JPH0547876U - Self-diagnosis circuit for DC measurement unit used in IC tester - Google Patents

Abstract

(57) [Summary] [Purpose] The function of the DC measurement unit 1 is diagnosed without connecting the reference resistance unit after the output of the DC measurement unit 1. [Configuration] DC measurement unit 1 having a power supply 1A for supplying a set voltage, and DC measurement unit 1 for measuring IC3
In the IC tester including the pin switching unit 2 that connects and disconnects the terminals 11 and 12, the resistor 1E is connected between the terminals 11 and 12, and the reference resistor 1F is connected between the terminals 11 and the reference potential. Switch 1G has reference resistance 1F and terminal 1
Cut between 1 Switch 1 when testing IC3
When G is turned off, the pin switching unit 2 is turned on, and when the DC measurement unit 1 is set to the self-diagnosis mode, the switch 1G is turned on and the pin switching unit 2 is turned off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention is about a self-diagnosis circuit of a DC measurement unit used in an IC tester.

The DC measurement unit of the IC tester includes a voltage applied current measuring function for measuring a current flowing in a load by applying a reference program voltage, and a current applied voltage measuring a voltage generated in the load by adding a reference program current. There is a measurement function. The IC tester is provided with a self-diagnosis circuit that determines whether the function of the DC measurement unit operates normally.

[0003]

[Prior Art]

 Next, the configuration of the DC measurement unit of the IC tester according to the prior art will be described with reference to FIG. 2A is a power supply, 1B is an amplifier, 1C is an ammeter, 1D is an amplifier, 2 is a pin switching unit, 3 is an IC to be measured, and 4 is a reference resistance unit. The DC measurement unit 10 is composed of 1A to 1D in FIG. 2, 11 is a terminal for voltage supply, and 12 is a terminal for feedback to a set voltage.

Next, the operation of FIG. 2 will be described. The set voltage of the power source 1A is supplied from the terminal 11 to the pin switching unit 2 and applied to the IC 3 by the switch of the pin switching unit 2. In FIG. 2, the switches 2A, 2B, 2C and 2D are brought into contact with each other to apply the set voltage of the power source 1A to the IC 3. Feedback is applied from the terminal 12 to the amplifier 1B through the amplifier 1D so that the power source 1A supplies a stable voltage to the IC3. In the self-diagnosis state of the DC measurement unit 10, the switches 2A, 2C, 2E, and 2F of the pin switching unit 2 are connected to connect the terminals 11 and 12 to the reference resistance unit 4.

For example, assuming that the set voltage of the power source 1A is Vf, the resistance value of the resistor 4B of the reference resistance unit 4 is Rm, and the measured current value is If, if If = Vf / Rm, FIG. 2 is operating normally. Can be diagnosed.

[0006]

[Problems to be solved by the device]

 Since the reference resistance unit 4 in FIG. 2 is usually one set per IC tester, it is necessary to perform self-diagnosis for each DC measurement unit 10, and in an IC tester with a large number of units, the time required for self-diagnosis increases. To do. Further, the function check of the DC measurement unit 10 requires external circuits of the pin switching unit 2 and the reference resistance unit 4, but if these external circuits fail, it is difficult to identify the defective portion.

According to this invention, a resistor 1E is connected between terminals 11 and 12 of a DC measuring unit 10, a reference resistor 1F is connected between a terminal 11 and a reference potential, and a reference resistor 1F and a terminal 11 are connected. The purpose of the present invention is to provide a self-diagnosis circuit for the DC measurement unit, which can diagnose the function of the DC measurement unit without connecting the reference resistance unit after the output of the DC measurement unit by connecting the switch 1G between them. To do.

[0008]

[Means for Solving the Problems]

 In order to achieve this object, in the present invention, a DC power supply unit 1A for supplying a set voltage, a terminal 11 for supplying the set voltage, and a DC measurement unit 1 having a terminal 12 for feedback to the set voltage, In an IC tester equipped with a pin switching unit 2 for connecting and disconnecting the terminal 11 and the terminal 12 to an IC 3 to be connected, a resistor 1E connected between the terminal 11 and the terminal 12 and a resistor 1E connected between the terminal 11 and the reference potential. The DC measurement unit 1 is provided with a reference resistance 1F and a switch 1G for connecting and disconnecting the reference resistance 1F and the terminal 11. When testing the IC3, the switch 1G is cut off and the pin switching unit 2 is connected for DC measurement. When the unit 1 is set to the self-diagnosis mode, the switch 1G is turned on and the pin switching unit 2 is turned off.

[0009]

[Action]

 Next, the configuration of the self-diagnosis circuit of the DC measurement unit according to the present invention will be described with reference to FIG. Reference numeral 1 in FIG. 1 is a DC measurement unit, and FIG. 1 is obtained by removing the reference resistance unit 4 in FIG. 2 and adding a resistance 1E, a reference resistance 1F, and a switch 1G to the DC measurement unit 1. The resistor 1E is connected between the terminals 11 and 12, and the reference resistor 1F is connected between the terminal 11 and the reference potential. The switch 1G connects and disconnects between the reference resistor 1F and the terminal 11.

Next, the operation of FIG. 1 will be described. When testing the IC3, the switch 1G is turned off and the pin control relays 2A, 2B, 2C and 2D of the pin switching unit 2 are connected. As a result, the set voltage of the power supply 1A is supplied from the DC measurement unit 1 to the pin of the IC3.

When the DC measuring unit 1 is to be self-diagnosed, the switch 1G is turned on and the relays 2A, 2B, 2C, 2D of the pin switching unit 2 are turned off. As a result, the reference resistance 1F is connected as a load to the terminal 11 of the DC measurement unit 1, and the terminal 12 has the same potential as the terminal 11 through the resistance 1E.

In the case of self-diagnosis of the voltage applied current measurement function, the voltage Vf is supplied from the power supply 1A to the terminal 11. As a result, the current If flows through the resistor 1F having the resistance value Rm. The current If = Vf / Rm at this time is the expected value. If the value of the current If is measured by the ammeter 1C in the DC measurement unit 1 and compared with the expected value obtained by the calculation formula, the quality of the DC measurement unit 1 can be determined. At this time, the resistor 1E is necessary for feedback so that the voltage Vf is stably output to the terminal 11.

[0013]

[Effect of the device]

 According to this invention, the resistor 1E is connected between the terminal 11 and the terminal 12, the reference resistor 1F is connected between the terminal 11 and the reference potential, and the reference resistor 1F and the terminal 11 are disconnected by the switch 1G. Therefore, the self-diagnosis can be performed only with the DC measurement unit. Therefore, an external circuit becomes unnecessary, and it becomes easy to identify a defective portion when a defect occurs.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a self-diagnosis circuit of a DC measurement unit according to the present invention.

FIG. 2 is a configuration diagram of a self-diagnosis circuit of a DC measurement unit according to a conventional technique.

[Explanation of symbols]

 1 DC measuring unit 1A power supply 1B amplifier 1C ammeter 1D amplifier 1E resistance 1F reference resistance 1G switch 2 pin switching unit 11 voltage supply terminal 12 voltage feedback terminal

Claims (1)

[Scope of utility model registration request] 1. A DC measuring unit having a power supply (1A) for supplying a set voltage, a first terminal (11) for supplying the set voltage, and a second terminal (12) for feedback to the set voltage.
(1) and the IC (3) to be measured has a first terminal (11) and a second terminal (12)
In a IC tester including a pin switching unit (2) for connecting and disconnecting, a resistor connected between the first terminal (11) and the second terminal (12).
(1E) and a reference resistor (1
F), a switch that connects and disconnects between the reference resistance (1F) and the first terminal (11)
(1F) is installed in the DC measurement unit (1), when testing the IC (3), switch (1G) is turned off, the pin switching unit (2) is connected, and the DC measurement unit (1) is self-diagnosed. A self-diagnosis circuit for a DC measuring unit used in an IC tester, which is characterized by turning on the switch (1G) and turning off the pin switching unit (2) when switching to the mode.