JP5235128B2 - Test system - Google Patents

Description

  The present invention relates to a test system and a power supply device.

In general, a test system for testing a device under test such as a semiconductor circuit is provided with a power supply apparatus that supplies power to the device under test. The power supply device applies various power supply voltages and power supply currents determined by the test contents and the specifications of the device under test to the device under test. For this reason, the test apparatus is provided with a high-performance programmable power supply device (see, for example, Patent Document 1). In the programmable power supply device, for example, each of voltage and current can be controlled by a program.
JP-A-8-29495

  However, since the conventional programmable power supply has a complicated configuration and is expensive, it is not preferable to use the conventional programmable power supply for the test system when the power supply performance up to that point is not necessary. For this reason, there has been a demand for a power supply apparatus that can output various power supply voltages with a simple configuration and at a low cost.

In order to solve the above-described problem, in a first aspect of the present invention, a test system for testing a device under test, which is a performance board on which the device under test is placed, and supplies power to the device under test A power supply apparatus and a test unit that measures predetermined characteristics of the device under test and determines whether the device under test is good or bad. The power supply apparatus is provided on the test board and corresponds to the input voltage applied to the input terminal A power supply unit that generates a power supply voltage and adjusts and outputs the power supply voltage according to a control signal supplied to the control terminal, and a transmission board that transmits the power supply voltage to the test board provided with the power supply unit and transmits the power supply voltage. a power supply voltage in the road, and generates a control signal according to a difference between a predetermined reference voltage, and a feedback unit for inputting to the control terminal of the power supply unit, response to the supply voltage to be supplied to the device under test Te, a voltage control unit for controlling the reference voltage, the supply voltage applied to the device under test, a voltage detecting section for detecting the transmission path on the performance board, the power supply voltage to which the voltage detecting unit detects a predetermined threshold value Provided is a test system including an abnormality detection unit that stops output of power from a power supply unit when the voltage is higher than a voltage .

  In a second aspect, the power supply device supplies power to a load, generates a power supply voltage according to an input voltage applied to an input terminal, and supplies the power supply voltage according to a control signal applied to a control terminal. A control signal is generated in accordance with the difference between the power supply unit that is adjusted and output, the power supply voltage output from the power supply unit, and a predetermined reference voltage, and the feedback signal is input to the control terminal of the power supply unit, and is supplied to the load. A power supply device including a voltage control unit that controls a reference voltage according to a power supply voltage to be provided is provided.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a diagram showing a test system 10 according to one embodiment together with a device under test 200. The device under test 200 may be a semiconductor chip, for example. The test system 10 tests the device under test 200. The test system 10 of this example includes a test unit 12, a test control unit 14, and a power supply device 100. Note that the test system 10 may include a plurality of test units 12 and a power supply device 100, and may test a plurality of devices under test 200 in parallel.

  The power supply apparatus 100 supplies power to the device under test 200. The power supply apparatus 100 may output a voltage corresponding to information set by a user or the like. The test unit 12 measures predetermined characteristics of the device under test 200 to determine whether the device under test 200 is good or bad. For example, the test unit 12 may measure whether or not the device under test 200 outputs the same pattern as the expected value pattern when a predetermined pattern is input to the device under test 200. Further, the test unit 12 may measure whether or not the power supply current or the power supply voltage when the device under test 200 is in operation or at rest is within a predetermined range.

  The test control unit 14 controls the test unit 12 and the power supply device 100. For example, the test control unit 14 may supply the test unit 12 with a trigger signal for starting a test of the device under test 200, a test pattern indicating a pattern to be applied to the device under test 200, and the like. Further, the test control unit 14 may set a voltage value to be output by the power supply device 100 in the power supply device 100.

  FIG. 2 is a diagram illustrating a configuration example of the power supply device 100. The power supply apparatus 100 includes a power supply unit 110, a transmission path 120, a feedback unit 130, and a voltage control unit 160. The power supply unit 110 generates a power supply voltage Vo corresponding to the input voltage Vi applied to the input terminal In and outputs it from the output terminal Out. The input voltage Vi may be a constant DC voltage. The power supply unit 110 may generate the power supply voltage using a power amplifier that drives the input voltage Vi as the power supply voltage.

  Further, the power supply unit 110 adjusts and outputs the voltage value of the power supply voltage Vo according to a control signal given to the control terminal Adj. For example, the power supply unit 110 may adjust the voltage value of the power supply voltage Vo according to the difference between the voltage level of the control signal and a predetermined voltage level. The power supply unit 110 may be an LDO (Low Drop Out) power supply or a DC-DC power supply. The LDO power supply is provided with a power amplifier between the input terminal In and the output terminal Out, compares the output voltage Vo with the voltage of the control signal, controls the on-resistance of the power transistor based on the comparison result, and sets the output voltage to a constant voltage. It may be a power source to do. The on-resistance of the power transistor can be adjusted by controlling the gate current of the power transistor.

  The transmission path 120 transmits the power supply power output from the power supply unit 110 to the device under test 200. For example, the transmission path 120 may include a cable that connects a test board on which the power supply unit 110 is provided and a performance board on which the device under test 200 is placed.

  The feedback unit 130 generates a control signal according to the difference between the power supply voltage Vo output from the power supply unit 110 and a predetermined reference voltage. Further, the feedback unit 130 inputs the generated control signal to the control terminal Adj of the power supply unit 110. The feedback unit 130 may detect the power supply voltage Vo transmitted through the transmission line 120. The feedback unit 130 may be provided on the same test board as the power supply unit 110.

  In addition, the voltage control unit 160 controls the reference voltage in the feedback unit 130 according to the power supply voltage Vo to be supplied to the device under test 200. For example, the test control unit 14 may function as the voltage control unit 160. The test control unit 14 may control the reference voltage in accordance with a test program given from a user or the like.

  Since the power supply unit 110 adjusts the voltage level of the power supply voltage Vo according to the voltage level of the control signal, the voltage level of the power supply voltage Vo output from the power supply unit 110 is set by controlling the reference voltage in the feedback unit 130. can do. As described above, according to the power supply device 100 of this example, the power supply unit 110 having a simple configuration such as an LDO power supply is used, and the control signal to the power supply unit 110 is controlled, thereby realizing a variable voltage power supply at low cost. can do.

  The feedback unit 130 of this example includes a voltage follower circuit 132, a differential circuit 134, a variable voltage source 136, a resistor 138, a resistor 140, a resistor 142, and a resistor 144. Note that the configuration of the feedback unit 130 is not limited to the configuration of this example. The feedback unit 130 may have a configuration capable of generating a control signal in which the voltage level of the detected power supply voltage Vo is adjusted according to the control from the voltage control unit 160.

  The voltage follower circuit 132 receives the power supply voltage Vo output from the power supply unit 110, and outputs substantially the same voltage as the power supply voltage Vo. The voltage follower circuit 132 may be electrically connected to the transmission line 120 in the vicinity of the power supply unit 110. For example, the voltage follower circuit 132 may be electrically connected to the transmission line 120 in a test board provided with the power supply unit 110.

  The variable voltage source 136 generates a reference voltage according to the control from the voltage control unit 160. For example, the variable voltage source 136 may include a DA converter that outputs a voltage corresponding to a digital value given from the voltage control unit 160. The voltage control unit 160 may generate the digital value using software such as a test program given by the user.

  The differential circuit 134 inputs a voltage corresponding to the difference between the voltage output from the voltage follower circuit 132 and the reference voltage output from the variable voltage source 136 to the control terminal Adj of the power supply unit 110. In the differential circuit 134 of this example, a voltage obtained by dividing the voltage output from the voltage follower circuit 132 by the resistor 140 and the resistor 142 is applied to the positive input terminal. The variable voltage source 136 is connected to the negative input terminal of the differential circuit 134 via a resistor 138. Further, the output terminal and the negative input terminal of the differential circuit 134 are connected via a resistor 144. Resistors 138 to 144 may have the same resistance value.

  With such a configuration, the differential circuit 134 adjusts the voltage level of the power supply voltage Vo detected by the voltage follower circuit 132 according to the reference voltage generated by the variable voltage source 136, and controls the control terminal Adj of the power supply unit 110. Can be entered. Therefore, the power supply voltage Vo output from the power supply unit 110 can be controlled by controlling the reference voltage.

  Note that the feedback unit 130 does not have to include the voltage follower circuit 132. In this case, each resistance value of the resistors 138 to 144 is preferably sufficiently larger than the impedance of the transmission line 120. The feedback unit 130 may use a comparison circuit that outputs a voltage corresponding to the comparison result between the power supply voltage Vo and the reference voltage, instead of the differential circuit 134 and the resistor 138 to the resistor 144.

  FIG. 3 is a diagram illustrating another configuration example of the power supply device 100. The power supply device 100 of this example further includes a current detection unit 121 and an abnormality detection unit 126 in addition to the configuration of the power supply device 100 described with reference to FIG. Other configurations may be the same as those of the power supply apparatus 100 described in relation to FIG. However, the power supply unit 110 of this example stops the output of the power supply in response to a stop signal given to the stop terminal En.

  The current detection unit 121 detects a power supply current output from the power supply unit 110. The current detection unit 121 may detect a current flowing through the transmission line 120 near the power supply unit 110. The current detection unit 121 of this example may be provided on the same test board as the power supply unit 110.

  The current detection unit 121 includes a detection resistor 122 and a detector 124. The detection resistor 122 is provided in the transmission line 120 on the power supply unit 110 side of the detection point where the feedback unit 130 detects the power supply voltage Vo.

  The detector 124 detects a potential difference between both ends of the detection resistor 122. The detector 124 may be a differential amplifier that amplifies and outputs a potential difference between both ends of the detection resistor 122, for example. Since the resistance value of the detection resistor 122 is known, the power supply current can be calculated from the potential difference.

  The abnormality detection unit 126 stops the output of the power supply from the power supply unit 110 when the power supply current detected by the current detection unit 121 is larger than a predetermined threshold current. The abnormality detection unit 126 may stop the output of power supply power by inputting a stop signal to the stop terminal En of the power supply unit 110. In addition, when the output of the power supply unit 110 is stopped, the abnormality detection unit 126 preferably stops the output of the power supply unit 110 until a cancel instruction is received from a user or the like.

  With such a configuration, it is possible to prevent an excessive power supply current from flowing from the power supply unit 110. For this reason, the power supply unit 110 and the device under test 200 can be protected. Further, since the power supply apparatus 100 of this example detects the power supply voltage Vo in the vicinity of the power supply unit 110, an error occurs between the detected power supply voltage Vo and the power supply voltage Vo applied to the device under test 200. There is. Since the error depends on the impedance and the power supply current in the transmission line 120, the power supply apparatus 100 can be operated in a region where the power supply voltage error is large by stopping the operation of the power supply unit 110 when the power supply current exceeds a predetermined value. It can be prevented from operating.

  FIG. 4 is a diagram illustrating another configuration example of the power supply device 100. The power supply device 100 of this example further includes a ground wire 112, a temperature detection unit 114, and an abnormality detection unit 126 in addition to the configuration of the power supply device 100 described with reference to FIG. Other configurations may be the same as those of the power supply apparatus 100 described in relation to FIG.

  The temperature detection unit 114 detects the temperature of the power supply unit 110. The temperature detection unit 114 may detect the temperature of the ground line 112 that connects the ground terminal Gnd of the power supply unit 110 to the ground potential as the temperature of the power supply unit 110. At this time, the temperature detection unit 114 may measure the temperature of the ground wire 112 outside the power supply unit 110. Since the ground line 112 is connected to the inside of the power supply unit 110, the internal temperature of the power supply unit 110 can be estimated from the temperature of the ground line 112.

  The abnormality detection unit 126 stops the output of the power supply from the power supply unit 110 when the temperature detected by the temperature detection unit 114 is higher than a predetermined threshold temperature. Thereby, it is possible to prevent the power supply unit 110 from generating excessive heat. For example, when a failure occurs in the feedback unit 130 or the like and the output voltage of the power supply unit 110 is controlled to be excessively large, the power supply unit 110 can be stopped.

  FIG. 5 is a diagram illustrating another configuration example of the power supply device 100. The power supply device 100 of this example further includes a voltage detection unit 128 and an abnormality detection unit 126 in addition to the configuration of the power supply device 100 described with reference to FIG. Other configurations may be the same as those of the power supply apparatus 100 described in relation to FIG.

  The voltage detector 128 detects the power supply voltage Vo applied to the device under test 200. The voltage detector 128 may detect the voltage of the transmission line 120 on the device under test 200 side from the detection point where the feedback unit 130 detects the power supply voltage Vo. For example, the voltage detector 128 may detect the voltage of the transmission path 120 on the performance board on which the device under test 200 is placed. The voltage detection unit 128 may be a voltage follower that outputs a voltage corresponding to the detected power supply voltage Vo.

  The abnormality detection unit 126 stops the output of the power supply from the power supply unit 110 when the power supply voltage Vo detected by the voltage detection unit 128 is greater than a predetermined threshold voltage. Thereby, it is possible to prevent an excessive voltage from being applied to the power supply unit 110 and the device under test 200.

  In addition, the power supply apparatus 100 may be provided with the current detection unit 121, the temperature detection unit 114, and the voltage detection unit 128 described in relation to FIGS. For example, the power supply apparatus 100 may include all of these detection units, or may include any two of them. In this case, the abnormality detection unit 126 may stop the output of the power supply from the power supply unit 110 when any of the detection results in each detection unit becomes an abnormal value.

  FIG. 6 shows an example in which a plurality of power supply devices 100 are provided in parallel. A plurality of power supply apparatuses 100 of this example are provided corresponding to the plurality of devices under test 200. For example, when the same test is performed on the same type of device under test 200 in parallel, the same reference voltage is set in each power supply apparatus 100. For this reason, in this example, the voltage control unit 160 is provided in common in the plurality of power supply apparatuses 100. The voltage controller 160 may set the same digital value to the variable voltage source 136 in each power supply device 100. With such a configuration, the number of voltage control units 160 can be reduced.

  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.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

1 is a diagram showing a test system 10 according to one embodiment together with a device under test 200. FIG. 2 is a diagram illustrating a configuration example of a power supply device 100. FIG. 6 is a diagram illustrating another configuration example of the power supply device 100. FIG. 6 is a diagram illustrating another configuration example of the power supply device 100. FIG. 6 is a diagram illustrating another configuration example of the power supply device 100. FIG. An example in which a plurality of power supply devices 100 are provided in parallel is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Test system, 12 ... Test part, 14 ... Test control part, 100 ... Power supply device, 110 ... Power supply part, 112 ... Ground wire, 114 ... Temperature detection part , 120 ... transmission path, 121 ... current detection unit, 122 ... detection resistor, 124 ... detector, 126 ... abnormality detection unit, 128 ... voltage detection unit, 130 ... Feedback unit 132 ... Voltage follower circuit 134 ... Differential circuit 136 ... Variable voltage source 138, 140, 142, 144 ... Resistance 160 ... Voltage control unit 200 ..Devices under test

Claims (9)

A test system for testing a device under test,
A performance board on which the device under test is placed;
A power supply for supplying power to the device under test;
A test unit that measures predetermined characteristics of the device under test and determines the quality of the device under test, and
The power supply device
A power supply unit that is provided on the test board, generates a power supply voltage according to an input voltage applied to the input terminal, and adjusts and outputs the power supply voltage according to a control signal applied to the control terminal;
A test board provided with the power supply unit is connected to a transmission line that transmits the power supply voltage, generates the control signal according to a difference between the power supply voltage in the transmission line and a predetermined reference voltage, and the power supply unit A feedback unit that inputs to the control terminal;
A voltage control unit for controlling the reference voltage according to the power supply voltage to be supplied to the device under test;
A voltage detector for detecting the power supply voltage applied to the device under test in a transmission path on the performance board;
An abnormality detection unit for stopping output of the power supply from the power supply unit when the power supply voltage detected by the voltage detection unit is greater than a predetermined threshold voltage;
Having a test system. The power supply unit generates the power supply voltage by adjusting an on-resistance of a power amplifier that drives the input voltage as a power supply voltage based on a difference between the power supply voltage and the reference voltage. Testing system. The test system according to claim 2, wherein the power supply unit is an LDO power supply. The feedback section is
A voltage follower circuit that receives the power supply voltage output by the power supply unit and outputs substantially the same voltage as the power supply voltage;
A variable voltage source for generating the reference voltage according to control from the voltage control unit;
Wherein a voltage voltage follower circuit outputs the voltage corresponding to the difference between the reference voltage variable voltage source outputs, it claims 1-3 and a differential circuit for inputting to the control terminal of the power supply unit The test system according to any one of the above. The power supply device
A current detection unit for detecting a power supply current flowing in a transmission path for transmitting power from the power supply unit to the device under test ;
The abnormality detecting unit, said power supply current the current detection unit detects that, if greater than a predetermined threshold current, any one of the 4 claims 1 causes stopping the output of the source power from the power supply unit Test system as described in. The current detector is
In the transmission line, a detection resistor provided on the power supply unit side of a detection point where the feedback unit detects the power supply voltage;
The test system according to claim 5, further comprising: a detector that detects a potential difference between both ends of the detection resistor. The power supply device further includes a temperature detection unit that detects a temperature of the power supply unit,
The abnormality detecting unit, the temperature of the temperature detecting unit detects that, if greater than the predetermined threshold temperature, according to any one of claims 1 to 6 for stopping the output of the source power from the power supply unit Testing system. The power supply apparatus further includes a ground line that connects a ground terminal of the power supply unit to a ground potential;
The test system according to claim 7, wherein the temperature detection unit detects a temperature of the ground wire. The test apparatus includes a plurality of the power supply devices,
The test system according to any one of claims 1 to 8 , wherein the voltage control unit is provided in common in the plurality of power supply devices.

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