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Timestamp: 2020-01-27 22:46:57
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Matched Legal Cases: ['art.\n7', 'art.\n8', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16', 'art 16']

Pin electronics having current measuring unit and testing apparatus having pin electronics thereof - Advantest Corporation
United States Patent 6498473
Yamabe, Masahiko (Tokyo, JP)
09/677784
G01R31/28; G01R31/30; G01R31/319; G06F11/00; (IPC1-7): G06F11/00
714/736, 326/90, 326/30, 324/158.1, 324/512-513, 714/724, 326/62, 324/765, 324/551, 324/763, 324/73.1
Download PDF 6498473 PDF help
6275023 Semiconductor device tester and method for testing semiconductor device 2001-08-14 Oosaki et al. 324/158.1
6133725 Compensating for the effects of round-trip delay in automatic test equipment 2000-10-17 Bowhers 324/158.1
5200696 Test system apparatus with Schottky diodes with programmable voltages 1993-04-06 Menis et al. 324/73.1
4523312 IC tester 1985-06-11 Takeuchi 714/736
1. A pin electronics, which inputs and outputs signal from and to an input/output pin of an electric part, provided in a testing apparatus that tests said electric part; comprising: a current source which outputs desired electric current; a first voltage generator which generates a desired voltage; and a diode bridge, which is connected to each of said current source, said first voltage generator, and said input/output pin of said electric part, that provides said desired electric current to said electric part and provides said desired voltage to said electric part; wherein: said first voltage generator has a current measuring unit that measures an electric current, which is input from said first voltage generator to said diode bridge; and said first voltage generator being connected to one terminal of said diode bridge that is different than a terminal to which said input/output pin of said electric part is connected.
2. A pin electronics as claimed in claim 1, wherein: said current source has a first current source that outputs said desired electric current to said diode bridge and a second current source that inputs said desired electric current from said diode bridge; and said pin electronics further comprising: a control unit that controls said first current source to output a predetermined electric current and controls said second current source to input said predetermined electric current from said diode bridge when measuring an electric current, which is input to said electric part, by applying a predetermined voltage on said input/output pin.
4. A pin electronics as claimed in claim 2, further comprising: a clamp unit that compensates for an output value of said electric part; and a comparator, which judges an output voltage output from said electric part; wherein: said clamp unit includes: a second voltage generator which generates a voltage to be provided to said electric part; a current generator which generates desired current; a switch that connects or disconnects said current generator to said electric part; and said control unit controls said switch to connect said current generator to said electric part to provide said desired electric current to said electric part and controls said comparator to judge said output voltage when measuring said output voltage by applying said desired electric current on said electric part.
7. A pin electronics, which inputs and outputs signal from and to an input/output pin of an electric part, provided in a testing apparatus that tests said electric part; comprising: a clamp unit which compensates for an output value of said electric part; wherein: said clamp unit includes: a voltage generator which generates a voltage to be provided to said electric part; a current generator which generates desired current; a switch that connects or disconnects said current generator to said electric part; and said pin electronics further comprising: a comparator, which judges an output voltage output from said electric part; and a control unit that controls said switch to connect said current generator to said electric part to provide said desired electric current to said electric part and controls said comparator to judge said output voltage when measuring said output voltage by applying said desired electric current on said electric part.
8. A testing apparatus for testing whether an electric part is normal or not, comprising: a pattern generator that generates a test pattern to be applied to said electric part and an expectation value, which is to be output when said electric part is normal; a pin electronics that outputs said test pattern to said electric part and inputs an output value of said electric part; a comparison unit that compares said expectation value and said output value, which is provided via said pin electronics, and judges whether said electronic part is normal or not; wherein: said pin electronics has: a current source that outputs desired current; a voltage generator that generates desired voltage; and a diode bridge, which is connected to each of said current source, said voltage generator, and said input/output pin of said electric part, that provides said desired electric current to said electric part and provides said desired voltage to said electric part; said voltage generator has a current measuring unit that measures an electric current, which is input from said voltage generator to said diode bridge; and said first voltage generator being connected to one of terminals of said diode bridge that is different than said terminal to which said input/output pin of said electric part is connected.
9. A testing apparatus for testing whether an electric part is normal or not, comprising: a pattern generator that generates a test pattern to be applied to said electric part and an expectation value to be output when said electric part is normal; a pin electronics that outputs said test pattern to said electric part and inputs an output value of said electric part; a comparison unit that compares said expectation value and said output value, which is provided via said pin electronics, and judges whether said electronic part is normal or not; wherein: said pin electronics has: a clamp unit which compensates for an output value of said electric part; and a comparator, which judges an output voltage output from said electric part; wherein: said clamp unit includes: a voltage generator which generates a voltage to be provided to said electric part; a current generator which generates a desired current; a switch that connects or disconnects said current generator to said electric part; and said testing apparatus further comprising a control unit that controls said switch to connect said current generator to said electric part to provide said desired electric current to said electric part and controls said comparator to judge said output voltage when measuring said output voltage by applying said desired electric current on said electric part.
The judging unit 22 has a reference voltage source 23a, a reference voltage source 23b, a comparator 22a, and a comparator 22b. The reference voltage source 23a generates a first reference voltage used for judging a high level electric potential. The reference voltage source 23b generates a second reference voltage used for judging a low level electric potential. The comparator 22a compares an output voltage of the electronic part 16 and the first reference voltage. The comparator 22b compares an output voltage of the electronic part 16 and the second reference voltage. The programmable load 25 has a voltage generator 21, which generates a desired voltage, and a current measuring unit 27 which measures an electric current.
FIG. 4 shows an embodiment of the clamp unit 54. The clamp unit 54 has a first clamp unit 54a and a second clamp unit 54b. The first clamp unit 54a has a first dynamic clamp unit 90a, a switch 65, and a voltage source P1 and P2. The first dynamic clamp unit 90a has operational amplifiers 72 and 74, switches 66 and 70, and a D/A convertor 80. The second clamp unit 54b has a second dynamic clamp unit 90b, a switch 67, and voltage sources P3 and P4. The second dynamic clamp unit 90b has operational amplifiers 76 and 78, switches 68 and 69, and a D/A convertor 82.
If the voltage at the input/output pin of the electronic part 16 is lower than the minimum allowable input voltage of the driver 20, the judging unit 22, and the programmable load 25, the first clamp unit 54a outputs a first voltage to the electronic part 16 so that the voltage at the input/output pin of the electronic part 16 does not become lower than the minimum allowable voltage. If the voltage at the input/output pin of the electronic part 16 is higher than the maximum allowable input voltage, the second clamp unit 54b provides a second voltage to the electronic part 16 so that the voltage at the input/output pin of the electronic part 16 does not become higher than the maximum allowable input voltage.
The configuration of the clamp unit 54 will be explained below. The capacitor C2 is provided to the first clamp unit 54a for reducing the fluctuation of the voltage in the first clamp unit 54a. The voltage source P2 generates the first voltage. For example, the first voltage is preferably a voltage higher than the minimum allowable input voltage of the driver 20, the judging unit 22, and the programmable load 25. Because the first clamp unit 54a outputs an electric current when the voltage at the input/output pin of the electronic part 16 is lower than the first voltage, the first clamp unit 54a can make the voltage at the input/output pin of the electronic part 16 higher than the first voltage.
When the first dynamic clamp unit 90a is used to compensate for the distortion of the output value of the electronic part 16 caused by the difference between the impedance in the transmission path and the output impedance of the electronic part 16, the switches 65 and 66 are closed, and the switch 70 is opened. When performing the current applying voltage measuring test, the switches 65 and 70 are closed, and the switch 66 is opened. If the switch 70 is closed, a current generator, which has the D/A convertor 80, the operational amplifier 72 and 74 and resistors R7, R8, R9, R10, R11, R12, and R13, is formed. The D/A convertor 80 outputs a predetermined voltage to the inverse input terminal of the operational amplifier 74.
In the case of performing the current applying voltage measuring test, the first clamp unit 54a applies a positive electric current to the electronic part 16, and the second clamp unit 54b applies a negative electric current to the electronic part 16. The functions and the operation of the second clamp unit 54b can be easily understood by those skilled in the art based on the function and the operation of the first clamp unit 54a, therefore the explanation will be abbreviated.
If the first clamp unit 54a applies an electric current to the electronic part 16, the second clamp unit 54b does not apply an electric current to the electronic part 16. Furthermore, if the second clamp unit 54b applies an electric current to the electronic part 16, the first clamp unit 54a does not apply an electric current to the electronic part 16. For example, when the switches 70 and 65 are closed, the switch 69 is opened. Moreover, the opening and closing operation of the switches 65, 66, 67, 68, 69, and 70 is preferably controlled by the control unit 51, not shown in FIG. 4. In the other embodiment, the opening and closing operation of the switches 65, 66, 67, 68, 69, and 70 may be controlled by the controller 17. For example, the control unit 51 can be a logic or a CPU, which is controlled by a program.
FIG. 5 shows a comparator 22a and a reference voltage source 23a included in a judging unit 22. The voltage at the input/output pin of the electronic part 16 when a constant current is applied to the input/output pin of the electronic part 16 during performing the current applying voltage measuring test, is input to the comparator 22a. The reference voltage source changes a reference voltage one after another and outputs the reference voltage to the comparator 22a based on the signal output from the controller 17. The comparator 22a compares the voltage at the input/output pin provided from the electronic part 16 and the reference voltage provided from the reference voltage source 23a. Therefore, the judging unit 22 can judge the voltage at the input/output pin of the electronic part 16 by judging whether the voltage at the input/output pin of the electronic part 16 matches the reference voltage.
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