JPS5843624A - Semiconductor integrated circuit device - Google Patents

Abstract

PURPOSE:To prevent breakdown of a transistor due to static electricity without exerting no influence at the time of operation, by connecting a depression type transistor between a terminal of an integrated circuit, and ground and an electric power supply. CONSTITUTION:Between an output terminal 1-6, and ground and an electric power supply VCC, depression type transistors 1-1, 1-2 are connected, respectively. A base potential generating circuit 1-5 is constituted so that base potential VS becomes the same potential as the ground potential, in a state that the electric power supply VCC is not turned on. In this state, even if high voltage caused by static electricity is generated in an output terminal 3-6, a current flows through a resistance 3-1 or 3-2, on high voltage is applied between the source and the gate of an internal transistor 3-3, or between the drain and the gate of a transistor 3-4, and they are protected against a high potential pulse, etc. from the outside. Subsequently, in case when the electric power supply VCC has been turned on and the device has entered into the operating state, said transistors 1-1, 1-2 can be neglected, and no influence is exerted on an output.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulated gate lid field effect transistor (hereinafter referred to as M
The present invention relates to a semiconductor integrated circuit device using a transistor (referred to as a transistor), and a semiconductor integrated circuit device incorporating a JIK-improved protection circuit.

Generally, in semiconductor devices using MO811) transistors, the transistors may be destroyed by static electricity.

For this reason, methods such as connecting a resistor or the like to the input/output terminals are used as a protection measure. However, with the method of using a resistor, for example, when inserting this resistor into an input terminal, the resistance value must be set to a value of Ω or more in order to have an effect, and therefore it cannot be used for input terminals that require high-speed switching characteristics. The shortcomings were obvious. In addition, when inserting it into the output terminal, the voltage drop due to the inserted resistance will cause the output level to be 0@
It had the disadvantage of deteriorating sexuality.

The present invention overcomes the above-mentioned conventional drawbacks and provides a semiconductor integrated circuit device having input/output terminals without deterioration of the switching characteristics of the input terminals, without deterioration of the output level of the output terminals, and without being destroyed by static electricity. The purpose is to provide the following.

That is, a depletion lid transistor is connected between a terminal of an integrated circuit constituted by an M08[) tunister and 11j111 (hereinafter referred to as GND) or between a power supply, and a gate electrode of the depletion lid transistor is connected to GND, Said Despres, C.

This conductor device is characterized by incorporating a base potential generation circuit that generates a base potential that causes the double transistor to become non-conductive.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows an embodiment according to the present invention.

FIG. 1 shows a device in which a depletion type transistor is connected between the output terminal, GND, and the power supply.

In Figure 1, 1-1.1-2 is depression
1-3.1-4 is an enhancement IINch) transistor, and l-5 is a base potential generation circuit. Transistors t-x, 1-2 have a base potential VsK
t': 11 As shown in the curve shown in Figure 2, the threshold voltage v
Te changes.

The VCX-SO base potential connection is configured so that when the power supply VCC is not turned on, the voltage is the same as the ground potential. At this time, the transistor -1* 1-
! i() Vt as 211OVtt tehD s
), transistor 1-1*1-2 acts as a resistor. This shows the 38th!1 company's O#O status. In Fig. 3, even if a high voltage that contributes to static electricity is generated at the output terminal 1-6' at 11F, current flows through the resistor 3-1 or 3-2, and the source of the internal transistor 3-3. A high voltage is not applied between the drain and gate of the cross-shaped transistor 3-4, and the transistor 3-4 is protected from external high potential pulses.

Next, when Ktl[Vcc is turned on and enters the operating state, !
The base potential vI■vsw is determined by the I-board potential generation circuit 1-5.
When m is generated, the transistor -1,1--40v!
becomes the second Et)Vtl. At this time, the transistor -
1, 1-1 is a high invidae vagina jjllllml
is equal to the fourth figure. That is, operation line 1111 state KTh''1 ・□・j stripe 1100) 9ydx#1-
1.1-2 does not give II/AII''e self-output Kl effect. As mentioned above, according to the single-source Ij1, it does not affect operation, and when not in use, for example, L8I It is possible to prevent the transistor □ from being destroyed by static electricity during storage and transportation.

Although this embodiment is a case in which the present invention is applied to an output terminal, it is of course possible to obtain the same effect even if the present invention is applied to an input terminal.

[Brief explanation of drawings]

Figure 1 shows an embodiment of the present invention where wJ%j12WJ is □
≠ A diagram showing the relationship between Vt and base potential of the pre- and current switch metals. Figure 3 is a diagram showing the equivalent circuit of the output terminal section of Figure 1 before power is turned on. Figure 4 is a diagram showing the equivalent circuit of the output terminal section of Figure 1 before power is turned on. 2 is a diagram showing one equivalent path of the output terminal section of FIG. 1. FIG. In addition, in the figure, 1-1.1-2...-Depres. '/W 3/I! NCh) Tunjista, 1-3.1
-4.1-3.3-4.4-3.4-4...Enhancement 1llNch) Tunister, 1-5.
Old・-Base potential generation circuit, 1-6, 3-6 I 4-
6----"-output terminal, 3-113-2""-'depreff VW yllNch ) transistor replacement resistor. Figure 2 Figure 3 Leap-4 Figure 4

Claims (2)

[Claims] (1) In a semiconductor integrated circuit device configured with an insulated gate field effect transistor, a depressing type transistor is connected between a terminal of the integrated circuit and the ground, and a gate electrode of the depressing type transistor is connected to the grounding. . A semiconductor device comprising a built-in base potential generation circuit that generates a base potential that causes the depletion history transistor to become non-conductive. (2) A semiconductor integrated circuit device according to claim (1), characterized in that a double-sided, thin-type transistor is connected between a terminal of the integrated circuit and a power supply.