JPH0336748A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To decide whether or not an internal circuit is satisfactory by measuring a current supplied only to the internal circuit without supplying the current to an external power supply line and without losing the function of an internal short-circuitting line by providing a switching element controlled so as to separate the external power supply line and an internal power supply line when the current to be injected into the internal circuit is measured. CONSTITUTION:When a current flowing into an internal circuit 22 is measured, a power supply is first supplied only to a power supply pad PAD 2, Thereupon, the power supply pad PAD 2 and an internal power supply line L2 are connected with each other through a diode D1. Further, a control line LC becomes a 'H' level and switching elements P1, P2 are made 'OFF', whereby an external power line L1 and the internal power supply line L2 are separated from each other. A current supply path from the power supply pad 2 to the external power supply circuit 23 is interrupted by the switching elements P1 and P2. Accordingly, only currents 11+12 flowing into the internal circuit 22 are indicated on an ammeter 25. From the result of current measurement, the internal circuit 22 can be decided on whether it is satisfactory or not.

Description

[Detailed Description of the Invention] [Summary] Semiconductor integrated circuit device, especially external ii related to external peripheral circuit
Regarding the power supply test of a device in which the R line and the internal power line related to the internal circuit are short-circuited, the current that is supplied only to the internal circuit without being supplied to the external power line and without impairing the function of the internal short-circuit line. The purpose of this test is to measure the external 'r!' connected to the power supply terminal to determine the quality of the internal circuit. 1. A semiconductor integrated circuit device comprising an internal power source line connected to an internal circuit and a switching element provided between the external power source line and the internal power source line, the switching element connected to the internal circuit. When measuring the inflowing current, the external power line and the internal power line are controlled to be separated, and m
There is.

[Field of Industrial Application] The present invention relates to a semiconductor integrated circuit device, and more specifically, the present invention relates to a power supply for a device in which an external power line related to an external peripheral circuit and an internal power line related to an internal circuit are short-circuited. It's about the exam.

In recent years, semiconductor integrated circuits have been developed that use bipolar transistors with high drive characteristics in external peripheral circuits and CMOS transistors with low power consumption characteristics in internal circuits.

According to this, when testing the operational function of the device, the external peripheral circuit and the internal circuit are separated, and the current supplied to the internal circuit can be measured. There is a need for a device that can connect

[Conventional technology]

FIG. 5.6 is an explanatory diagram of a conventional example.

FIG. 5 shows a configuration diagram of a conventional semiconductor integrated circuit device.

In the figure, the semiconductor integrated circuit device has an internal circuit 2 that incorporates various logic circuits mainly consisting of CuO2) transistors in a semiconductor chip 1, and a human output buffer (I10 board), etc., built in to take advantage of its high drive characteristics. External peripheral circuit 3
, an internal power supply line L2 serving as a power supply main line for the internal circuit 2, an external power supply line Ll serving as a power supply main line for the external circuit 3, and a plurality of power supply pads 1a to 1e connected to the external power supply line Ll and the internal power supply line L2. and an internal/external short-circuit line 4 that short-circuits the source line L1 and the external power line L2.

The internal/external shorting wire 4 connects the power supply pads 1a to 1e and the internal circuit 2.
This is provided to compensate for the voltage drop between the two and to draw current in a short period of time.

[Problem to be solved by the invention]

FIG. 6 is a test circuit diagram illustrating the problems of the conventional example.

In the figure, measurement of the power supply current related to the operational function test of the semiconductor integrated circuit device 10 is performed by simultaneously applying voltage to the power supply pads 1a to IC using a test device 5 such as a probing device for semiconductor testing. .

Therefore, the current flowing into the semiconductor integrated circuit device 10 through the power supply pads 1a to 1c, that is, the indication of the ammeter 6, is
Current 11 supplied to external peripheral circuit 3 etc. via line Ll
+13 and internal power line L2 connected to power band 1b
The total sum 11 + with I2 supplied to the internal circuit 2 via
It becomes T 2 +T 3. As a result, the external peripheral circuit 3
It is not possible to distinguish between the current 11+13 flowing into the internal peripheral circuit 5 and the t current 12 flowing into the internal peripheral circuit 5. If the current supply to the power supply pads la and lc is stopped, and the current supply to the power supply pad 1b is
Even if a current is supplied only to the external power supply line 4, the current flows into the external power supply line Ll through the internal/external shorting line 4, and the sum of the previously supplied currents, 11 + [2+ r 3, will flow.

As a result, it is not possible to measure the supply current of only the internal circuit 2 which is mainly incorporated with the CuO2) transistor, resulting in a problem that the quality determination of the semiconductor integrated circuit device becomes inaccurate.

The present invention was created in view of such conventional problems, and measures the current supplied only to the internal circuit without supplying it to the external power line and without impairing the function of the internal shorting line, and An object of the present invention is to provide a semiconductor integrated circuit that makes it possible to determine the quality of an internal circuit.

[Means for Solving the Problems] FIG. 1 shows a principle diagram of a semiconductor integrated circuit device of the present invention.

The device has an external power line Ll connected to the power supply terminal.
and an internal power supply line L2 connected to an internal circuit 12, a switching element 14 is provided between the external power supply line Ll and the internal power supply line L2, and the switching element 14 includes: When measuring the current flowing into the internal circuit 12, use the external power supply &? The above object is achieved by controlling so that tL1 and internal power supply line L2 are separated.

(Function) According to the present invention, the switching element 14 is provided which is controlled to separate the external power line Ll and the internal power line L2 when measuring the current injected into the internal circuit.

Therefore, in the principle diagram of FIG. 1, the switching element 1 provided between the external i source line LL and the internal power source line L2
By turning on 31 of 4, both internal and external power supply lines LL,
By short-circuiting L2, it is possible to have the effect of an internal/external short-circuit line as in the conventional example. In addition, S1 of the switching element 14 is first turned FF, and S2 of the switching element 14 is
By turning on the switching element 14, then selecting the power supply terminal 11 connected to the switching element 14 and applying power, it becomes possible to measure only the current supplied to the internal circuit 12.

As a result, it is possible to determine whether the internal circuit 12 is good or bad, so that it is possible to perform a more accurate functional operation test of the semiconductor integrated circuit device than in the conventional example.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2.3 explains a semiconductor integrated circuit device according to an embodiment of the present invention.

(i) Description of First Embodiment FIG. 2 shows a configuration diagram of a semiconductor integrated circuit device according to a first embodiment of the present invention.

In the figure, 20 is a semiconductor chip, which incorporates a semiconductor integrated circuit. 21 is a power supply pad (hereinafter referred to as PAD1 to PAD2) which is an example of the power supply terminal 11, and is a part to which a power supply voltage is applied. Reference numeral 22 denotes an internal circuit, which includes various logic circuits mainly composed of CMOS transistors. By using this CMOS transistor as the main component, it is possible to reduce the power consumption of the semiconductor integrated circuit device. Internal circuit 22 is connected to internal power supply line L2.

Reference numeral 23 denotes an external peripheral circuit, such as an input/output buffer (1/○ port) circuit mainly composed of bipolar transistors. Bipolar transistors have a larger current amplification factor hre than CMO3) transistors, and their driving power is also higher. Therefore, the amount of current flowing into the external peripheral circuit 23 is larger than that in the internal circuit 22.

Note that the external peripheral circuit 23 is connected to the external 1f source line L1. In the embodiment of the present invention, the external power line Ll is connected to power pads PAD1 and PAD3.

31 to S5 are examples of the switching elements 14, and switching elements Sl, S2 . There are two types: S4, S5, and switching element S3 connected between power supply pad PAD2 and internal power supply line L2. All switching elements S1 to S5 are connected to a control line LC, and the control is performed by selecting power supply pads PAD1 to PAD3.
For example, this is performed by supplying power to the power supply pad PAD2. These two types of switching elements Sl, S2. S4. The functions of S5 and S3 will be explained with reference to FIG.

FIG. 3 is an explanatory diagram of the switching element according to the first embodiment of the present invention, and shows a test circuit for measuring the 'Ei current flowing into the internal circuit 22.

In the figure, Pi and P2 are switching elements 31.3
2,34. This is a switching transistor element that is an example of S5, and in the example of the present invention, a P-type MO3) transistor is used. P type MO5) transistor Pi, P
The source of No. 2 is connected to the external power supply line Ll, and the drain thereof is connected to the internal power supply line L2. Further, their gates are connected by a control line C and connected to a power supply pad PAD2. In addition, the control LC includes a pull-down resistor R.
1 is connected.

DI is a discrimination element which is an embodiment of the switching element S3, and a diode is used in the embodiment of the present invention. The anode of the diode is connected to the power band PAD2, and the cathode is connected to the internal power line.

Further, 24 is a test device, such as a blowing device for semiconductor testing. 25 is an ammeter that detects the current flowing through the blobbing needle.

Therefore, for example, when the power supply is a positive 11it source and the current flowing into the internal circuit 22 is to be measured, first, power is supplied only to the power supply pad PAD2. At this time, the diode DI connects the power supply pad PAD2 and the internal power supply line L.
2 is connected. Further, since the control line LC becomes "H" level and the switching elements PI and P2 perform "FFJ", the external power supply line Ll and the internal power supply line L2 are separated.

A current supply path from power supply pad PAD2 to external power supply circuit 23 is cut off by switching elements PL and P2. From this, only the current 11+12 flowing into the internal circuit 22 is indicated to the ammeter 25. Based on the current measurement result, it is possible to determine whether the internal circuit 22 is good or bad.

Note that, except during testing, power is applied to the source pads PAD1 and PAD3. In addition, 1. Since no voltage is applied to the power supply pad PAD2, the control line LC becomes "L" level, and the switching element PIP2 becomes "ON", thereby short-circuiting the external 1i source line L1 and the internal power supply line L2. It can be operated normally together with internal circuits and external peripheral circuits.

(ii) Description of Second Embodiment FIG. 4 is an explanatory diagram of a switching element according to a second embodiment of the present invention.

In the figure, the difference from the first embodiment is that the second embodiment has switching elements Sl, S2 . N-type MOS) transistors are used for S4 and N5, and a protection diode D2 and an N-type MOS) transistor are used for the switching element S3.

The other components are the same as those in the first embodiment, so their explanation will be omitted.

That is, switching elements Sl, S2 . S4. N-type MOS transistors (switching elements) Nl and N3, which are an embodiment of N5, have their sources and gates short-circuited and connected to an external power supply line Ll.

Diode D2 which is an example of switching element S3
and N-type MOS) transistor (switching element) N2, the anode of diode D2 is connected to power supply pad PAD2, the cathode is connected to the point where the source and gate of N-type MOS) transistor N2 are short-circuited, and its drain is the internal power supply! It is connected to 1tL2.

Therefore, as in the first embodiment, when the power supply is a positive power supply and the current flowing into the internal circuit 22 is to be measured, first, power is supplied only to the power supply pad PAD2. At this time, the diode D2. Switching element N2 connects power supply pad PAD2 and internal power supply line L2. In addition, other switching elements Nl, N3, rOFFJ
1. , the internal power supply line L1 and the external power supply line are separated.

Therefore, the current supply path from the power supply pad PAD2 to the external IT source circuit 23 is cut off by the switching element. Therefore, only the current flowing into the internal circuit 22 can be measured. Based on this measurement result, the quality of the internal circuit 22 can be determined as in the first embodiment.

In addition, except for the test, by supplying power to all power pads PADI to PAD3, the switching element Nl
, N3 are turned "ON", thereby providing the effect of the internal/external shorting line 4 as in the conventional example.

Thus, according to each embodiment of the invention, the switching elements Pi, P2 . Nl~N3 and diode DI
, D2 are provided.

Therefore, the switching elements PL, P2, Nl, N provided between the external power supply line Ll and the internal source line L2 are
By turning ON 3, both the internal and external power supply lines Ll and L2 are short-circuited, and the effect of the internal-external short circuit 144 as in the conventional example can be produced. In addition, switching elements PI, P
2, Nl, and N3 are first turned off, and the discrimination elements Di and D2 and the switching element N3 are turned on. Next, by applying power to the power supply pad PAD2 connected to the discrimination elements DI and D2, it becomes possible to measure only the current supplied to the internal circuit 22.

As a result, it is possible to determine whether the internal circuit 22 is good or bad, so that it is possible to perform a more accurate functional operation test of the semiconductor integrated circuit device than in the conventional example.

In each embodiment of the present invention, the case of positive taI has been described, but also in the case of negative power supply, only the current supplied to the internal circuit can be measured as in the case of positive power supply.

C. Effects of the Invention] As described above, according to the present invention, by selecting a power supply pad using a switching element, it is possible to distinguish between the currents flowing into the external power supply line and the internal power supply line.

Therefore, since current can flow only into the internal power supply line, it becomes possible to measure only the current supplied to the internal circuit during testing, and to connect the internal and external power supply lines except during testing.

This makes it possible to accurately perform operational function tests of internal logic circuits, etc., which greatly contributes to the manufacture of highly reliable semiconductor integrated circuit devices.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of a semiconductor integrated circuit device according to the present invention. FIG. 2 is a diagram of a semiconductor integrated circuit device according to a first embodiment of the present invention. FIG. 4 is an explanatory diagram of a switching element according to a second embodiment of the present invention; FIG. 5 is an explanatory diagram of a switching element according to a second embodiment of the present invention; FIG. FIG. 6 is a test circuit diagram illustrating problems with the conventional example. [Explanation of symbols] 11... power supply terminal, 12... internal circuit, 13... external peripheral circuit, 14... switching element, Ll... external power line, L2... internal power supply line.

Claims (1)

[Claims] A semiconductor integrated circuit device comprising an external power line (L1) connected to a power supply terminal and an internal power line (L2) connected to an internal circuit (12), wherein the external power line (L1)
A switching element (14
), and the switching element (14) controls to separate the external power line (L1) and the internal power line (L2) when measuring the current flowing into the internal circuit (12). Features of semiconductor integrated circuit devices.