JPH05190670A - Semiconductor integrated circuit device - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to reduce noise without increasing the size of a semiconductor integrated circuit device. A digital circuit driven by a first drive power supply and a first ground power supply, and a power supply line driven by a second drive power supply and a second ground power supply different from the first drive power supply and the ground power supply. And an analog circuit having a connection cell 17 and a corner cell 15, one end of which is connected to the second drive power supply and the other end of which is connected to the second drive power supply in at least one of the power supply line connection cell and the corner cell. Two
It is characterized in that a capacitor 25 connected to the ground power source is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device having an analog circuit and a digital circuit formed on one chip.

[0002]

2. Description of the Related Art Generally, in a semiconductor integrated circuit device in which an analog circuit and a digital circuit are formed on one chip, noise caused by turning on and off the digital circuit may affect the analog circuit and cause characteristic deterioration. Therefore, as shown in FIG. 2, the conventional semiconductor integrated circuit device 3
In the case of 0, the ground power supply and the drive power supply of the digital circuit and the analog circuit are separated and independent, and the noise is taken by providing the capacitor 25 between the drive power supply line and the ground power supply line in the analog internal circuit cell 21. Was there. In FIG. 2, the digital circuit includes a ground power supply pad 2a, a drive power supply pad 2b, a data input pad 2c, a data output pad 2d, a ground power supply line 3, a drive power supply line 4, and a digital internal circuit 5. There is. The analog circuit includes a ground power supply line 10, a drive power supply line 11, an input cell 13, an output cell 14, a corner cell 15, a reference level input cell 16, a power supply line connection cell 17, a drive power supply cell 18, and a ground power supply. The cell 19 and the analog internal circuit cell 21 are provided. Power supply separation cells 7 and 8 are provided between the analog circuit and the digital circuit.

[0003]

As described above, in the conventional semiconductor integrated circuit device, the analog internal circuit cell 21 is used.
Although a countermeasure against noise is taken by providing the capacitor 25 therein, it is necessary to increase the capacitance of the capacitor in order to reduce noise. Analog internal circuit cell 21
When the capacitor 25 having a large capacitance is provided therein, the size of the internal circuit cell 21 becomes large, which causes a problem that the semiconductor integrated circuit device 30 also becomes large. The present invention has been made in consideration of the above circumstances, and an object thereof is to provide a semiconductor integrated circuit device capable of reducing noise without increasing the size of the semiconductor integrated circuit device.

[0004]

A semiconductor integrated circuit device according to the present invention comprises a digital circuit driven by a first drive power source and a first ground power source, and a digital circuit driven by the first drive power source and the ground power source. An analog circuit which is driven by two driving power supplies and a second ground power supply and has a power supply line connecting cell and a corner cell, and is provided in at least one of the power line connecting cell and the corner cell. A capacitor having one end connected to the second drive power supply and the other end connected to the second ground power supply is provided.

[0005]

According to the semiconductor integrated circuit device of the present invention having such a configuration, the noise reducing capacitor is provided in at least one of the power source connecting cell and the corner cell of the analog circuit. On the other hand, since the cell has a sufficient space, it is possible to increase the capacitance of the capacitor without increasing the size of the semiconductor integrated circuit device, which can reduce noise.

[0006]

1 shows an embodiment of a semiconductor integrated circuit device according to the present invention. A semiconductor integrated circuit device (hereinafter, referred to as a circuit device) 1 of this embodiment includes a digital circuit and an analog circuit.

The digital circuit includes a ground power supply pad 2a,
A drive power supply pad 2b, a data input pad 2c, a data output pad 2d, a ground power supply line 3, a drive power supply line 4, and a digital internal circuit 5 are provided. The analog circuit includes a ground power supply line 10, a drive power supply line 11,
Input cell 13, output cell 14, corner cell 15, reference level input cell 16, power supply line connection cell 17,
A drive power supply cell 18, a ground power supply cell 19, and an analog internal circuit cell 21 are provided. Power supply separation cells 7 and 8 are provided between the analog circuit and the digital circuit. Further, the input cell 13 is the input pad 13a.
The output cell 14 has an output pad 14a, and the reference level input cell 16 has a reference level input pad 16a.

In order to reduce noise, the power supply line connecting cell 17 is provided with a capacitor 25 having one end connected to the drive power supply line 11 and the other end connected to the ground power supply line 10. The drive power supply cell 18 is provided with a drive power supply pad 18a, and the ground power supply cell 19 is provided with a ground power supply pad 19a. As mentioned above,
In the circuit device 1 of the present embodiment, the size of the analog internal circuit cell 21 can be made smaller than the conventional one by providing the noise reducing capacitor 25 in the cell 17 for connecting the power supply line. .. Also, cell 17
Has a sufficient space, it is possible to increase the capacity of the capacitor 25 provided in the cell 17. As a result, noise can be reduced without increasing the size of the circuit device.

Although the noise reducing capacitor 25 is provided in the power line connecting cell 17 in the above embodiment,
The same effect can be obtained by providing it in the corner cell 15 instead of providing it in the cell 17.
You may provide in 5,17. Further, as a capacitor for reducing noise, it is possible to form a transistor and use the capacitance between the gate and the channel of this transistor.

[0010]

According to the present invention, noise can be reduced without increasing the size of the semiconductor integrated circuit device.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a semiconductor integrated circuit device according to the present invention.

FIG. 2 is a plan view of a conventional semiconductor integrated circuit device.

[Explanation of symbols]

 1 semiconductor integrated circuit device 3 ground power supply line for digital circuit 4 drive power supply line for digital circuit 5 digital internal circuit 7, 8 power supply separating cell 10 analog circuit ground power supply line 11 analog circuit drive power supply line 13 analog circuit input Cell 14 analog circuit output cell 15 corner cell 16 analog circuit reference level input cell 17 analog circuit power supply line connection cell 18 analog circuit drive power supply cell 19 analog circuit ground power supply cell 21 analog internal circuit cell 25 capacitor

Claims (1)

[Claims] 1. A digital circuit driven by a first drive power supply and a first ground power supply, and a digital circuit driven by a second drive power supply and a second ground power supply different from the first drive power supply and the ground power supply. An analog circuit having a power supply line connection cell and a corner cell, wherein one end is connected to the second drive power supply in at least one of the power supply line connection cell and the corner cell. A semiconductor integrated circuit device having a capacitor whose end is connected to a second ground power supply.