JPH0248846A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To prevent the occurrence of circuit interference by arranging plural 1st and 2nd block areas are arranged alternately. CONSTITUTION:Two (in general, plural number) 1st block areas 31, 32 and two 2nd block areas 33, 34 are arranged alternately. Thus, when an FM tuner circuit being the 1st electronic block circuit is in operation, an AM tuner circuit being the 2nd electronic block circuit is stopped, then the 2nd block areas 33, 34 where AM-RF blocks are AM-IF blocks are integrated respectively reach a high impedance and the mutual interference between the 1st block areas 31, 32 where an FM front end block and an FM-IF block are integrated respectively is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a semiconductor integrated circuit in which circuit blocks such as an FM/AM tuner having different signal frequencies and signal levels are formed on the same semiconductor substrate.

(b) Conventional technology Electronic devices such as TV tuners and FM/AM tuners are
Since the audio signal is extracted from the F (Radio Frequency) signal, the frequency of the signal handled by each circuit block divided by function is often different. For example, an FM tuner for Japan only has an RF signal of 76 to 9
0MHz, the intermediate frequency signal is 10.7MHz, and 2
Audio signals from 0 to 20,000Hz and 20Hz to 9
A wide range of signals of 0 MHz will be handled.

An example of the above FM/AM tuner is shown in FIG. The mixing circuit (2M7028121 circuit that converts the frequency to an intermediate frequency by mixing in 3), (4) amplifies and limits the amplitude of the intermediate frequency signal (IF multiplied signal, and detects it to obtain an audio signal (AF multiplied signal) FM/IF amplifier circuit,
(5) is a noise canceling circuit having a function such as that described in Japanese Patent Publication No. 62-21461; (6)
(7) is a multiplex circuit that demodulates L channel and R channel signals in the case of stereo broadcasting, and (7) is an AM tuner circuit that selects AM broadcasting and outputs an audio signal. For example, in the case of FM broadcast reception, the RF multiplied signal input from the antenna (8) and high frequency amplified by the RF amplifier circuit (9) is output from the local oscillation circuit (2) of the 2M7028121 circuit (1). (
By mixing in the mixing circuit (3) of 1), 2M702
By outputting an IF multiplied signal from the 8121 circuit (1) and detecting the IF multiplied signal by the detection circuit of the FM/IF amplifier circuit (4), a composite signal is output from the FM-IF amplifier circuit (4). , a multiplex circuit (6) outputs L channel and R channel audio signals to output terminals (10), respectively. An FM tuner circuit having such a configuration is described, for example, in ``88 Sanyo Semiconductor Data Book, Bipolar Integrated Circuits for Portable Audio Edition, J, page 152, published on December 10, 1988.

Incidentally, electronic devices in recent years are required to be more and more compact and high-performance, and accordingly, the circuit shown in FIG. 3 is being made into a single chip as much as possible. However, in the above example of the FM tuner, the 2M7028121 circuit (1) is several tens of M
Since it handles high frequency signals of Hz, interference with other circuits is likely to occur due to unnecessary radiation.

Furthermore, since a weak level signal from the antenna (8) is handled, the circuit operation tends to become unstable due to interference with other circuit blocks, and in severe cases, oscillation occurs. Therefore, 2M
It was extremely difficult to integrate the 7028121 circuit (1) into a single chip.

(c) Problems to be Solved by the Invention As described above, conventionally there has been a drawback that it is extremely difficult to integrate the 2M7028121 circuit (1) because circuit interference is likely to occur.

(d) Means for Solving the Problems The present invention has been made in view of the above drawbacks, and consists of a first electronic block circuit having a predetermined function divided into a plurality of integrated circuits of substantially the same size. n first block regions and m-th electronic block circuits of substantially the same size, which are integrated into a plurality of second electronic block circuits that are different in function from the first electronic block circuits and do not operate simultaneously; This problem is solved by alternately arranging the n first block areas and the m second block areas.

(*) Effect According to the present invention, when the first electronic block circuit is operating, the second electronic block circuit is not operating. The second block area has high impedance, and mutual interference between the plurality of first block areas can be prevented.

Further, the second ground line between the plurality of first block regions serves as a line exclusively for absorbing the separation region, and it is possible to prevent mutual interference between the plurality of first block regions.

(F) EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

First, there are first and second electronic block circuits, and n first block areas (31), (32) are formed by dividing the first and second electronic block circuits into a plurality of parts and integrating them.
) and m second block areas (33).

There is (34).

These n first block areas (31), (32)
The m second block areas (33) and (34) are hatched areas, and the first block areas (31) and (32) are the FM front end block and the FM-IF block. In the second block areas (33) and (34), an AM-RF block and an AM-IF block area are formed. Here m
Although n is set to 2, it may be 2 or more.

Also, from the upper end of the semiconductor chip (35), there is a first block area (31) where the FM front end block is integrated.
is placed, and then the second AM-RF block is integrated.
A block area (33) of FM-I F
A first block area (32) in which blocks are integrated is arranged, and finally a second block area (34) in which AM-IF blocks are integrated is arranged. Also, the four block areas (31), (32), (33)
, (34) are formed to have substantially the same size.

ing.

The above-described configuration is a feature of the present invention, and includes the two first block areas (31>, (32) and the second block area).
The second block area (33) and (34) are arranged alternately.

In other words, when the FM tuner circuit, which is the first electronic block circuit, is operating, the AM tuner circuit, which is the second electronic block circuit, is stopped, so that the AM-RF
The second block areas (33) and (34) where the AM-IF block and AM-IF block are integrated have high impedance, and the FM front-end block and the FM-IF block are integrated.
A first block area in which IF blocks are integrated (
Mutual interference between (31) and (32) can be prevented.

Furthermore, the AM tuner block itself has a huge capacity. This consists of an N-type epitaxial layer (36), a P-type isolation region (37), an N-type epitaxial layer (36), and a P-type semiconductor substrate (38), like the capacitor shown in Figure 2.
It is formed by Therefore, the first block area (31
) and the first block region (32) respectively from the semiconductor substrate (
38), even if high frequency noise enters into the second block area (38), the huge capacitance is between this first block area (31) and the first block area (32), so this high frequency noise will be transmitted to the second block area. (33) is applied to the power line (3
9) and each block area (31),
High frequency noise does not enter (32) and interference can be prevented.

Further, a ground line dedicated to each block is provided between the first block area and the second block area.

That is, the first block area (31) in which the FM front end block and the FM-IF block are formed;
(32) and a first ground line (40) around it.

(41) is provided, and an AM-RF block and an AM-RF block are provided.
Second block area (33) where the IF block is formed
, a second ground line (42) around (34)
.

(43) is provided. And the respective ground lines (40), (41), (42), (43
) are the isolation regions ( ) reaching the semiconductor substrate (38), respectively.
37) is in ohmic contact with.

On the other hand, the first power supply line is also connected to the first block area (31
), (32) are provided with (44), (45), and the second block areas (33), (34) are provided with a second power supply line (39).

(46) is provided.

Also, since the first electronic block circuit and the second electronic block circuit do not operate at the same time, ts, line (39),
(44) extends in parallel from pad 'l'l:C1, and ground lines (40) and (42) extend in parallel from GND. Also TFI line (45),
(46) extends in parallel with VCC*, and ground lines (41) and (43) extend in parallel with σD.

Here, the first ground line (40) and the second ground line (42) are connected in parallel to GND, and the first ground line (41) and the second ground line (43) are connected in parallel to GND. *Extends to. In other words, since it is connected to the pad in parallel with another line, there is no common impedance, so the second ground line (42>
, (43) can flow to GND and GND*, respectively, without affecting the first ground lines (40) and (41).

Therefore, during FM operation, the AM-RF block and AM-
Since the IF block is not operating, the second block area (33) is the first block area (31), (
32), and the second ground line (42) dedicated to AM-RF becomes a line dedicated to absorption.

On the other hand, when AM is operating, the FM front end block and FM-IF block are not operating, so the first block area (32) is the second block area (33).
, (34) becomes high impedance, and FM-I
F/mouth, the first ground line (41) dedicated to ivy becomes a line dedicated to blotting.

Although the two-mode reception of FM and AM has been discussed here, this application generally applies when two electronic block circuits do not operate at the same time, and furthermore, when there are blocks in the same electronic block circuit that do not want to interfere with each other. Applicable.

(G) As described in detail, according to the present invention, when a plurality of first block areas and a plurality of second block areas are arranged alternately, the first block area (31) and ( 32), since the second block areas (33) and (34) are separated by the second block area (33) and the first block area (32), respectively, noise intrusion that causes mutual interference is prevented. Also, when the FM is operating, the second block area (33) becomes a high impedance, and it is possible to prevent negative layer noise from entering.
Mold epitaxial! (36) P-type substrate (38),
N-type epitaxial calendar (36) and P”-type separation region (
37), and since the second block regions (33) are connected to the second power supply lines (39), high-frequency noise passing through the second block regions is suppressed. It is absorbed by this second power supply line (39).

Therefore, mutual interference between the first block areas (31) and (32) can be prevented.

Furthermore, a ground line (42) dedicated to the second block area (33) is provided between the first block areas (31) and (32), and this ground line (42) is used to separate the P+ type. It is in ohmic contact with the area (37). Therefore, from the first block area (31) where the FM front end block is integrated to the first block area (32) where the FM-IF block is integrated, or vice versa. The leakage current flowing from (32) to (31) in the direction of (32) can be absorbed.

Therefore, the FM tuner block circuit is divided into multiple parts, and here the FM front end block and FM front end block, which do not want to interfere with each other, are
- divide into IF block, divide AM tuner block circuit into AM-RF block and AM-IF block,
By alternately arranging these blocks, mutual interference between the FM front end block and the FM-IF block can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a semiconductor integrated circuit according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view taken along line AA' in FIG. 1,
FIG. 3 is a block diagram of the FM/AM tuner. (31), (32)...first block area,
(33), (34)... second block area,
(35)...Semiconductor chip, (36)...Epitaxial layer, (37)...Isolation region, (38)...
・Semiconductor substrate, (39)...second power line, (
40), (41)...first ground line, (42
), (43)...second ground line, (4
4), (45)...first power line, (46
)...Second power line.

Claims (6)

[Claims] (1) n first block regions of substantially the same size in which a first electronic block circuit having a predetermined function is divided into a plurality of parts and integrated, and the first electronic block circuit has a different function from the first electronic block circuit; m second block areas of substantially the same size in which second electronic block circuits that do not operate simultaneously are divided and integrated; A semiconductor integrated circuit characterized in that two block regions are arranged alternately. (2) A first ground line and a second ground line dedicated to the first electronic block circuit and the second electronic block circuit are provided between the first block area and the second block area; 2. The semiconductor integrated circuit according to claim 1, wherein the first ground line and the second ground line are in ohmic contact with an isolation region reaching the semiconductor substrate. (3) The first power line and second power line dedicated to the first electronic block circuit and the second electronic block circuit, and the first ground line and second ground line have a two-layer wiring structure. 3. A semiconductor integrated circuit according to claim 2. (4) n FM tuner block areas of substantially the same size obtained by dividing the FM tuner block into multiple parts and integrating them, and m AM tuner blocks of substantially the same size by dividing the AM tuner block into multiple parts and integrating them. What is claimed is: 1. A semiconductor integrated circuit comprising: a semiconductor integrated circuit comprising: a semiconductor integrated circuit comprising: a semiconductor integrated circuit; and wherein the n FM tuner block regions and the m AM tuner block regions are alternately arranged. (5) A first ground line and a second ground line dedicated to the FM tuner block and AM tuner block are provided between the FM tuner block area and the AM tuner block area, and the first ground line and the second ground line are 5. The semiconductor integrated circuit according to claim 4, wherein the second ground line is in ohmic contact with an isolation region reaching the semiconductor substrate. (6) The first power line and second power line dedicated to the FM tuner block and AM tuner block, and the first ground line and second ground line have a two-layer wiring structure. The semiconductor integrated circuit described.