20 Response measurement apparatus 22 Signal terminal 30 Transmission path 32 Driver control part 34 1st measurement part 36 2nd measurement part 38 Difference calculation part 40 Adjustment part 50 Driver comparator chip 56 Difference storage unit 62 Switch 64 Switch control unit 66 Path length calculation unit 70 Inter-pin timing control unit

Claims (12)

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;
A comparator connected to the output terminal of the driver and the input / output pin of the device under test to detect a given signal;
Based on the output signal of the device under test detected by the comparator, a determination unit for determining pass / fail of the device under test,
A response measuring device for detecting a difference between a response time for a rising edge of a signal and a response time for a falling edge in the comparator;
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 the ground potential via a transmission path having a predetermined propagation delay, the driver has a first output waveform having a rising edge and a falling edge. A driver control unit for outputting a second output waveform having an edge;
A first period from when the comparator detects the rising edge of the first output waveform to when the comparator detects a falling edge of the first reflected waveform reflected by the end of the first output waveform. A first measuring unit for measuring time;
A second period from when the comparator detects the falling edge of the second output waveform to 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 for measuring time;
A test apparatus comprising: a difference calculation unit that calculates a difference between the response times based on a difference between the first time and the second time.   The response measuring apparatus adjusts at least one of a response time for the rising edge in the comparator or a response time for the falling edge in the comparator based on the difference in response time calculated by the difference calculation unit. The test apparatus according to claim 1, further comprising a section. 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;
The first measurement unit measures, as the first time, a pulse width of a pulse having a rising edge of the first output waveform and a falling edge of the first reflected waveform;
The said 2nd measurement part measures the pulse width of the pulse which has the falling edge of the said 2nd output waveform, and the rising edge of the said 2nd reflected waveform as said 2nd time. Testing equipment. 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 1, wherein the driver control unit causes the plurality of drivers to output signals substantially simultaneously.   The response measurement apparatus further includes a switch for switching a connection path for connecting the driver, the comparator, and the device under test to either the device under test or the ground potential. Testing equipment.   The test apparatus according to claim 5, wherein the response measurement apparatus further includes a path length calculation unit that calculates a propagation delay time in the transmission path based on the first time and the second time. A driver that outputs a signal;
A comparator for detecting a given signal;
A response measuring device for detecting a difference between a response time for a rising edge of a signal and a response time for a falling edge in the comparator;
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 the ground potential via a transmission path having a predetermined propagation delay, the driver has a first output waveform having a rising edge and a falling edge. A driver control unit for outputting a second output waveform having an edge;
A first period from when the comparator detects the rising edge of the first output waveform to when the comparator detects a falling edge of the first reflected waveform reflected by the end of the first output waveform. A first measuring unit for measuring time;
A second period from when the comparator detects the falling edge of the second output waveform to 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 for measuring time;
A driver comparator chip having a difference calculation unit that calculates a difference between the response times based on a difference between the first time and the second time. A response measuring device for detecting a difference between a response time to a rising edge and a response time to a falling edge of a signal of the comparator in a driver comparator having a driver that outputs a signal and a comparator that detects a given signal. And
In a state where the output terminal of the driver and the input terminal of the comparator are terminated to the ground potential via a transmission path having a predetermined propagation delay, the driver has a first output waveform having a rising edge and a falling edge. A driver control unit for outputting a second output waveform having an edge;
A first period from when the comparator detects the rising edge of the first output waveform to when the comparator detects a falling edge of the first reflected waveform reflected by the end of the first output waveform. A first measuring unit for measuring time;
A second period from when the comparator detects the falling edge of the second output waveform to 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 for measuring time;
A response measurement apparatus comprising: a difference calculation unit that calculates a difference between the response times based on a difference between the first time and the second time. 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;
A comparator connected to the output terminal of the driver and the input / output pin of the device under test to detect a given signal;
Based on the output signal of the device under test detected by the comparator, a determination unit for determining pass / fail of the device under test,
A response measuring device for detecting a difference between a response time for a rising edge of a signal and a response time for a falling edge in the comparator;
The response measuring device includes:
In the state where the output terminal of the driver and the input terminal of the comparator are terminated to the ground potential through a transmission path having a predetermined propagation delay, an output pulse waveform having a rising edge and a falling edge is output to the driver. A driver control unit,
A first measuring unit for measuring a pulse width of the output pulse waveform detected by the comparator;
A second measuring unit that measures the pulse width of the reflected pulse waveform detected by the comparator, the output pulse waveform being reflected by the termination and input to the comparator;
A test apparatus comprising: a difference calculation unit that calculates a difference in response time based on a difference in pulse width between the output pulse waveform and the reflected pulse waveform. A driver that outputs a signal;
A comparator for detecting a given signal;
A response measuring device for detecting a difference between a response time for a rising edge of a signal and a response time for a falling edge in the comparator;
The response measuring device includes:
In the state where the output terminal of the driver and the input terminal of the comparator are terminated to the ground potential through a transmission path having a predetermined propagation delay, an output pulse waveform having a rising edge and a falling edge is output to the driver. A driver control unit,
A first measuring unit for measuring a pulse width of the output pulse waveform detected by the comparator;
A second measuring unit that measures the pulse width of the reflected pulse waveform detected by the comparator, the output pulse waveform being reflected by the termination and input to the comparator;
A driver comparator chip having a difference calculation unit that calculates a difference in response time based on a difference in pulse width between the output pulse waveform and the reflected pulse waveform. A response measuring device for detecting a difference between a response time to a rising edge and a response time to a falling edge of a signal of the comparator in a driver comparator having a driver that outputs a signal and a comparator that detects a given signal. And
In the state where the output terminal of the driver and the input terminal of the comparator are terminated to the ground potential through a transmission path having a predetermined propagation delay, an output pulse waveform having a rising edge and a falling edge is output to the driver. A driver control unit,
A first measuring unit for measuring a pulse width of the output pulse waveform detected by the comparator;
A second measuring unit that measures the pulse width of the reflected pulse waveform detected by the comparator, the output pulse waveform being reflected by the termination and input to the comparator;
A response measuring apparatus comprising: a difference calculating unit that calculates a difference in response time based on a difference in pulse width between the output pulse waveform and the reflected pulse waveform. 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,
An output terminal of a driver that outputs 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 not connected Connect the far end 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,
A first period from when the comparator detects the rising edge of the first output waveform to when the comparator detects the falling edge of the first reflected waveform reflected by the far end. Measure 1 time,
A first period from when the comparator detects a falling edge of the second output waveform to when the comparator detects a rising edge of the second reflected waveform reflected by the far end. Measure the time of 2,
A calibration method for calculating a difference in response time based on a difference between the first time and the second time.

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