JP2876844B2 - Output voltage correction circuit for IC tester driver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output voltage correction circuit for making an output voltage of an IC tester driver equal to a set voltage.

[0002]

2. Description of the Related Art Next, the configuration of a conventional driver output voltage correction circuit will be described with reference to FIG. 1 and 2 in FIG.
Is an amplifier, 3 is a driver, 31 and 32 are variable resistors for correcting the output level of the driver 3, 4 is a switch, and 5 is a voltage measuring device.

In FIG. 2, 1A is the input terminal of the amplifier 1, 2A is the input terminal of the amplifier 2, 3A is the input terminal of the driver 3, 3
B is an output terminal of the driver 3, and 3C and 3D are input terminals of the driver. When the input terminal 3A has positive logic, the voltage of the input terminal 3C is output to the output terminal 3B of the driver 3,
When the input terminal 3A has a negative logic, the output terminal 3
The voltage at the input terminal 3D is output to B.

When the input terminal 3A has a positive logic, the driver 3
The output terminal 3B of the driver 3 and the output terminal 3B of the driver 3 when the input terminal 3A has a negative logic include an offset error and a gain error, respectively. Therefore, the offset error of the output terminal 3B of the driver 3 when the input terminal 3A has the positive logic is corrected by the variable resistor 31, and the offset error of the output terminal 3B of the driver 3 when the input terminal 3A has the negative logic is changed by the variable resistor. The correction is performed by the detector 32. When the switch 4 is turned on, the voltage of the output terminal 3B is measured by the voltmeter 5. In the IC tester, the voltages of the input terminal 1A and the input terminal 2A are programmable, and various voltages are set within several hundred ms, so that the gain error is not corrected.

For example, when 5 V is applied to the input terminal 1A when the input terminal 3A is positive logic, the voltage of the output terminal 3B becomes 5V.
However, in practice, the voltage of the output terminal 3B becomes 4.98 V or the like due to the offset error and the gain error. When the input terminal 3A is negative logic, -5V is applied to the input terminal 2A.
Is added, the voltage of the output terminal 3B should be -5V. However, the voltage of the output terminal 3B becomes -4.98V or the like due to an offset error and a gain error. Similarly,
When 0V is applied to the input terminal 1A when the input terminal 3A is in positive logic, the voltage of the output terminal 3B should be 0V.
Actually, it becomes -0.02 V, and when 0 V is applied to the input terminal 2A when the input terminal 3A has a negative logic, the output terminal 3B
Should be 0V, but actually +0.02
V and so on.

[0006]

In FIG. 2, the driver 3
Is corrected by the variable resistor 31 or the variable resistor 32, the correction cannot be performed in a short time, and the gain error is not corrected. According to the present invention, a feedback resistor is connected to each of the amplifiers 1 and 2, and a correction current is supplied to the feedback resistors to correct the output voltages of the amplifiers 1 and 2, thereby correcting the output voltage of the driver 3 and the voltage of the terminal 3B. Is the voltage of the input terminal 1A or the voltage of the input terminal 2A.

[0007]

In order to achieve this object, according to the present invention, an amplifier 1 in which a voltage applied to an input terminal 1A is amplified and a feedback resistor 11 is connected between the input terminal 1B and an output is provided. , Amplifying the voltage applied to the input terminal 2A, the amplifier 2 having a feedback resistor 12 connected between the input terminal 2B and the output, the output of the amplifier 1 being applied to the input terminal 3C, and the output of the amplifier 2 being the input terminal. 3D, when the positive logic is applied to the input terminal 3A, the voltage of the input terminal 3C is output to the output terminal 3B, and when the negative logic is applied to the input terminal 3A, the voltage of the input terminal 3D is changed to the output terminal. 3B, a current output type D / A converter 6 for controlling the current flowing through the feedback resistor 11 of the amplifier 1 to control the current flowing through the feedback resistor 11 of the amplifier 1, and flowing through the feedback resistor 12 of the amplifier 2 Control the current and amplifier A D / A converter 7 of the current output type for controlling the output voltage of, controls the configuration of the input 7A of the input 6A or D / A converter 7 of the D / A converter 6, the driver 3
Control means 8 for making the voltage at the output terminal 3B equal to the voltage at the input terminal 1A or the voltage at the input terminal 2A, the input 6A of the D / A converter 6 at the time of offset error correction and the D / A converter 7
Of the input 7A, the input 6A of the D / A converter 6 and the input 7A of the D / A converter 7 when the gain error is corrected.
And a storage device 9 for storing the final set value 22 of the above.

[0008]

Next, the configuration of the output voltage correction circuit of the IC tester driver according to the present invention will be described with reference to FIG. In FIG. 1, 6 and 7 are current output type D / A converters, 8 is control means, 9
Is a storage device, 11 is a feedback resistor connected between the output of the amplifier 1 and the input terminal 1B, 12 is a feedback resistor connected between the output of the amplifier 2 and the input terminal 2B, and the others are the same as those in FIG. is there.

The voltage applied to the input terminal 1A of the amplifier 1 is added to the voltage of the product of the output current of the D / A converter 6 and the feedback resistor 11, and is added to the input terminal 3C of the driver 3. Output terminal 3B when input 3A of
Is output to The control means 8 controls the output terminal 3 of the driver 3
B so that the voltage measured by the voltmeter 5 through the switch 4 is equal to the voltage applied to the input terminal 1A.
The set value of the input 6A of the D / A converter 6 is determined while changing the input 6A of the / A converter 6, and correction is performed.

Next, a specific correction procedure will be described. First
In the stage, a voltage is applied to the input terminal 1A, and an initial value is set to the input 6A. In the second stage, the voltage of the driver output terminal 3B is measured. In the third stage, the voltages of the input terminal 1A and the output terminal 3B are compared. If they are not equal, the process proceeds to the fourth stage. When the voltages of the input terminal 1A and the output terminal 3B become equal, the correction is completed. . In the fourth stage, input 6A
Is increased or decreased, the input 6A is reset, and the process returns to the third stage.

When the voltage at the input terminal 1A is 0 V, the final set value 21 of the input 6A of the D / A converter 6 is determined.
Is stored in the storage device 9 as a set value at the time of offset error correction, and the set value 22 of the input 6A of the D / A converter 6 which is finally determined when the voltage of the input terminal 1A is, for example, 5V
Is stored in the storage device 9 as a set value at the time of gain error correction.

Next, when a voltage in the range of 0 to 5 V is applied to the input terminal 1A, the set value 23 of the input 6A becomes the set value 21 for the offset error correction of the storage device 9 and the set value 21 for the gain error correction. The voltage at the output terminal 3B can be made the same as the voltage at the input terminal 1A by calculating the control unit 8 by regarding the two points of the value 22 as linear approximation. Similarly, the input terminal 2A corrects the voltage of the driver 3.

[0013]

According to the present invention, a feedback resistor is connected to each of the two amplifiers, and a correction current is supplied to the feedback resistors.
Since the output voltage of the driver is corrected by correcting the output voltages of the amplifiers, the voltage of the output terminal can be made equal to the voltage of the input terminal 1A or the voltage of the input terminal 2A. Further, since the control means and the storage device are used, it is possible to correct all the settings of the programmable output voltage.

[Brief description of the drawings]

FIG. 1 is an output voltage correction circuit of an IC tester driver according to the present invention.

FIG. 2 is an output voltage correction circuit of a conventional IC tester driver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Amplifier 2 Amplifier 3 Driver 4 Switch 5 Voltage measuring device 6 D / A converter 7 D / A converter 8 Control means 9 Storage device

Claims (2)

(57) [Claims] A first amplifier (1) which amplifies a voltage applied to a first input terminal (1A) and has a feedback resistor (11) connected between a second input terminal (1B) and an output. Amplifying the voltage applied to the third input terminal (2A), and connecting the feedback resistor (12) between the fourth input terminal (2B) and the output.
The output of the first amplifier (1) is applied to a fifth input terminal (3C), and the output of the second amplifier (2) is applied to a sixth input terminal (3D). When positive logic is applied to the seventh input terminal (3A), the voltage of the fifth input terminal (3C) is output to the output terminal (3B), and negative logic is applied to the seventh input terminal (3A). When the voltage is applied, the voltage of the sixth input terminal (3D) is output to the output terminal (3B), and the current flowing to the feedback resistor (11) of the first amplifier (1) is controlled. ,
A current output type first D / A converter (6) for controlling the output voltage of the first amplifier (1) and a current flowing to the feedback resistor (12) of the second amplifier (2);
A current output type second D / A converter (7) for controlling the output voltage of the second amplifier (2); and an input (6A) or a second input / output of the first D / A converter (6). The setting of the input (7A) of the D / A converter (7) is controlled, and the voltage of the output terminal (3B) of the driver (3) is changed to the voltage of the first input terminal (1A) or the third terminal.
A control means (8) for making the voltage equal to the voltage of the input terminal (2A) of the IC tester. 2. A first amplifier (1) in which a voltage applied to a first input terminal (1A) is amplified, and a feedback resistor (11) is connected between the second input terminal (1B) and an output. Amplifying the voltage applied to the third input terminal (2A), and connecting the feedback resistor (12) between the fourth input terminal (2B) and the output.
The output of the first amplifier (1) is applied to a fifth input terminal (3C), and the output of the second amplifier (2) is applied to a sixth input terminal (3D). When positive logic is applied to the seventh input terminal (3A), the voltage of the fifth input terminal (3C) is output to the output terminal (3B), and negative logic is applied to the seventh input terminal (3A). When the voltage is applied, the voltage of the sixth input terminal (3D) is output to the output terminal (3B), and the current flowing to the feedback resistor (11) of the first amplifier (1) is controlled. ,
A current output type first D / A converter (6) for controlling the output voltage of the first amplifier (1) and a current flowing to the feedback resistor (12) of the second amplifier (2);
A current output type second D / A converter (7) for controlling the output voltage of the second amplifier (2); and an input (6A) or a second input / output of the first D / A converter (6). The setting of the input (7A) of the D / A converter (7) is controlled, and the voltage of the output terminal (3B) of the driver (3) is changed to the voltage of the first input terminal (1A) or the third terminal.
Control means (8) for making the voltage equal to the voltage at the input terminal (2A) of the first D / A converter (6) at the time of offset error correction
(6A) and the final setting value of the input (7A) of the second D / A converter (7)
(21), the final setting value (22) of the input (6A) of the first D / A converter (6) and the input (7A) of the second D / A converter (7) at the time of gain error correction An output voltage correction circuit for an IC tester driver, comprising: a storage device (9) for storing the following.