JPS6017939Y2 - integrated circuit device - Google Patents

Description

[Detailed explanation of the invention] This invention is a semiconductor integrated circuit incorporating a power amplifier circuit,
In particular, the present invention relates to a semiconductor integrated circuit in which a plurality of power amplifiers including a signal amplification input circuit and a large current output output circuit are integrated on the same semiconductor substrate.

Conventionally, in this type of known semiconductor integrated circuit for power amplifier circuits, in order to suppress mutual interference between a plurality of power amplifiers, power is supplied independently to circuit elements constituting each amplifier. A separate ground terminal was also provided in order to suppress interference caused by the conductor resistance of the terminal or the bonding wire for connecting the bonding pad and the terminal, which occurs when manufacturing a monolithic power amplifier circuit.

Furthermore, in manufacturing one monolithic power amplifier,
By making the ground wiring or ground terminal of the high gain amplification stage including the input circuit and the output stage that outputs large current a common part, this ground terminal becomes part of the output current path, and the conductor resistance of the bonding wire or terminal is reduced. There is a drawback that a voltage drop occurs in the input stage, and a voltage difference based on this voltage drop is fed back to the input stage, resulting in distortion of the output signal with respect to the input signal.

In order to prevent this drawback, the ground potentials of the output circuit and other circuits are supplied from separate ground terminals, so that the voltage due to the voltage drop in the ground wiring does not return to the preceding circuit.

A conventional semiconductor integrated circuit incorporating two such power amplifiers, for example, has an output circuit section and an input circuit section (other circuits) on one semiconductor substrate 51, as schematically shown in FIG. A power amplifier consisting of an output circuit AB' and an input circuit V is formed, and the input circuits AA and AA' each have an input terminal 52.
An input signal is added from 53, and output circuits AB, AB'
The output signals of are taken out from output terminals 55 and 59, respectively.

Also, the power supply voltage is connected to the input circuit and the output circuit A from the power supply terminal 54.
It is supplied from the power supply terminal 58 to the input circuit V and the output circuit AB'.

On the other hand, the ground potential is set at separately provided ground terminals 57, 56,
61 and 60 are applied to the input circuit side, output circuit AB, input circuit AA', and output circuit section', respectively.

If this capacitor or the like is required, one or two external terminals are provided on the semiconductor substrate 51 for each capacitor.

In this way, conventional monolithic power amplifier circuits require a large number of terminals, especially a large number of ground terminals.This makes the semiconductor substrate and container larger and more complex, making integrated circuit manufacturing complicated and expensive. In addition, the container in which the integrated circuit board is mounted becomes larger and the packaging density becomes lower.

The purpose of this invention is to reduce the number of integrated circuit terminals to a minimum, eliminate voltage feedback due to wiring resistance, and provide a power amplifier circuit for monolithic integrated circuits that is particularly easy to manufacture. .

According to this invention, there are a plurality of power amplifiers (here, two examples will be explained) each consisting of an output circuit such as a class B push-pull circuit and an input circuit such as another signal amplification circuit. In power amplifier circuits integrated on the same semiconductor substrate,
A monolithic power amplification circuit in which the grounding wires of the input circuit of the power amplifier are connected to a first common grounding terminal, and the grounding wires of the output circuit of the power amplifier are further connected to a second common grounding terminal. obtain.

Next, the present invention will be explained in more detail with reference to the drawings.

In one embodiment shown in FIG. 2, the amplifier circuit 1 in the dotted line indicates a monolithic integrated circuit part, and two power amplifiers A,
In B, the components are arranged symmetrically with respect to the center, and the configuration and circuit operation will be described only for one power amplifier, and the same applies to the other.

The semiconductor integrated circuit 1 shown in FIG. 2 is provided with m bonding pads or output terminals, and each of
~3'.

Number them 5' to 6'.

In the embodiment according to FIG. 2, the input signal applied to the terminal 3 is applied through the emitter follower transistor 12 and the DC level shift diode 13 to the base of the transistor 16, and is applied to the base of the transistor 16, which is connected to a differential amplifier constituted by the transistors 16 and 17. It is amplified and output to the collector of the transistor 16, and is also added to the pre-drive transistors 23-24 formed by connecting the transistors 23 and 24 in Darlington, and after being amplified by the pre-drive transistors 23-24, Composite NPN composed of 27.28 transistors
) through a single-ended push-pull circuit consisting of a transistor and a composite PNP transistor composed of transistors 29° and 30, terminal 6 and capacitor Co.
is output to load RL via.

The resistor 11 is a current path for the base current of the transistor 12, and one end is connected to the ground terminal 4, and the differential amplifier 1
One end of the load resistor 18 of 6-17 and the emitter of the predrive transistor 24 are also connected to the ground terminal 4.

A resistor 20 and a diode 21 constitute a voltage source that biases the input circuit. One end of the diode 21 is connected to the ground terminal 4, and the current source 19 passes through the resistor 22 so that the bias voltage at the output terminal 6 is connected to the supply power supply voltage. The diode 26 is a diode for bias determination and temperature compensation.

The output circuit consists of composite NPN transistors 27-28 and composite P
NP) consists of a single-ended push-pull circuit consisting of transistors 29-30, with a final stage transistor 28
and 30 are large current output transistors, and the emitter of the transistor 30 is connected to the ground terminal 7.

A power amplifier A having the above configuration and a power amplifier B similar to the power amplifier B are integrated on the same semiconductor integrated substrate.A two-output (two-channel) power amplifier circuit is constructed as one monolithic integrated circuit.

In the power amplification circuit configured as described above, when an input signal is applied, the signal current flowing through the resistor 11 and the transistor 24 flows to the ground via the ground terminal 4, while the output transistor 28
and 30 are alternately turned on and off, and the signal current flowing from the emitter of the transistor 30 to the ground via the ground terminal 7 is also turned on and off.

The conductor resistance of the bonding pad-bonding line one terminal series corresponding to the integrated circuit has a very small value.

Despite such conductor resistance, the amount of voltage drop varies depending on the magnitude of the path current, and the voltage difference poses a problem.

The signal current flowing through the ground terminal 4 is the signal current of the gain amplification stage including the input circuit, and is generally not very large, and the signal current flows through the grounding pad 4 and the circuit elements connected to the ground line wired to the bonding pad 4. The connection point has almost no voltage difference from the ground voltage.

On the other hand, the signal current flowing through the ground terminal 7 is large and a half-cycle signal voltage component occurs between the emitter of the transistor 30 and the ground voltage.

When this signal voltage difference occurs at the bonding pad 4, it is superimposed on the input signal at the input terminal 3 through the resistor 11, for example, and the output signal output at the output terminal 6 becomes a distorted signal with respect to the input signal. Become.

However, the ground terminal is connected to terminals 4 and 7 as in the above configuration.
By providing it in the above, the above-mentioned disadvantages can be eliminated.

Furthermore, a gain amplification stage including an input circuit of the other power amplifier;
and the ground line of the bias circuit is connected to the bonding pad 4.
The ground line of the output circuit is connected to the bonding pad 7, and the signal current flowing to the ground via the bonding pads 4 and 7 becomes a common current path in each power amplifier. , the voltage difference between the bonding pad 4 and the ground is negligible, and even if the voltage difference between the bonding pad 7 and the ground is applied to the emitters of the output transistors 30 and 30', the bases of these transistors are PNP transistors. Since the current is driven from the collectors of transistors 29 and 29', the output to the collectors of these transistors, that is, the output terminals 6 and 6', is very small, and mutual interference between the power amplifiers is extremely small.

FIG. 3 shows yet another embodiment of this invention, in which the power amplification circuit includes an input circuit BA, and an output circuit BA' output circuit BB.

A power amplifier made of BB' is provided on the same semiconductor substrate 81, and this is attached to the container 71.

The semiconductor substrate 81 is provided with bonding pads 80 to 89 outside the input circuits BA, BA' and the output circuits BB and BB', and the container 71 is provided with terminals 72 to 79 in addition to the semiconductor substrate 81 placed thereon. A bonding line 90 is provided between the bonding pads 80 to 89 and each terminal 72 to 79 (the reference numeral 90 indicates the bonding pad 80).
A bonding wire 90 is connected to the external output terminal 72.
).

Signal input terminal 72.73 and bonding pad 80.8
1 signal output terminal 75.78 and a bonding pad 83.
87, IT source supply terminal 74.77 and bonding pad 82°86, input circuit BA, BA' ground terminal 79 and bonding pad 8B, 89, output circuit BB, BB
The ground terminal 76 and the bonding pads 84 and 85 are connected by a bonding wire 90.

The ground lines of input circuits BA and BA' are connected to the bonding pads 88 and 89, respectively, and
The ground lines B and BB' are connected to bonding pads 84 and 85, respectively.

In such a power amplification circuit, the input circuits BA, BA
Since the ground lines of ' and the ground lines of output circuits BB and BB' are commonly connected by external ground terminals 79 and 76, the signal components generated in the resistance of the bonding wire 90 are mutually connected between the power amplifiers. There is no influence, and the mutual interference between power amplifiers is even less than that in the case where ground lines are connected together on a semiconductor substrate as in the embodiment shown in FIG.

As described above, according to the present invention, only two ground terminals are required even if two power amplifiers are installed, and at this time, there is no voltage feedback due to voltage drop due to wiring resistance.

Furthermore, since the number of ground terminals can be reduced compared to conventional semiconductor integrated circuits, the semiconductor substrate and container can be made smaller and more dense.

Further, since no extra terminals are required, the integrated circuit can be manufactured easily and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional power amplifier circuit, FIG. 2 is a circuit diagram showing one embodiment of this invention, and FIG. 3 is a block diagram showing another embodiment of this invention. 12.12'... Emitter follower transistor, 16, 16', 17, 17'... Differential transistor, 23, 23', 24, 24'... Front position drive transistors, 28.28', 30.30'...
...Output transistor.

Claims (1)

[Claims for Utility Model Registration] ■ The first and second external leads, a signal amplification circuit that amplifies the input signal supplied to the input terminal, and an output circuit that amplifies the power of the output of this signal amplification circuit, respectively. a first power amplifier and a second power amplifier, both of which are formed on one semiconductor substrate;
A first ground line serving as a common ground line for each circuit element forming the signal amplification circuit in the first power amplifier, and a common ground line for each circuit element forming the signal amplification circuit in the second power amplifier. A common ground line for connecting to each of the circuit elements is a second ground line that is formed independently of a part of the first ground line that connects to each of the circuit elements; a third ground line serving as a ground line for the output circuit in the first power amplifier; and a third ground line serving as a ground line for the output circuit in the second power amplifier, and the output circuit in the second power amplifier. The portion connected to the circuit element of the third ground line is formed independently of the portion of the third ground line connected to the circuit element of the output circuit of the first power amplifier, or a fourth ground line is further provided. The first and second ground lines are finally commonly connected to the first external lead, and the third and fourth ground lines are finally common to the second external lead. An integrated circuit device characterized in that it is connected to. 2. The first and second ground lines meet on the semiconductor substrate and are connected to a first bonding pad formed on the semiconductor substrate, and the third and fourth ground lines meet on the semiconductor substrate. The first and second bonding pads are connected to the first and second external leads, respectively. An integrated circuit device according to claim 1, characterized in that: 3. The first to fourth ground lines are respectively connected to first to fourth bonding pads formed on the semiconductor substrate independently of each other, and the first and second bonding pads are connected to the first to fourth bonding pads formed on the semiconductor substrate. The third external lead is connected to the third external lead.
2. The integrated circuit device according to claim 1, wherein the second and third bonding pads are commonly connected to the second external lead. 4. A practical application characterized in that the first power amplifier is separately supplied with an operating voltage through a third external lead, and the second power amplifier is supplied with an operating voltage through a fourth external lead. An integrated circuit device according to claim 1, 2, or 3 of the patent claims.