JP2000214222A - Power supply circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly reliable power supply circuit by controlling the boost amplifier of a plurality of slave power supply circuits with a control amplifier of a master power supply circuit. SOLUTION: A voltage Vin for instructing for an output voltage is inputted to a control amplifier OP1 via a resistor R1, and the output is connected to the input of boost amplifiers AMP1 and AMP2. The output of both of them is commonly connected at a common connection point B via each current detection means, and its output Vout is supplied to a target DUT to be tested. Also, a buffer amplifier OP2 for sensing and a resistor R2 form the feedback path of the output voltage Vout, and the output voltage Vout is fed back to the input of the control amplifier OP1 via the feedback path. Then, since the parallel connection of the negative feedback path that has been a problem is eliminated and the boost amplifier AMP2 of a slave power supply circuit 60 is dependent on the control amplifier OP1 of a master power supply circuit 50, the power supply circuit indicates the similar characteristics to the operation by a simple- substance power supply circuit and can be operated stably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device used for a test device of a semiconductor integrated circuit (LSI), and more particularly, to a power supply circuit having a plurality of power supply circuits having the same configuration connected in parallel.
The present invention relates to a power supply device that secures a current capacity required by I (DUT: Device Under Test), and more particularly to a power supply circuit capable of suitably performing parallel driving.

[0002]

2. Description of the Related Art Conventionally, in an LSI test apparatus, a DU
In order to apply a specified voltage to each terminal of T, a dedicated power supply is individually used for each DUT. However, DUTs that require a large supply current have appeared along with the high integration of LSIs. In this case, a method is used in which the individual power supplies are driven in parallel to satisfy the current capacity required by the DUT. FIG. 4 is a configuration diagram showing an example in which two power supply circuits are driven in parallel according to such a method.

[0003] In FIG. 4, resistors R 1, R 2, R 3, amplifiers OP 1, OP 2, AMP 1 and current detection means U 1 constitute a first power supply circuit 10. In this power supply circuit 10, a voltage Vin indicating an output voltage is input to a control amplifier OP1 via a resistor R1, and the output of the control amplifier OP1 is a boost amplifier AMP1 that amplifies the output of the control amplifier by current and voltage. Connected to the input of The output of the boost amplifier AMP1 is input to current detection means constituted by the resistor R3 and the current detection circuit U1, and the output of this current detection means is output to the DUT as the output voltage Vout. The sense buffer amplifier OP2 and the resistor R2 form a feedback path for the output voltage Vout, and the output voltage Vout
out is connected to the control amplifier OP1 via this feedback path.
Is fed back to the input.

[0004] With a configuration similar to the above, resistors R4, R4
5, R6, amplifiers OP3, OP4, AMP2, and current detecting means U2 constitute a second power supply circuit 20.

[0005] The outputs of these two power supply circuits are commonly connected at a common connection point B and used as one power supply circuit. By driving a plurality of power supply circuits in parallel in this manner, a power supply circuit having a large current capacity can be realized.

[0006]

However, when the individual power supplies are simply connected in parallel as in the conventional power supply circuit described with reference to FIG. 4, the feedback system is disturbed and the transient response is deteriorated. There is a problem that current balance is lost. Therefore, a method of inserting diodes D1 and D2 into the output of each power supply circuit as in the circuit shown in FIG. 5 has been used.

However, even in the power supply circuit configured as shown in FIG. 5, there is a problem that an error occurs in the output voltage of each power supply circuit due to variation in the characteristics of the diodes D1 and D2. Further, in both the power supply circuits of FIG. 4 and FIG. 5, there is also a problem that the current value obtained by the current detection means of each power supply circuit must be added when calculating the current consumption of the DUT. Further, each power supply circuit connected in parallel constitutes a negative feedback loop. However, since these negative feedback loops use the same point as a feedback point, it is difficult to obtain a stable response. Therefore,
In dynamic characteristics in which current consumption suddenly changes due to a sudden change in load or the like, there is a problem that unstable operation such as overshoot may occur due to variations in characteristics of each power supply circuit.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, can operate stably even with dynamic characteristics, eliminates errors caused by diodes and inconvenience in measuring current consumption, and provides a plurality of power supply circuits. It is an object of the present invention to provide a power supply circuit for parallel driving which has the same stability as a single power supply circuit even when the power supplies are driven in parallel.

[0009]

According to the first aspect of the present invention, there is provided a power supply circuit for parallel driving, comprising: a signal input terminal to which a signal indicating an output voltage is input; A control amplifier for amplifying a voltage signal input from the input terminal, a boost amplifier for current amplification and voltage amplification of an output signal of the control amplifier, current detection means for detecting an output current of the boost amplifier, Feedback means for feeding back the output voltage of the boost amplifier to the input terminal of the control amplifier, control signal output means for supplying the output signal of the control amplifier to another power supply circuit, and controlling the boost amplifier to control another power supply circuit Control signal input means for inputting a signal; inputting an output signal of a control amplifier of one master power supply circuit to boost amplifiers of a plurality of slave power supply circuits; It is characterized in that constructed several power supply circuit to the parallel drive.

Thus, the boost amplifiers of the plurality of slave power supply circuits can be controlled by the control amplifiers of the master power supply circuit.

According to a second aspect of the present invention, in the first aspect of the present invention, the plurality of power supply circuits each include a control signal output unit and a control signal input unit, and each of the plurality of power supply circuits has the same configuration as a master circuit. The power supply circuit and the slave power supply circuit can be diverted.

This makes it possible to use one power supply circuit as both a master power supply circuit and a slave power supply circuit.

According to a third aspect of the present invention, in the first aspect of the present invention, the slave power supply circuit is configured such that the number of parallel connections can be freely changed according to a current capacity required by a device to be inspected. It is characterized by having been done.

Thus, the power supply circuit is connected to the DUT to be measured.
It is possible to freely adjust the current capacity according to the current capacity required by (1).

According to a fourth aspect of the present invention, in the first aspect of the invention, the control signal output means and the control signal input means are configured using a general-purpose semiconductor switch circuit. Things.

Thus, the control signal output means and the control signal input means can be realized with a simple circuit configuration.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the consumption current of the object to be inspected is a current value obtained by current detection means of the slave power supply circuit. It is characterized in that it is configured to obtain a value by multiplying the number.

Thus, the current consumption of the DUT to be inspected can be easily obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a circuit diagram showing one embodiment of a power supply device according to the present invention. FIG. 1 is a configuration diagram in the case where two power supply circuits are driven in parallel by using the power supply circuit 50 as a master power supply circuit and the power supply circuit 60 as a slave power supply circuit. In the figure, the same components as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 1, the difference from the conventional example is that the master power supply circuit 50 is provided with control signal output means SW1, the slave power supply circuit 60 is provided with control signal input means SW2,
The point is that these are connected by the signal line L. Here, a semiconductor switch circuit is used for the SW1 and SW2, and the SW1 is turned on and the SW2 is turned off. As a result, the output of the control amplifier OP3 of the slave power supply circuit 60 is disconnected from the input of the boost amplifier AMP2, and the output of the control amplifier OP1 of the master power supply circuit 50 is changed to the boost amplifier AMP1 of the master power supply circuit 50.
Is output to the input of the boost amplifier AMP2 of the slave power supply circuit 60. FIG. 2 is a circuit diagram schematically showing a circuit connected in this manner.

In FIG. 2, a voltage V indicating an output voltage is shown.
In is input to the control amplifier OP1 via the resistor R1, and the output of the control amplifier OP1 is connected to the inputs of the boost amplifiers AMP1 and AMP2. The outputs of the boost amplifiers AMP1 and AMP2 are commonly connected at a common connection point B via respective current detection means, and the output V
out is supplied to the DUT under test. The sense buffer amplifier OP2 and the resistor R2 are connected to the output voltage Vout.
And the output voltage Vout is fed back to the input of the control amplifier OP1 via this feedback path.

2, the parallel connection of the negative feedback path, which is a problem in the prior art, is eliminated, and the boost amplifier AMP2 of the slave power supply circuit 60 is replaced with the control amplifier OP1 of the master power supply circuit 50. It turns out that it is dependent on. Since the number of the negative feedback paths is one, the power supply circuit shown in FIG. 11 exhibits the same characteristics as the case of operating with a single power supply circuit, and can operate stably. Further, when the setting of the output voltage or the like is changed, the setting of the entire power supply circuit can be changed only by changing the master power supply circuit 50 alone.

As can be seen from comparison with FIG. 4 shown in the conventional example, in the power supply circuit of FIG. 1, the parallel connection portion is connected from the output (point A) of the control amplifier OP1 to the common connection point (B
Up to the point), which shows that the influence on the output current balance of the other circuit portions is eliminated.

Here, the boost amplifiers AMP1 and AMP
The gain of the control amplifier O
The output potential of P1 is V1, the output potential of boost amplifier AMP1 is V2, and the output potential of boost amplifier AMP2 is V3.
Then, the following holds: V1 × n = V2 = V3 (1), and the boost amplifier and AMP1 and AMP2 output voltages of the same potential. The resistors R3 and R6 are current detecting resistors and operate in parallel in the same current range.
= R6. At this time, the output voltage of this power supply circuit is Vo
ut, the output current I1 of the boost amplifier AMP1 and the output current I2 of the boost amplifier AMP2 satisfy I1 = (V2-Vout) / R3 = (V3-Vout) / R6 = I2. As described above, the outputs of the boost amplifiers AMP1 and AMP2 output Iout / 2, respectively, assuming that the current required by the DUT to be inspected is Iout. Similarly, when n slave power supply circuits are driven in parallel, each slave power supply circuit
ut / n.

Therefore, the boost amplifiers AMP1 and AMP
The current balance of each power supply circuit can be easily achieved by adjusting the offset and gain of 2 and adjusting the variation of the resistance value from the output of the boost amplifier to the common connection point B. If these are adjusted according to the accuracy of the required current measurement, the current consumption of one power supply circuit can be measured by multiplying this value by the number of power supply circuits driven in parallel. It is possible.

Although the control signal output means and the control signal input means are briefly described in the power supply circuit of FIG. 1 for simplicity, the actual power supply circuit has a configuration as shown in FIG. . That is, when the power supply circuit 70 is used as a master power supply circuit and the power supply circuit 80 is used as a slave power supply circuit to drive them in parallel, the switches SW11, SW12, SW1
6 is turned on, and switches SW13, SW14, SW15
Is turned off. Conversely, when the power supply circuit 80 is a master power supply circuit and the power supply circuit 70 is a slave power supply circuit, the switches SW13, SW14, and SW15 are turned on, and the switches SW11, SW12, and SW16 are turned off.

As described above, by configuring the control signal output means and the control signal input means as shown in FIG. 3, one power supply circuit can be used as both a master power supply circuit and a slave power supply circuit. It becomes possible.

It should be noted that the foregoing description has been directed to specific preferred embodiments for the purpose of illustration and illustration of the invention. Therefore, the present invention is not limited to the above-described embodiments, and includes many more modifications without departing from the spirit thereof.
This includes deformation.

[0029]

As is apparent from the above description,
According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, the power supply circuit according to the present invention is configured such that the control amplifier of the master power supply circuit controls the boost amplifiers of the plurality of slave power supply circuits. Since only the amplifier section is provided and only one feedback path is provided, it is possible to perform the same stable operation as when a single power supply circuit is driven. Further, since the setting change of the output voltage and the like is performed for the master power supply circuit, the setting change is easy when a large number of slave power supply circuits are used in parallel.

According to the invention described in claim 2, in the invention described in claim 1, the power supply circuit can use one power supply circuit as both a master power supply circuit and a slave power supply circuit. Thus, it is possible to effectively utilize the hardware of the semiconductor test device.

According to a third aspect of the present invention, in the first aspect of the present invention, the slave power supply circuit can freely change the number of parallel connections according to a current capacity required by a device under test. With this configuration, it is possible to finely correspond to the current capacity required by the DUT to be measured.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the control signal output means and the control signal input means are constituted by using a general-purpose semiconductor switch circuit. Circuits can be manufactured in a small space at low cost

According to a fifth aspect of the present invention, in the first aspect of the invention, the current consumption of the object to be inspected is:
Since the configuration is such that the current value obtained by the current detection means of the slave power supply circuit is multiplied by the number of circuits of the slave power supply circuit, the current consumption of the DUT to be measured can be easily obtained. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a power supply device according to the present invention.

FIG. 2 is a schematic diagram of a power supply device according to the present invention.

FIG. 3 is a diagram illustrating a configuration of a power supply device according to the present invention.

FIG. 4 is a configuration diagram illustrating an example of a conventional power supply device.

FIG. 5 is a configuration diagram showing another example of a conventional power supply device.

[Explanation of symbols]

OP1, OP3 Control amplifier AMP1, AMP2 Boost amplifier OP2, OP4 Sense buffer amplifier R1, R2, R3, R4, R5, R6 Resistance U1, U2 Current detection means SW1, SW2, SW11, SW12, SW13, SW
14, SW15, SW16 switch

Claims (5)

[Claims] 1. A power supply device for use in a semiconductor integrated circuit test device or the like, wherein a power supply circuit for driving a plurality of power supply circuits in parallel to secure a current capacity required by a circuit under test indicates an output voltage. A signal input terminal to which a signal to be input is input, a control amplifier for amplifying a voltage signal input from the input terminal, a boost amplifier for current and voltage amplification of an output signal of the control amplifier, and a boost amplifier Current detection means for detecting an output current, feedback means for feeding back the output voltage of the boost amplifier to the input terminal of the control amplifier, and control signal output means for providing the output signal of the control amplifier to another power supply circuit A control signal input means for inputting a control signal of another power supply circuit to the boost amplifier, and outputting a control signal of a control amplifier of one master power supply circuit to a plurality of threads. Enter the boost amplifier of the probe power supply circuit, a power supply circuit for parallel driving, characterized in that it is configured to parallel driving a plurality of power supply circuits. 2. The power supply circuit according to claim 1, further comprising a control signal output unit and a control signal input unit. The power supply circuit having the same configuration can be used as a master power supply circuit or a slave power supply circuit. The power supply circuit according to claim 1, wherein: 3. The power supply circuit according to claim 1, wherein the slave power supply circuit is configured such that the number of parallel connections can be freely changed according to a current capacity required by a device to be inspected. 4. The power supply circuit according to claim 1, wherein said control signal output means and control signal input means are formed using a semiconductor switch circuit. 5. The power consumption of the test object is obtained by multiplying a current value obtained by current detection means of the power supply circuit by the number of power supply circuits driven in parallel. The power supply circuit according to claim 1.