KR100448857B1 - Apparatus for measuring supply current and current consumption of internal voltage generator, especially including transfer unit, external measurement unit, integrated pad and switching unit - Google Patents

Abstract

PURPOSE: An apparatus for measuring a supply current and current consumption of an internal voltage generator is provided to improve efficiency of circuit design. CONSTITUTION: According to a semiconductor memory device including a high voltage generator(10) generating a high voltage and a substrate bias voltage generator(20) generating a negative voltage, the first and the second transfer unit(MT1,MT2) transfer output voltages of the high voltage generator and the substrate bias voltage generator. An external current measurement unit(30) measures a supply current and current consumption of the high voltage generator and the substrate bias voltage generator by varying a voltage and a current applied to a memory. An integrated pad(40) is connected between the first and the second transfer unit and the external measurement unit, and provides the high voltage and the substrate bias voltage to the external measurement unit. And a switching unit(50) enables the first and the second transfer unit selectively.

Description

Supply and consumption current measuring device of internal voltage generator

The present invention relates to a device for measuring supply and power consumption of an internal voltage generator in various memory devices including a DRAM and a voltage generator. The present invention relates to an apparatus for measuring supply and consumption current of an internal voltage generator, which enables accurate measurement and supply current consumption of high voltage generators and substrate bias voltage generators, which are essential elements.

In general, in the memory test, not only the measurement of the total current consumption and the supply current, but also the specific parts, especially the important parts of the circuit, need to measure the various AC and DC currents of the circuit. The case is even more so.

In addition, since the information on the current consumed and supplied when the DRAM operates in various ways becomes a cornerstone of an efficient design, a large amount of current as well as a current consumption and a supply current flowing through the chip during the test or failure analysis are large. It is necessary to measure the exact consumption and supply current of the particular circuit flowing.

However, conventionally, when measuring the supply and consumption current of the chip, only the supply and consumption current of the entire chip was measured by measuring the amount of current consumption at the power supply voltage (Vdd) pad or the ground voltage (Vss) pad. The design specification only covered the total current consumption.

Therefore, in the conventional circuit design, it is impossible to predetermine the size of the circuit suitable for AC and DC characteristics, and it is difficult to diagnose the performance and abnormality of the system by adjusting the proper potential and current, and thus, there is a problem in that it is inferior in efficiency improvement. .

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to determine the performance and abnormality by measuring the supply and current consumption of the internal voltage generator to improve the efficiency of the circuit in the design of the internal voltage generator. To provide a supply and current consumption measuring device.

1 is a block diagram illustrating a semiconductor memory device including an internal voltage generator supply and consumption current measurement device according to an exemplary embodiment of the present invention.

FIG. 2 is a graph of variation of high voltage / substrate bias voltage according to the current change of FIG. 1.

3 is a graph showing a change in current consumption according to the high voltage / substrate bias voltage of FIG.

<Description of the symbols for the main parts of the drawings>

10: high voltage generator 20: substrate bias voltage generator

30: external meter 40: integrated pad

50: switch

In order to achieve the above object, the internal voltage generator supply and current consumption measuring apparatus according to the present invention is applied to the first and second transfer means for selectively transferring the output voltage of the high voltage generator and the substrate bias voltage generator, and applied into the memory External measurement means for measuring supply and consumption current of the high voltage generator and the substrate bias voltage generator by varying the amount of voltage and current to be supplied, and connected between the first and second transfer means and the external measurement means to obtain a high voltage and substrate bias voltage. And an integrated pad providing the external measuring means to the external measuring means, and switching means for selectively activating the first and second transmitting means.

The above and other objects and features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a semiconductor memory device including an internal voltage generator supplying and consuming current measuring device according to the present invention. First, a portion including and not including a high voltage generator 10 and a substrate bias voltage generator 20 is shown. The DRAM portion includes the transfer transistors MT1 and MT2 connected to the high voltage generator 10 and the substrate bias voltage generator 20 and the transfer transistors MT1 and MT2, respectively. And a high voltage-substrate bias voltage integrated pad 40 connected to an external meter 30 so as to simultaneously measure the substrate bias voltage Vbb and the currents Ipp and Ibb, and the two transfer transistors MT1 and MT2. And switch 50 to selectively activate each to deliver high voltage (Vpp) and substrate bias voltage (Vbb) to the high voltage-substrate bias voltage integrated pad 40. It is.

Hereinafter, the operation of the present invention having the above configuration will be described with reference to the drawings.

First, the overall outline will be described. A DRAM including the high voltage generator 10 and the substrate bias voltage generator 20 receives a current and a voltage from an external power supply voltage Vcc, and a part of the high voltage Vpp is internally. ) And the substrate bias voltage (Vbb), and related currents, and the rest are used elsewhere inside the DRAM.

At this time, after generating the high voltage (Vpp) and the substrate bias voltage (Vbb) in the high voltage generator 10 and the substrate bias voltage generator 20, a current that can escape to the outside through the high voltage-substrate bias voltage integrated pad 40 When referred to as Ipp and Ibb, respectively, in the conventional test, the external meter 30 only measures the current between the power supply potential (Vcc) and the ground potential (Vss), but in the present invention, the high voltage-substrate bias voltage integrated pad 40 By using), a current path can be created to measure the Ipp and Ibb and related currents.

Next, a detailed operation will be described with reference to FIG. 1.

In the first case, a method of measuring the pumping current of the high voltage generator 10 will be described. The power supply is applied to the DRAM to test the current and the high voltage-substrate bias voltage integrated pad 40 inside the DRAM is applied. Is connected to an external measuring device 30 capable of measuring current and voltage at the same time, and then the switch 50 is left in a low state, the first transfer transistor MT1 is turned on and the second transfer transistor MT2 is turned on. Is turned off to transfer the potential and current of the high voltage generator 10 to the high voltage-substrate bias voltage integrated pad 40.

In this state, when the current is applied to the high voltage-substrate bias voltage integrated pad 40 by forcing the current to flow backward, the change of the voltage can be measured. There will be time. That is, when the current is forcibly extracted to the maximum voltage that can be supplied from the high voltage generator 10, the potential is no longer maintained and falls. Therefore, measuring the current at this time will reveal the maximum current that can be produced by the high voltage generator.

FIG. 2 is a graph showing the change of the high voltage Vpp / substrate bias voltage Vbb according to the current change of FIG. 1, and the point A represents the maximum current value that each voltage generator can produce.

Of course, if the high voltage generator 10 has two types of stand-by mode and active mode, each supply current may be known by performing the above process with the DRAMs in two states.

In addition, the current consumption by measuring the current flowing through the integrated pad 40 after forcibly applying a voltage to the high voltage-substrate bias voltage integrated pad 40 from the external meter 30 as a method of measuring the current consumption (Ipp). It can be seen. In more detail, the high voltage generator 10 is generally divided into a sensing portion for detecting a high voltage (Vpp) and a pump portion for supplying a current to apply a potential, and the high voltage generator detects a high potential and turns on the pump. Determine whether to turn off. If forcibly applying a potential higher than the high voltage (Vpp) generated inside the DRAM to the high voltage-substrate bias voltage integrated pad 40 from the external measuring device 30, the sensing unit detects this and stops the operation of the pump. .

In this state, the current flowing into the DRAM through the integrated pad 40 through the external measuring device 30 becomes the high current consumption current Ipp. This current consumption includes the current that is essential for the normal operation of the DRAM and the leakage current due to process reasons, design failures or unavoidable circumstances.

If the voltage applied to the high voltage-substrate bias voltage integrated pad 40 is lower than the internally generated potential, current will flow to the external meter 30, and the potential applied to the integrated pad 40 will be equal to the internal high voltage. In almost the same case, the sum of the current flowing out of the external measuring device 30 and the current consumption in the DRAM becomes the current supplied by the pump to maintain the high voltage potential level at the internal high voltage level. Therefore, the sum of the current consumed and the current flowing out can determine the supply current of the pump.

FIG. 3 is a graph showing a change in current consumption (Ipp / Ibb) according to the high voltage (Vpp) / substrate bias voltage (Vbb) of FIG. 1, where point B is the supply current minus the consumption current, and point C is consumed. Indicates current.

When the supply current and the consumption current of the substrate bias voltage generator 20 are to be measured in the same manner as described above, the switch 50 for controlling the high voltage substrate bias voltage integrated pad 40 is placed in a 'high' state. In this case, the pad becomes a pad for measuring the substrate bias voltage and current, and in this state, the supply current and the consumption current of the substrate bias voltage generator can be measured as in the high voltage generator.

As described above, according to the apparatus for measuring supply and consumption current of the internal voltage generator according to the present invention, in addition to measuring the current consumption of the entire chip that falls directly to ground through the DRAM internal circuit at the power supply voltage, By measuring the current consumed by the high voltage generator and the substrate barius voltage generator and the current that can be supplied from the internal voltage generator, the size of the circuit can be pre-determined according to the DC and AC characteristics at the time of design. There is a very good effect that can be improved.

In addition, it is possible to design by removing unnecessary elements on the circuit in advance by accurate and efficient measurement, there is also an economic effect that can reduce the design cost.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the scope of the claims You will have to look.

Claims (2)

A semiconductor memory device comprising a high voltage generator for generating a high voltage and a substrate bias voltage generator for generating a predetermined negative voltage from a power supply voltage. First and second transfer means for selectively transferring output voltages of the high voltage generator and the substrate bias voltage generator; External measuring means for measuring supply and consumption currents of the high voltage generator and the substrate bias voltage generator by varying the amount of voltage and current applied into the memory; An integrated pad connected between the first and second transfer means and an external measuring means to provide a high voltage and a substrate bias voltage to the external measuring means; And a switching means for selectively activating the first and second transfer means. The method of claim 1, The first and second transfer means is a supply transistor of the internal voltage generator, characterized in that consisting of a transfer transistor.

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