JP2000294728A - Semiconductor device - Google Patents

Abstract

(57) [Problem] To provide a semiconductor integrated circuit having a self-test function capable of shutting off power supply by itself even if a short circuit fault occurs in an internal circuit. SOLUTION: A protection circuit including a resistance element 7 is connected between an external power supply 2 and an internal circuit 4 of the semiconductor integrated circuit, and when a short circuit failure occurs in the internal circuit 4, the internal circuit 4 is cut off from the external power supply 2. At the same time, the transistors 5 and 6 serving as switching circuits are connected to the resistor 7 by-pass, and when a short circuit failure does not occur in the internal circuit 4, power is stably supplied from the bypass circuit to the internal circuit 4. When a short-circuit failure occurs, the power supply to the internal circuit 4 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device for avoiding a test or use defect caused by a short circuit of an internal circuit of a semiconductor device by a self-test function.

[0002]

2. Description of the Related Art FIG. 9 is a schematic diagram showing a conventional semiconductor device. A conventional semiconductor device 22 has an internal circuit 4 which is a semiconductor integrated circuit, and has a power supply terminal 19, a GND terminal 2
0 and a signal terminal 21 for external connection. The power supply device 2 supplies power when the semiconductor device 22 is operated or tested, and is connected to a power supply terminal 19 of the semiconductor device 22. On the other hand, G of the semiconductor device 22
The ND terminal 20 is connected to the ground 3. Here, when the conventional semiconductor device 22 is operated, the potential of the power supply device 2 is applied to the internal circuit 4 of the semiconductor device 22 via the power supply terminal 19.
, And the GND potential is supplied from the GND terminal 20 to the ground 3
Connected to.

FIG. 10 shows a conventional semiconductor device 22 having a plurality of semiconductor devices 22.
2a, b, c... Show a configuration diagram of, for example, a burn-in test for connecting and testing in parallel. In the figure, the resistor 23
(23a, b, c...) Indicate the respective semiconductor devices 22a, b, c.
Are connected in series between the power supply terminal 19 of the... And the power supply 2 built in the burn-in device (not shown),
When a short-circuit fault occurs in the internal circuit 4, the current flowing through the semiconductor device 22 serves to disconnect. That is, the defective conventional semiconductor device 2
2 is separated from the power supply device 2 so that another conventional semiconductor device 22 can continue the burn-in test.

FIG. 11 is a configuration diagram in which a conventional semiconductor device 22 is arranged on a burn-in board. On a single burn-in board 24, a plurality of semiconductor devices 22 have the power supply wiring 8 from the power supply device 2 and the GND potential. G connected to grounding part 3
It was mounted in parallel with the ND wiring 9. A resistor 23 is connected in series to the power supply terminal 19 of each semiconductor device 22 as shown in FIG. conventionally,
Each time the type of the semiconductor device 22 is different, the resistor 23 must be replaced, and a plurality of types of burn-in boards 24 must be prepared for each type of the semiconductor device 22.
Also, if there is a resistor 23 that has been disconnected due to a defective semiconductor device 22, the burn-in board 24 must be tested and replaced before the burn-in test.

FIG. 12 is a configuration diagram showing a conventional system using a large number of semiconductor devices 22. As shown in FIG. In the figure, a plurality of semiconductor devices 22 are mounted on a mounting board 26 of a system, and a protection circuit (for example, a fuse) 25 is provided to protect the entire system. That is, in the system using the conventional semiconductor device 22, the protection circuit 25 is inserted between the power supply device 2 and the system mounting board 26 in order to prevent the system from being destroyed due to the failure of the semiconductor device 22. However, here, in many cases, only one protection circuit 25 is provided for the entire system. Therefore, the threshold value cut off by the protection circuit 25 is set to a large value such as the total operating current of the semiconductor device 22 of the entire system. However, there is a problem that the mounting board 26 of the system is broken due to an overcurrent.

[0006]

As described above, in the burn-in test of the conventional semiconductor device, the resistor must be replaced every time the type of the semiconductor device is different.
A plurality of types of burn-in boards must be prepared for each type of semiconductor device, and furthermore, a resistor disconnected by a defective semiconductor device must be tested and replaced for each burn-in test.

Further, in a system using a conventional semiconductor device, it is costly to provide a protection circuit for preventing the destruction of the system for each semiconductor device, so that only one protection circuit is provided in the entire system. In many cases, the threshold value to be cut off by the protection circuit must be set to a large value such as the sum of the operating currents of the semiconductor devices in the entire system, and there is a problem that an overcurrent destroys a system mounting board. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to cut off the power supply by itself even if a short circuit occurs in an internal circuit. Provided is a semiconductor device having a self-test function capable of continuously performing a burn-in test on a normal semiconductor device and protecting the system without providing a protection circuit in the system.

[0009]

According to a first aspect of the present invention, there is provided a semiconductor device connected between an external power supply and an internal circuit of the semiconductor device, and when a short circuit fault occurs in the internal circuit, the internal circuit is connected to the external power supply. A protection circuit for disconnecting from the protection circuit, and a bypass connected to the protection circuit, when the short circuit failure does not occur in the internal circuit, the power is stably supplied to the internal circuit, and when the short circuit failure occurs in the internal circuit, A switching circuit for stopping power supply to the internal circuit is built in.

According to a second aspect of the present invention, as the protection circuit,
The semiconductor device is characterized by comprising a resistance element that is disconnected when a short circuit failure occurs in the internal circuit.

According to a third aspect of the present invention, as the protection circuit,
It is characterized by including a transistor that breaks down when a short circuit failure occurs in the internal circuit.

According to a fourth aspect of the present invention, as the protection circuit,
It is a combination circuit of a complementary transistor and a complementary transistor having an inversion function, which conducts when a short circuit failure does not occur in the internal circuit and becomes non-conductive when a short circuit failure occurs. And

According to a fifth aspect of the present invention, the switching circuit is turned on when a short circuit does not occur in the internal circuit, and is turned on when a short circuit occurs in the internal circuit.
It is characterized by including a transistor for flip-flop.

According to a sixth aspect of the present invention, a p-type transistor is used as a transistor of the switching circuit, and when a short circuit fault does not occur in the internal circuit, the transistor is turned on, and a short circuit fault occurs in the internal circuit. And an inversion circuit that turns off the power supply when the power supply is turned off.

According to a seventh aspect of the present invention, a plurality of transistors of the switching circuit are provided in parallel so as to bypass the protection circuit.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a semiconductor device according to Embodiment 1 of the present invention. As shown in the figure, in the semiconductor device 1 according to the first embodiment, a resistance element 7 is connected between an internal circuit 4 which is a semiconductor integrated circuit and an external power supply device 2. The resistance element 7 serves as a protection circuit for disconnection due to a current generated due to a short-circuit failure of the internal circuit 4 and is formed by a wafer process when the semiconductor device 1 is manufactured.

When power is supplied from the power supply 2 to the semiconductor device 1, power is supplied to the internal circuit 4 of the semiconductor device 1 through the resistance element 7. The resistance value of the resistive element 7 is calculated at the time of designing the internal circuit 4 so that the operating current of the internal circuit 4 can be supplied. Further, transistors 5 and 6 are arranged so as to bypass the resistance element 7, and the transistors 5 and 6 input a potential at a connection point A between the resistance element 7 and the internal circuit 4 as a gate voltage, The source is a power supply device 2 and the drain is an n-type transistor connected to point A. When the internal circuit 4 operates normally, power is supplied stably from the transistors 5 and 6.

Next, the operation of the first embodiment will be described. First, when the power supply of the internal circuit 4 and the ground 3 are not short-circuited, the resistance value between the power supply of the semiconductor device 1 and the ground 3 is sufficiently large. , The resistance element 7 does not break and A
The potential at the point does not become the GND potential. As a result, the n-type transistor 5 is turned on, and stable power can be supplied to the internal circuit 4 through the transistors 5 and 6.

On the other hand, when a short circuit occurs between the power supply of the internal circuit 4 and the grounding section 3, the resistance element 7 is disconnected by the current (resistance value × current ² ) flowing through the resistance element itself, and the potential at the point A becomes the GND potential. , That is, Low, the n-type transistors 5 and 6 cannot be turned on, and the power supply to the internal circuit 4 is cut off.

The transistor 6 is one or more transistors configured in parallel with the transistor 5 in order to more stably supply power to the internal circuit. The transistor 6 has a current capacity capable of driving the internal circuit 4 by the transistor 5 alone. Not required if available.

FIG. 2 is a configuration diagram of a burn-in board using the semiconductor device 1 according to the first embodiment, and FIG. 3 is a configuration diagram of a system using the semiconductor device 1 according to the first embodiment. Burn-in board 1 in each case
It is not necessary to configure the protection circuits 23 and 25 as in the conventional example on the mounting board 11 of the system or the system board 11, and the configuration of the burn-in board 10 or the system board 11 can be simplified and inexpensive. Further, since the semiconductor device itself can be separated with a threshold value unique to the semiconductor device 1, it is possible to protect the entire system using the burn-in device and the semiconductor device in detail.

Further, in this embodiment, when a short circuit fault occurs in the internal circuit, the resistance element 7 is cut off from the external power supply.
Separately, by providing the transistor 5 or 6 that stably supplies power to the internal circuit 4 by bypassing the resistance element 7, the stability of power supply when the semiconductor device operates normally can be ensured. .

Embodiment 2 FIG. FIG. 4 is a configuration diagram showing a semiconductor device according to a second embodiment of the present invention. The semiconductor device 1A of this embodiment includes a transistor 14 instead of the resistance element 7 of the first embodiment. The transistor 14 is destroyed by a current flowing when a short circuit occurs in the internal circuit 4 of the semiconductor device, and serves to cut off the power supply to the internal circuit 4. The other configuration is the same as that of the first embodiment, and the description is omitted.

Next, the operation of the semiconductor device of the second embodiment will be described. When power is supplied to the semiconductor device 1A from the power supply device 2, the gate potential of the n-type transistor 14 is supplied by the power supply device 2, and the transistor 14 itself is turned on. At the same time, the potential at the point A rises, and the potential is supplied to the internal circuit 4. Here, when the internal circuit 4 is short-circuited, all the voltage between the power supply and GND is applied between the source and the drain of the transistor 14, and the transistor 1
4 Destroy itself. Also, the transistor 5 to be bypassed
Since the gate potentials of the transistors 5 and 6 cannot be set to High, the transistors 5 and 6 cannot be turned ON, and the power supply to the internal circuit 4 is cut off. On the other hand, when the internal circuit 4 operates normally, the potential at the point A is
Since the potential required for turning ON the transistors 5 and 6 rises, the transistors 5 and 6 also turn ON, and the power can be stably supplied to the internal circuit 4.

As described above, according to the present embodiment, the same effect as in the first embodiment, that is, the internal self-test function can be provided even if a protection circuit is not prepared when a burn-in test or a system is configured. , And a burn-in board or a system mounting board can be simplified.

Further, in addition to the transistor 14 which is cut off from an external power supply when a short-circuit failure occurs in the internal circuit, a transistor 5 or 6 which stably supplies power to the internal circuit 4 by bypassing the transistor 14 is provided. In addition, the stability of power supply when the semiconductor device operates normally can be ensured.

Embodiment 3 FIG. 5 is a configuration diagram showing a semiconductor device 1B according to Embodiment 3 of the present invention. In this embodiment, a p-type transistor 15 and an n-type transistor 16 are connected in series between the power supply device 2 and the internal circuit 4 inside the semiconductor device 1B. The n-type transistors 5 and 6 are connected so as to bypass the p-type transistor 15 and the n-type transistor 16, and a point B between the p-type transistor 15 and the n-type transistor 16 is a gate of the n-type transistors 5 and 6. It is connected to the. Further, the input is set to the potential at the point A, and the output is set to the p-type transistor 1.
A p-type transistor 17 and an n-type transistor 18 constituting an inversion circuit (inverter) having a gate potential of 5 are provided.

Next, the operation of the semiconductor device of the third embodiment will be described. First, when power is supplied to the semiconductor device 1B from the power supply device 2, the gate potential of the n-type transistor 16 becomes H level.
It becomes igh and turns on. Further, since the p-type transistor 15 is normally ON, power can be supplied from the power supply device 2 to the point A via the p-type transistor 15 and the n-type transistor 16. At the point B, since the p-type transistor 15 is on, the potential becomes High, and as a result, the n-type transistor 5
And 6 are turned ON, and stable power supply to the internal circuit 4 is started.

Here, when the internal circuit 4 is short-circuited,
Since the potential at the point A becomes the GND potential, the input of the inversion circuit composed of the p-type transistor 17 and the n-type transistor 18 also becomes the GND potential. As a result, the gate potential of the p-type transistor 15, which is the output of the inversion circuit, becomes High, and the p-type transistor 15 is turned off. Then,
The potential at the point B falls to Low, and the transistors 5 and 6
The power is supplied to the internal circuit 4 by the FF. Also,
Since the p-type transistor 15 is turned off, power is not supplied to the internal circuit 4 from the path of the p-type transistor 15 and the n-type transistor 16.

When the internal circuit 4 is normal, the potential at the point A does not decrease, so that the inversion circuit including the p-type transistor 17 and the n-type transistor 18 does not turn off the p-type transistor 15, and , The transistors 5 and 6 are kept ON, and stable power supply to the internal circuit 4 is performed.

As described above, according to the present embodiment, the same effect as that of the first embodiment, that is, even if a protection circuit is not prepared when a burn-in test or a system is configured, the internal self-test function can be provided by the protection circuit. , And a burn-in board or a system mounting board can be simplified.

In the first or second embodiment, when the internal circuit is short-circuited, the resistor 7 and the transistor 14 constituting the protection circuit are destroyed. In the present embodiment, the transistor constituting the protection circuit is destroyed. Since 15 and 16 are not destroyed, the cause of the failure of the semiconductor device can be analyzed later.

Embodiment 4 FIG. In the first to third embodiments, an example in which an n-type transistor is used as a transistor that bypasses a protection circuit has been described. In this embodiment, an example in which a p-type transistor is used will be described.

That is, as shown in FIGS. 6 and 7, in the configuration of the first embodiment (FIG. 1) and the second embodiment (FIG. 4), p is used as a transistor bypassing the protection circuit.
Type transistor 28 is arranged, and inverting circuit 27 is inserted between point A and the gate of p-type transistor 28.

Further, as shown in FIG.
In the configuration of FIG. 5, a p-type transistor 28 is provided as a transistor that bypasses the protection circuit, and an inverting circuit 27 is inserted between point B and the gate of the p-type transistor 28.

According to the present embodiment, the transistor bypassing the protection circuit is replaced with p-type transistor instead of n-type transistor.
Since the type transistor 28 is employed, a voltage drop corresponding to the threshold voltage (Vth) when the n-type transistor is employed is eliminated, and more stable power can be supplied to the internal circuit 4.

[0037]

As described above, according to the first to sixth aspects of the present invention, the power supply can be cut off by the semiconductor device itself even if a short circuit fault occurs in the internal circuit of the semiconductor device. For example, the burn-in test of another normal semiconductor device can be continuously performed. Further, the burn-in board used for the burn-in test is not destroyed due to a defect in the semiconductor device, so that the maintenance of the burn-in board becomes easy.

Further, since the semiconductor device itself detects a failure in the internal circuit and cuts off the power supply, it is not necessary to prepare a burn-in board for each type of semiconductor device, and the burn-in operation can be simplified.

Further, by using a semiconductor device having the self-test function in a system using the semiconductor device, the system can be protected without providing a protection circuit in the system.

In addition to a protection circuit (resistor, transistor) that cuts off from an external power supply when a short circuit fault occurs in the internal circuit, a switching circuit that bypasses this protection circuit and stably supplies power to the internal circuit is provided. With the provision, power supply stability when the semiconductor device operates normally can be ensured.

According to the fourth aspect of the present invention, as a protection circuit, a transistor element that conducts when a short circuit failure does not occur in an internal circuit, and becomes non-conductive when a short circuit failure occurs, and a protection circuit including the same. Since the combination circuit of the driven inversion circuits is used, when the internal circuit is short-circuited, the transistor forming the protection circuit is not destroyed, and the cause of the failure of the semiconductor device can be analyzed later.

Further, according to the invention of claim 6, since a p-type transistor is used as a transistor of the switching circuit, a voltage drop corresponding to the threshold voltage (Vth) is eliminated, and a more stable power supply is supplied to the internal circuit. Can be.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a burn-in board using the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is a configuration diagram of a system using the semiconductor device according to the first embodiment of the present invention;

FIG. 4 is a circuit diagram showing a semiconductor device according to a second embodiment of the present invention.

FIG. 5 is a circuit configuration diagram showing a semiconductor device according to a third embodiment of the present invention.

FIG. 6 is a circuit configuration diagram showing a semiconductor device according to a fourth embodiment of the present invention.

FIG. 7 is a circuit configuration diagram showing a semiconductor device according to a fourth embodiment of the present invention.

FIG. 8 is a circuit configuration diagram showing a semiconductor device according to a fourth embodiment of the present invention.

FIG. 9 is a schematic configuration diagram showing a conventional semiconductor device.

FIG. 10 is a diagram illustrating power supply connection during burn-in by a conventional semiconductor device.

FIG. 11 is a diagram in which a conventional semiconductor device is arranged on a burn-in board.

FIG. 12 is a system configuration diagram of a conventional semiconductor device.

[Explanation of symbols]

1, 1A, 1B semiconductor device, 2 power supply device, 3GN
D, 4 internal circuit, 5, 6 n-type transistor, 7 resistor, 8 burn-in board GND wiring, 9 burn-in board power supply wiring, 10 burn-in board, 1
1 System mounting board, 12 Power wiring of system mounting board, 13 G of system mounting board
ND wiring, 14 n-type transistor, 15 p-type transistor, 16 n-type transistor, 17 p-type transistor, 18 n-type transistor, 27 inversion circuit, 28
p-type transistor.

Claims (7)

[Claims] A protection circuit connected between an external power supply and an internal circuit of the semiconductor device, wherein the protection circuit disconnects the internal circuit from the external power supply when a short circuit occurs in the internal circuit; and bypasses the protection circuit. A switching circuit connected to the internal circuit, for stably supplying power to the internal circuit when a short circuit failure does not occur in the internal circuit, and stopping power supply to the internal circuit when a short circuit failure occurs in the internal circuit. A semiconductor device characterized by incorporating therein. 2. The semiconductor device according to claim 1, wherein the protection circuit includes a resistance element that is disconnected when a short circuit fault occurs in the internal circuit. 3. The semiconductor device according to claim 1, wherein the protection circuit includes a transistor that breaks down when a short circuit occurs in the internal circuit. 4. A combination of a transistor element and an inverting circuit driving the transistor element, wherein the protection circuit conducts when a short-circuit failure does not occur in the internal circuit, and turns off when a short-circuit failure occurs. The semiconductor device according to claim 1, wherein the semiconductor device is a circuit. 5. The switching circuit according to claim 1, wherein the switching circuit includes a transistor that is turned on when a short circuit fault does not occur in the internal circuit, and that is turned off when a short circuit fault occurs in the internal circuit. The semiconductor device according to claim 1. 6. The inversion of turning on the transistor when a short circuit failure does not occur in the internal circuit and turning off the transistor when a short circuit failure occurs in the internal circuit. The semiconductor device according to claim 5, further comprising a circuit. 7. The semiconductor device according to claim 5, wherein a plurality of transistors of the switching circuit are provided in parallel so as to bypass the protection circuit.