JPH0232414A - Over-current limiting circuit - Google Patents

Abstract

PURPOSE:To prevent the destruction of a semiconductor integrated circuit due to the over-current by mounting an over-current limiting circuit on the semiconductor integrated circuit. CONSTITUTION:A current from the power source module of a semiconductor integrated circuit is supplied through a power source supplying line 11A to a current limiting means 12. The means 12, only when a control command S from a comparing means 13 is eliminated, supplies the current through a power source supplying line 11B to a current detecting means 14 without adding a limit to the current supplied from the line 11A. The means 14 passes the current to a power source supplying line 11C and detects a value I of the pass ing current. The current value I is inputted to the comparing means 13 and compared with a passing current limit value I0. When I is I0 or above, the means 13 outputs the limit command S to the limit means 12 and the means 12 limits the current supplied to a line 11B to the limit value I0.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to power supply for semiconductor integrated circuits, and particularly to an overcurrent limiting circuit for limiting overcurrent thereof.

[Conventional technology]

Generally, a digital circuit of an information processing system is composed of a plurality of semiconductor integrated circuits, and power is supplied to these plurality of semiconductor integrated circuits from a power supply unit. This power supply unit consists of a plurality of power supply modules, and each power supply module supplies power to the plurality of semiconductor integrated circuits that it is responsible for.

Overcurrent detection in such an information processing system is performed by detecting overcurrent of each power supply module using an overcurrent detection mechanism provided in a power supply unit.

[Problem to be solved by the invention]

However, since overcurrent detection by the above-mentioned overcurrent detection mechanism mainly detects overcurrent of each power supply module,
Overcurrents in individual semiconductor integrated circuits cannot be detected. Therefore, even if an overcurrent occurs for one semiconductor integrated circuit, it is a slight increase from the power supply module's perspective, so such an overcurrent may not be detected.

Furthermore, if the overcurrent detection mechanism fails and overcurrent detection becomes impossible, a large amount of current may flow into the semiconductor integrated circuit, potentially destroying the semiconductor integrated circuit.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an overcurrent limiting circuit that can detect overcurrents in individual semiconductor integrated circuits and prevent damage to the semiconductor integrated circuits due to overcurrents.

[Means to solve the problem]

The overcurrent limiting circuit of the present invention is implemented in each semiconductor integrated circuit, and includes a current detection means for detecting an inflow current value flowing into the semiconductor integrated circuit, and a predetermined overcurrent value and an inflow current value detected by the current detection means. a comparison means for comparing the inflow current with a current limit value, and a current limiter for limiting the inflow current to the overcurrent limit value when it is determined that the inflow current value is equal to or higher than a predetermined overcurrent limit value as a result of the comparison between the comparison means. It is characterized by consisting of.

[Effect]

Overcurrent is detected in each semiconductor integrated circuit, and the inflow current flowing into the semiconductor integrated circuit is limited to the overcurrent limit value.
It is possible to prevent destruction such as burnout of semiconductor integrated circuits and improve the safety of information processing systems.

〔Example〕

FIG. 1 is a block diagram of an overcurrent limiting circuit according to the present invention. Current from the power supply module is supplied to the current limiting means 12 through the power supply line 11A. Current limiting means 12
is supplied to the current detection means 14 via the power supply line 11B without limiting the current supplied from the power supply line 11A unless there is a restriction command S from the comparison means 13.

The current detection means 14 allows the current supplied from the power supply line 11B to pass through the power supply line 11C, and detects the value I of the passing current. The current value I detected here is input to the comparison means 13, and is determined as a predetermined overcurrent limit value I. compared to

In the comparison means 13, the detected current value ■ is the predetermined overcurrent limit value I. If this is the case, a limiting command S is output to the current limiting means 12. On the other hand, when the current value I is less than the overcurrent limit value 10, the limit command S is not output.

When the limit command S is manually input to the current limiter 12, the current limiter 12 limits the current supplied from the power supply line 11A, and the current supplied to the power supply line 11B is reduced to the overcurrent limit value I. limited to.

As a result, the current flowing through the power supply line 11C reaches the overcurrent limit value I. Therefore, the current flowing into the semiconductor integrated circuit can be prevented from becoming excessive.

Next, FIG. 2 is an explanatory diagram when the overcurrent limiting circuit of the present invention is mounted on the semiconductor integrated circuit 15. Power is supplied to the information processing circuit 16 of the semiconductor integrated circuit 15 through the power supply line 11C. It will be done. That is, the information processing circuit 16
The overcurrent limiting circuit of the present invention is provided upstream of the power supply line 11C. Thereby, the information processing circuit 16 that forms the core of the semiconductor integrated circuit 15 can be protected.

〔Effect of the invention〕

As described above, according to the present invention, by mounting an overcurrent limiting circuit on a semiconductor integrated circuit, it is possible to prevent excessive current from flowing into the semiconductor integrated circuit. In addition, it is possible to protect not only the semiconductor integrated circuit but also components such as a package attached to the semiconductor integrated circuit without providing a special protection circuit externally.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the overcurrent limiting circuit of the present invention, and FIG. 2 is an explanatory diagram of the overcurrent limiting circuit of the present invention implemented in a semiconductor integrated circuit. 11... Power supply line, 12... Current limiting means, 13... Comparing means, 14...
Current detection means, 15... semiconductor integrated circuit, 16... information processing circuit. Applicant NEC Corporation Representative Patent Attorney Umeo Yamauchi

Claims (1)

[Claims] A current detecting means that is mounted on each semiconductor integrated circuit constituting a digital circuit of an information processing system and detects an inflow current value flowing into the semiconductor integrated circuit, and a predetermined inflow current value detected by the current detecting means. a comparison means for comparing the inflow current value with an overcurrent limit value; and a current that limits the inflow current to the overcurrent limit value when the comparison means determines that the inflow current value is greater than or equal to the overcurrent limit value. An overcurrent limiting circuit consisting of limiting means.