JPS58219771A - Integrated circuit - Google Patents

Abstract

PURPOSE:To prevent erroneous operation when a circuit is not operated, by providing a means, by which an MOS integrated circuit is made to be a nonconductive state when the circuit is not operated, on the side of one power source, and providing a bypass means between the output of the nonconductive means and another power source. CONSTITUTION:An MOS transistor 4 is inserted between a positive power source side terminal 1 and an internal circuit 5, and a voltage at a gate electrode terminal 6 is controlled. In this way, nonconduction and conduction to the internal circuit 5 are controlled. A bypass circuit 17 is provided between the source electrode of the transistor 4 and a negative electrode 2. The bypass circuit 17 operates as a bypass circuit when the negative power source 2 is opened and becomes the ground potential. Thus an erroneous operation is not generated in the internal circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an integrated circuit, and more particularly to an improvement of an MO8 integrated circuit which is rendered non-conductive during non-operation to reduce power consumption.

The development of MO8 integrated circuits is beginning to penetrate analog integrated circuits that traditionally used bipolar technology. This is probably because, with the development of circuit design technology and process technology, it has become possible to reduce the input offset voltage, which is one of the basic characteristics of analog circuits. Furthermore, there is an increasing demand for the development of integrated circuits in which analog and digital circuits coexist, and MO8 integrated circuits, which have been conventionally applied to digital circuits, are increasingly being used in the analog field.

In this way, an MO8 integrated circuit incorporating an analog circuit requires two positive and negative power supplies and a ground terminal. Since this 2t source is used, control to make it non-conductive during non-operation becomes complicated. Normally, in order to make the device non-conductive, one voltage is generally supplied to the internal operating circuit through the external power supply terminal and the υMOS transistor. Said M
O8) The transistor is configured so that the gate electrode is in the ON state during operation. For example, in an N-channel MO84 product circuit, the non-conducting means is provided on the positive power supply side, and the gate electrode of the MOS transistor is connected to the positive power supply during operation, and to the negative power supply during non-operation. It is clear that controlling conduction and non-conduction in the operating state contributes to a reduction in power consumption and is an advantage in device design.

However, a MOS integrated circuit using two positive and negative power supplies has a drawback in the non-conducting means.

For example, considering an N-channel MOS integrated circuit as an example, a circuit as shown in FIG. 1 can be considered. In Figure 1, 1
is a positive power supply, 2 is a negative power supply terminal, and 3 is a connection terminal. By inserting a MOS transistor 4 between the positive power supply terminal 1 and the internal circuit 5 and controlling the voltage of the gate electrode terminal 6, υ
It controls non-conduction and conduction to the internal circuit 5. In such a circuit, there is no problem with the control voltage of the M''OS transistor 4 when the positive and negative power supplies are connected, but when the negative power supply is in an open state and the potential of the gate electrode 6 becomes the ground potential, the MOS transistor Gate electrode 6, which is the control terminal of 4, is grounded.

Normally, the MOS transistor 4 uses a Teplissian transistor, and its threshold voltage is negative, so the voltage of the source electrode of the MOS transistor 4, that is, the internal circuit 5, is positive. Voltage was applied via the MOS transistor 4 to a portion of the internal circuit 5 that operated between the positive power supply and the ground, sometimes resulting in malfunction. This is MOS
) The transistor 4 operates at the semi-threshold level, and the internal
This is because, even if the device operates in the quasi-threshold region, digital output will be performed while the internal operation remains unresolved.

An object of the present invention is to eliminate such malfunctions, stabilize the non-conducting state during non-operation, and provide a 40S integrated circuit that does not malfunction.

Embodiments of the present invention will be described in detail below using the drawings.

FIG. 2 is a detailed explanatory diagram of the present invention, and the same numbers are used for the same parts as in FIG.

The difference between FIG. 2 and FIG. 1 is that a bypass circuit 17 is connected between the source electrode of the λ108 transistor 4 and the negative power supply 2. The bypass circuit 17 operates as a bypass circuit for the MOS transistor 4 when the negative power supply 2 is opened and becomes the first ground type, and has a function that prevents the internal circuit 5 from malfunctioning. This bypass circuit 1
7 allows the MOS integrated circuit to operate stably even when the negative power supply is open, so this effect is useful.

Examples of bypass circuits are shown in FIGS. 3(a) to 3(C). Third
Figure (a) shows the case where a depletion transistor is used with the gate connected to terminal 2, Figure (c) shows the case of using an encoder MOS transistor with the gate connected to the drain. This is the case when a resistor is used.

Although this embodiment is explained using an N-channel type MO8 integrated circuit as an example, the same applies to a P-channel type, and can be easily considered by reversing the positive and negative power supplies and making the control voltage have the opposite polarity. It's obvious that it's hard. Note that the bypass circuit 17 may be any circuit as long as it can bring the voltage of the source electrode of the MOS transistor 4 sufficiently close to the open negative power supply 2.

As described above in detail with reference to the drawings, the present invention allows MOS integrated circuits that are non-conductive during non-operation to be designed to prevent malfunctions. It is valid.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional circuit diagram, and FIG. 2 is a detailed explanatory diagram of the present invention. FIGS. 3(a) to 3(C) are diagrams showing examples of bypass circuits. 1...Positive power supply, 2...Negative power supply, 3...
...Ground terminal, 4...MOS) transistor, 5...Internal circuit, 6...Control terminal,
17... Bypass circuit. (b) 4≦ (C di

Claims (1)

[Claims] In MO8 integrated circuits using dual power supplies, M
1. An integrated circuit comprising means for rendering the O8 integrated circuit non-conductive on one power supply side, and bypass means provided between the output of the non-conducting means and the other power supply.