JP2006047175A - Current measuring method, current measuring program, measuring device and electronic computer running above program, manufacturing apparatus equipped with them, and semiconductor integrated circuit and electronic equipment equipped with means carrying out above current measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out a current measurement precisely for a short time, by rapidly reducing and completing charging of current on a parasitic capacitance or the like, which flows into an element in a circuit block just after applying a supply voltage for the current measurement to the circuit block whose circuit function is turned off. <P>SOLUTION: In a circuit of a plurality of circuit blocks being always supplied with the supply voltage from one power source shared by them, when subjecting only a circuit block 1 to the current measurement in such a condition of the circuit block 1 whose circuit function is turned on, and a circuit block 2 whose circuit function is turned off, the current of the circuit block 1 becomes stable and reaches its steady state immediately after its start caused by applying the supply voltage. In the case of the current of circuit block 2, current (curve C) of a power supply terminal requires a period to arrive at a position (g) equivalent to current (curve A) of only the circuit block 1, during a transition period of time when its inner circuit comes into an appropriate off state just after the applying. The circuit block 2 is turned on (position (i)) to make a state in which the current flows after the application of the supply voltage, and is turned off (position (j)) after a certain elapse of time, thereby shortening the period up to a position (k) where the current such as parasitic charging current or the like of the circuit block 2 is nearly zero as shown by a curve D. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a current measuring method, a current measuring program, a measuring instrument for executing the current measuring method, an electronic computer, and a manufacturing apparatus including these, for measuring a weak current of an electronic device such as an electronic circuit including a semiconductor integrated circuit in an extremely short time. The present invention relates to a semiconductor integrated circuit and an electronic device having means for executing a current measuring method.

As a conventional method for measuring a circuit current, a circuit current measuring method is used in which a state in which a current flowing in a circuit is stabilized is monitored and measurement is performed after confirming that the current is stable. (For example, refer to Patent Document 1).
JP 2000-227448 A

  Problems in the prior art will be described with reference to FIGS.

  In recent electronic devices and component circuits, the power is always supplied, but the circuit is stopped when it is not necessary, and the circuits other than those necessary are stopped to reduce power consumption and standby power. In many cases, measures are taken to extend the time during which the battery can be driven by reducing power consumption or standby power.

  For example, in mobile terminals such as mobile phone systems and large-scale integrated circuits, each function in the system is divided into on and off, or in large-scale integrated circuits, grouped circuit blocks are turned on under various conditions. In many cases, the current consumption is measured separately for the off-block, and the number of inspections increases accordingly.In addition, the current consumption of the circuit that is turned on in the standby state is very small, so the measurement current is switched off. As the absolute value of the sum of the parasitic charge currents of the circuit blocks that are close to each other approaches, it takes a long time to accurately measure the weak current of the circuit that is turned on. The time is getting longer and the overall inspection time is getting much longer.

  In addition, when all the circuits in standby are stopped, the power supply current or a minute current that some circuits are operating and other circuits are stopped should also be measured and disclosed as a performance judgment index. Has increased.

  For example, in a system (circuit) in which there are two circuit blocks whose circuit functions can be individually turned on / off as shown in FIG. 5, the power supply current is measured when the circuit block 1 is turned on and the circuit block 2 is turned off. When the power supply voltage for current measurement is supplied in the control state in which the control of the circuit block 1 is turned on and the control of the circuit block 2 is turned off by the control signal, as shown in FIG. The current of the circuit block 1 is slightly disturbed when the power supply voltage for current measurement is applied as shown by curve A, but rises relatively smoothly, rises to the design value, and stabilizes.

  However, the power supply current of the circuit block 2 that has been controlled to be turned off from the beginning is a variety of bias currents, as shown by curve B, immediately after application of the power supply voltage for current measurement until the circuit is fixed in the off state. Flows. Since this current accounts for a proportion of the initial parasitic charging current to the parasitic capacitance of the wiring or circuit element, the current flows for a while until the charging is completed. For this reason, when measuring the entire accurate power supply current, the curve C, which is the combined current of the curve A and the curve B, is measured, and the position where the parasitic charging current is almost eliminated, the position (g) shown in FIG. I need to wait.

  Next, the power supply current will be described below with reference to the circuit example of the current measurement target shown in FIG. In FIG. 4, a bias from a bandgap reference current source is supplied to the gate of MOSFET Q1, and MOSFETs Q3 and Q4 are sequentially operated to supply current to the differential circuit. When this circuit is turned off, the bias supply path from the band gap to the MOSFET Q1 is cut off, and the MOSFET Q2 is turned on to stop the operation of the MOSFET Q3 as a mirror circuit.

  However, at the moment when the power supply voltage (VCC) for current measurement is supplied with the circuit turned off, it is supplied to the sources of the MOSFETs Q1, Q5, Q6, and Q8. Furthermore, at least Vgs of the MOSFET Q5 is generated and a drain current is generated. The drain current of the MOSFET Q5 is eventually reduced as the potential A is increased, but Vgs of the MOSFET Q6 is also generated in parallel. Rises, the MOSFET Q8 is turned on, and even if all the loads connected to the source of the MOSFET Q8 are turned off, the drain current of the MOSFET Q8 flows as a slight charging current, and then decreases.

  When the circuit is on, the drain currents of the MOSFETs Q3, Q4, and Q7 are determined by the band gap reference current, and there is a similar parasitic charging current at the moment of VCC supply, but its absolute value is the drive when the circuit is on. Since it is smaller than the current (drain currents of the MOSFETs Q3, Q4, and Q7) and the circuit is conductive, the charging to the parasitic capacitance is completed quickly, so that the time influence on the current measurement is extremely small.

  As described above, in order to obtain an accurate current measurement value in the conventional measurement method, it is necessary to wait until the charging current of the parasitic capacitance disappears. Therefore, there is a problem that the time required for the measurement becomes long.

  The present invention is directed to solving the problems of the prior art, and the circuit function is turned off immediately after the power supply voltage for current measurement is applied to the circuit block whose circuit function is turned off. A current measurement method that quickly reduces or completes the charging current to the parasitic capacitance flowing into the elements in the block and measures the current accurately in a short time, and a current measurement program and a measuring instrument or electronic computer that executes the current measurement program Another object of the present invention is to provide a semiconductor integrated circuit or an electronic device provided with a measuring device that executes the current measuring method and a manufacturing apparatus including these.

  In order to achieve the above object, a current measuring method according to the present invention includes a circuit block that shares the same power supply, operates with power supply from the same power supply, and can perform on / off control of a circuit function, and a circuit function Current measurement for measuring the current of a specific circuit block alone or within a specific range in a circuit composed of a plurality of circuit blocks each having at least one circuit block that cannot be turned on / off. The first method is a circuit block in which on / off control of circuit functions other than the circuit block to be measured in the circuit can be performed, and the circuit function is turned on at least once to supply current to the elements in the circuit block. Is turned off before measuring the current of the circuit block to be measured, so that the charging current flowing into the capacitance components at every corner in the circuit block can be reduced. It is reduced, or by the to complete measuring the current of the circuit block, a state capable of measuring more quickly accurate current to reduce the time to measure things.

  In the second method, in the circuit block that can perform on / off control of the circuit functions other than the circuit block to be measured in the circuit, the current is measured before the current measurement with the circuit function turned off. By applying a high voltage to increase the charging current that flows into the capacitive components at every corner of the circuit block, and then returning the high voltage to the original power supply voltage, charging by the charging current is accelerated before measurement. By measuring the current of the circuit block after quickly reducing or completing the charging current, the time for measurement can be shortened, and a more accurate current can be measured more quickly.

  In addition, by using the first and second methods in combination, by measuring the current of a specific circuit block in a circuit or a plurality of circuit blocks within a specific range, the measurement time can be further shortened and more quickly It is possible to make it possible to measure an accurate current.

  In addition, the current measurement program, the measuring instrument that executes the program, the electronic computer, and the manufacturing apparatus equipped with them operate the measuring instrument based on the current measuring method and automatically measure the circuit current by electronic control. A current measurement program in which the operating procedure of the means to be described is described, which is incorporated in the measuring instrument or in an electronic computer used to control the measuring instrument and measures the current of the circuit according to the operating procedure In addition, a current measurement program is incorporated into the measuring instrument or electronic computer, and the current of the circuit is automatically measured by electronic control by executing the current measuring program. Further, the measuring instrument or electronic computer is installed in the manufacturing apparatus. Used as part of the configuration, by measuring the current flowing in the semiconductor integrated circuit or electronic equipment circuit to be manufactured, by electronic control Dynamically measuring the current of the circuit can be reduced efficiently manufacturing cost extremely reduced can semiconductor integrated circuit or electronic device the overall inspection time.

  Further, a semiconductor integrated circuit and an electronic apparatus provided with means for executing a current measuring method are provided with measuring means for measuring current based on the current measuring method, and the measuring means is directly incorporated inside and configured internally. With the configuration having a function of measuring and self-confirming the current of a part of or the entire circuit, the current can be measured more accurately in a short time in a semiconductor integrated circuit or an electronic device alone.

  According to the present invention, immediately after the power supply voltage for current measurement is applied to the circuit block whose circuit function is turned off, the charging current to the parasitic capacitance flowing into the elements in the circuit block is quickly reduced or completed. The current of the target circuit block can be measured with high accuracy in a short time, the total inspection time can be extremely shortened, and the manufacturing cost can be efficiently reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a current characteristic diagram for explaining a current measuring method according to the first embodiment of the present invention. The first embodiment will be described with reference to FIGS.

  In the circuit having a plurality of circuit blocks that share the same power supply and are always supplied with the power supply voltage from the same power supply, the circuit block 1 is turned on and the circuit block 2 is turned off. In the case of measuring only the power supply current, when the power supply voltage for current measurement is applied with the control signal of the circuit block 1 turned on and the control signal of the circuit block 2 turned off, the current of the circuit block 1 controlled to be on is Immediately after start-up, it reaches a steady state relatively stably and becomes a constant current. However, the current of the circuit block 2 which is controlled to be off is the current and circuit due to various transient responses in the transition period until the state of the internal circuit becomes an appropriate off state immediately after the power supply voltage for current measurement is applied. The charging current to the parasitic capacitance of the element or the element, the wiring, etc. flows for a while, and the current (curve C) flowing to the power supply terminal is equivalent to the current (curve A) of only the circuit block 1 controlled to be on. It takes time to reach the position (g) (see FIG. 1).

  However, after the power supply voltage for current measurement is applied, the circuit block 2 is once turned on (position (i)) so that a bias voltage is generated in the circuit in the circuit block 2 so that the bias current flows, and it is turned on for a certain period of time. Is turned off (position (j)). As a result, the time until the current such as the parasitic charging current of the circuit block 2 almost disappears as shown by the curve D is once turned on from the position (g) where the parasitic current almost disappears when the circuit block 2 is not turned on once. It is possible to smoothly shorten the position to the position (k) where the current such as the parasitic charging current almost disappears.

  As described above, when the current of a specific circuit block alone or a plurality of circuit blocks is measured in a specific range, in a circuit block capable of on / off control other than the circuit block to be measured in the circuit, the circuit is at least once. By turning on the function and then turning it off before measuring the current of the target circuit block to be measured, the time required for precise current measurement of the target circuit block can be greatly reduced. .

  The current measurement method according to the first embodiment can be applied to the case where all circuit blocks measure the current when the circuit block is off, or the case where the sleep current when the individual circuit block is off is measured. The present invention can also be applied to a case where a circuit block that cannot be turned off is included.

  Further, the timing and the period for turning on the circuit block to be turned off at the time of current measurement are arbitrary before the current measurement, and may be turned on simultaneously with application of the power supply voltage for current measurement. The on period may be determined by optimization or approximate.

  In addition, a plurality of existing circuit blocks are divided into several groups in advance, sequentially turned on at different times, turned off, and then turned on / off for other circuit blocks. Of course, several grouped circuit blocks may be turned on sequentially and turned off collectively, or after all of them are turned on at the same time, each circuit block may be turned off arbitrarily.

  FIG. 2 is a current characteristic diagram for explaining a current measurement method according to the second embodiment of the present invention. The second embodiment will be described with reference to FIGS.

  In the circuit having a plurality of circuit blocks that share the same power supply and are always supplied with the power supply voltage from the same power supply, the circuit block 1 is turned on and the circuit block 2 is turned off. In the case of measuring only the power supply current, when the power supply voltage for current measurement is applied with the control signal of the circuit block 1 turned on and the control signal of the circuit block 2 turned off, the current of the circuit block 1 controlled to be on is Immediately after start-up, it reaches a steady state relatively stably and becomes a constant current. However, the current of the circuit block 2 that is controlled to be off is the current and circuit due to various transient responses in the transition period until the state of the internal circuit becomes an appropriate off state immediately after the power supply voltage for current measurement is applied. The charging current to the parasitic capacitance of the element or the element, the wiring, etc. flows for a while, and the current (curve C) flowing to the power supply terminal is equivalent to the current (curve A) of only the circuit block 1 controlled to be on. It takes time to reach the position (g) (see FIG. 2).

  However, after or at the time of applying the power supply voltage for current measurement, a voltage higher than the power supply voltage applied during current measurement is applied while the circuit block 1 is turned on and the circuit block 2 is turned off. The charging current such as a parasitic current at the time of applying a voltage to the circuit block 2 controlled to be off is increased (increase period from the position (i ′) to the position (j ′) in FIG. 2) to some extent. When the measurement is performed, the high voltage is returned to the power supply voltage at the predetermined measurement (position (j ′)), and at the time of measurement, the current such as the parasitic charge current of the circuit block 2 by the power supply voltage of the current measurement. It is possible to improve the time (position (g)) at which current measurement is possible when waiting for almost disappears to the position (k ′) of the curve D ′.

  In this way, when measuring a current of a circuit block that is turned on by turning on a plurality of circuit blocks in a specific circuit block alone or a specific range of a circuit composed of a plurality of circuit blocks and turning off the other circuit blocks, For a certain period of time until the current is measured, the power supply voltage applied for measurement is set to a voltage higher than the power supply voltage at the time of actual current measurement, and the parasitic charge current to the circuit block being turned off is increased. Thus, the time required for precise current measurement of the target circuit block can be greatly shortened.

  Note that the current measurement method according to the second embodiment can be applied to the case where all circuit blocks measure the current when the circuit block is off or the sleep current when the single circuit block is off. The present invention can also be applied to a case where a circuit block that cannot be turned off is included.

  Further, the timing and period for increasing the power supply voltage during current measurement are arbitrary, and the voltage may be increased from the time of application of the power supply voltage for current measurement.

  In addition, the period during which the power supply voltage for current measurement is high may be determined or optimized by optimization. Furthermore, the voltage to be increased at that time is also arbitrary, and may be determined within a range where there is no problem in configuration and within a range where there is no problem in circuit operation.

  FIG. 3 is a current characteristic diagram for explaining a current measuring method according to the third embodiment of the present invention. The third embodiment will be described with reference to FIGS. 3 and 5.

  In the circuit having a plurality of circuit blocks that share the same power supply and are always supplied with the power supply voltage from the same power supply, the circuit block 1 is turned on and the circuit block 2 is turned off. In the case of measuring only the current, when the power supply voltage for current measurement is applied with the control signal of the circuit block 1 turned on and the control signal of the circuit block 2 turned off, the current of the circuit block 1 controlled to be turned on is activated. Immediately after, a steady state is reached and a constant current is reached. However, the current of the circuit block 2 which is controlled to be off is the current and circuit due to various transient responses in the transition period until the state of the internal circuit becomes an appropriate off state immediately after the power supply voltage for current measurement is applied. The charging current to the parasitic capacitance of the element or the element, the wiring, etc. flows for a while, and the current (curve C) flowing to the power supply terminal is equivalent to the current (curve A) of only the circuit block 1 controlled to be on. It takes time until the position (g).

  Even if the current measurement method described in the first embodiment is used, there is a case where a little charging current remains as shown between the positions (j)-(k) of the curve D shown in FIG. In order to further reduce the time required for this portion, the circuit block that is turned off at the time of current measurement before current measurement is turned on using the current measurement method described in the second embodiment as shown in FIG. Then, turn it off. At the same time, before and after that, by setting the power supply voltage for current measurement to a voltage higher than the voltage at the time of measurement, as shown in the position (n) of curve E in FIG. By applying a voltage higher than the power supply voltage for current measurement to increase it once, and then returning the high voltage to the voltage at the time of measurement before current measurement, the time until the parasitic charging current almost disappears is reduced to the position (k in FIG. ) To position (m).

  Thus, by using the measurement methods of the first and second embodiments in combination, the time required for precise current measurement of the target circuit block can be greatly shortened.

  Note that the current measurement method according to the third embodiment can be applied to the case where all circuit blocks measure the current when the circuit block is off or the sleep current when the single circuit block is off. The present invention can also be applied to a case where a circuit block that cannot be turned off is included.

  Further, the timing and the period for turning on the circuit block to be turned off at the time of current measurement are arbitrary as in the first embodiment described above, and in order to increase the charging current of the parasitic charging current at the off time, The timing and the period for making the applied voltage higher than the power supply voltage at the time of measurement are arbitrary as in the second embodiment. In addition, the circuit block that is turned off during current measurement may be turned on and then turned off, and then the power supply voltage for current measurement may be increased. The interval between them may be arbitrary, and these are all determined by optimization, etc. do it.

  Further, based on the current measurement method described in the first to third embodiments, this current is used as a current measurement program that describes the operation procedure of means for automatically measuring the circuit current by electronic control by operating the measuring instrument. The measurement program is built into the measuring instrument and the electronic computer used to control the measuring instrument, and by measuring the circuit current according to this operation procedure, the current measurement of the target circuit block is automatically controlled electronically. In addition, it is possible to obtain a measuring instrument or an electronic computer that can be accurately performed in a short time and can perform this current measurement.

  Furthermore, a current measuring device or electronic computer in which a current measuring program is incorporated is configured as a manufacturing apparatus that uses a part of the configuration, and the current flowing through the circuit of the semiconductor integrated circuit or electronic device to be manufactured is measured. Thus, the measurement time can be shortened and the measurement can be performed accurately, and the manufacturing cost of the semiconductor integrated circuit or the electronic device can be reduced.

  Further, the semiconductor integrated circuit or the electronic device is provided with a measuring unit for measuring current based on the current measuring method of the first to third embodiments, and the measuring unit is directly built in and configured internally. By having a function of measuring and partially confirming the current of a part of or the entire circuit, the current can be measured more accurately in a short time even in a semiconductor integrated circuit or an electronic device alone.

  A current measurement method, a current measurement program, a measuring instrument and an electronic computer that execute the current measuring method, a manufacturing apparatus including the current measuring method, a semiconductor integrated circuit and an electronic device including a unit that executes the current measuring method, have a circuit function. Immediately after applying the power supply voltage for current measurement to the circuit block that is turned off, the charging current to the parasitic capacitance that flows into the elements in this circuit block is quickly reduced or completed, and the current of the target circuit block is accurately As a means to improve inspection efficiency, it is possible to measure well in a short time, greatly reducing the total inspection time, and measuring weak currents in electronic devices such as electronic circuits including semiconductor integrated circuits in an extremely short time. Useful.

Current characteristic diagram for explaining a current measurement method in Embodiment 1 of the present invention Current characteristic diagram for explaining a current measurement method in Embodiment 2 of the present invention Current characteristic diagram for explaining a current measurement method in Embodiment 3 of the present invention The figure for demonstrating the example of a circuit of the conventional current measurement object Block diagram showing the circuit configuration consisting of multiple circuit blocks Current characteristics diagram explaining conventional current measurement method

Explanation of symbols

1, 2 circuit block

Claims (9)

At least one circuit block that shares the same power supply, operates with power supply from the same power supply, and that can perform on / off control of the circuit function, and at least one circuit block that cannot perform on / off control of the circuit function A current measurement method for measuring currents of a specific circuit block alone or within a specific range in a circuit composed of a plurality of circuit blocks,
In a circuit block capable of on / off control of circuit functions other than the circuit block to be measured in the circuit, the circuit function is turned on at least once to supply current to the elements in the circuit block, and then the circuit to be measured A current measuring method comprising: turning off the current before the block current is measured to quickly reduce or complete the charging current flowing into the capacitive components in the corners of the circuit block, and then measuring the current of the circuit block. . At least one circuit block that shares the same power supply, operates with power supply from the same power supply, and that can perform on / off control of the circuit function, and at least one circuit block that cannot perform on / off control of the circuit function A current measurement method for measuring currents of a specific circuit block alone or within a specific range in a circuit composed of a plurality of circuit blocks,
In a circuit block that can perform on / off control of circuit functions other than the circuit block to be measured in the circuit, a voltage higher than the power supply voltage for performing the current measurement is applied before the current measurement with the circuit function turned off. , Increasing the charging current flowing into the capacitance components in the corners of the circuit block, and then returning the high voltage to the original power supply voltage, thereby accelerating the charging by the charging current before the measurement, and the charging current A current measuring method comprising: measuring the current of the circuit block after quickly reducing or completing the current.   3. A current measuring method comprising: measuring a current of a specific circuit block in a circuit or a plurality of circuit blocks in a specific range by using the circuit current measuring method according to claim 1 or 2 together.   A current measurement program in which an operation procedure of means for automatically measuring a circuit current by electronic control is described by operating a measuring instrument based on the current measurement method according to any one of claims 1 to 3. A current measurement program for measuring the current of the circuit according to the operation procedure, incorporated in the measuring instrument or incorporated in an electronic computer used to control the measuring instrument.   A current measuring program according to claim 4, wherein the current of the circuit is automatically measured by electronic control by executing the current measuring program.   5. An electronic computer in which the current measurement program according to claim 4 is incorporated, and the current of the circuit is automatically measured by electronic control by controlling the measuring instrument by executing the current measurement program.   An apparatus for measuring a current flowing in a circuit of a semiconductor integrated circuit or an electronic device to be manufactured by using the measuring instrument according to claim 5 or the electronic computer according to claim 6 as a part of its configuration.   A measurement means for measuring current based on the current measurement method according to any one of claims 1 to 3, comprising a part of a circuit configured inside the measurement means by directly incorporating the measurement means therein A semiconductor integrated circuit characterized by having a function of measuring and self-identifying the entire current.   A measurement means for measuring current based on the current measurement method according to any one of claims 1 to 3, comprising a part of a circuit configured inside the measurement means by directly incorporating the measurement means therein An electronic device having a function of measuring the entire current and self-checking.

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