JPH02131018A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To reduce the power consumption of the entire semiconductor integrated circuit by providing a power pin to a power wire of a reference voltage generating circuit separately and supplying power to the reference voltage generating circuit via other power pin only at a specific time. CONSTITUTION:In the case of activating a specific block 2 such as a test circuit, the same voltage as that to a high voltage side power pin 3 is applied to a high voltage side power pin 9a to activate the block 2 similar to the normal operation circuit block. When the normal operation circuit block 1 is in operation, the same voltage as that to a low voltage side power pin 5 is applied to the high voltage side power pin 9a. In this case, the difference of potential between a wire part 10a of the reference voltage generating circuit 22 and a wire part 6 is lost and the potential goes to a low voltage. Since the bias voltage between the base and emitter of a transistor(TR) Q3 for a constant current source in the specific circuit block 2 is zero, the TR Q3 is always turned off. Thus, the specific circuit block is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit that includes a circuit block that operates normally and a specific circuit block that operates at a specific time.

[Conventional technology]

FIG. 3 is a block diagram of a conventional semiconductor integrated circuit (emitter-coupled logic circuit). In the figure, 1 is a normal operation circuit block that normally operates, 2 is a specific circuit block that is used only at a certain time and is not used during normal operation, 3 is a high voltage side power supply pin, 4 is a high voltage side power supply wiring, and 5 is a low voltage side power supply pin. Voltage side power supply pins, 6 are low voltage side power supply wiring, 7 is a group of input pins connected to each circuit block (not shown), and 8 is a group of output pins connected to each circuit block (not shown).

Further, the specific circuit block 2 includes a reference voltage generating circuit 22, a differential amplifier including resistors R1 to R4, and transistors Q1 to Q4. Note that 19 is the output of the differential amplifier, and 20.21 is the reference potential given to the differential amplifier.

Now, this emitter-coupled logic circuit has high voltage side power supply pin 3. By applying a prescribed voltage to each of the low-voltage side power supply pins 5 and inputting an input signal to the input pin group 7, the normal operation circuit block 1 and the specific circuit block 2 are operated.

[Problem to be solved by the invention]

However, since the conventional semiconductor integrated circuit is configured as described above, power is supplied to a specific circuit block even during normal operation, resulting in an increase in power consumption of the entire semiconductor integrated circuit.

The present invention has been made to solve the above-mentioned drawbacks.
It is an object of the present invention to obtain a semiconductor integrated circuit in which power consumption in a specific circuit block 2 becomes zero during normal operation.

[Means to solve the problem]

In the semiconductor integrated circuit according to the present invention, a separate power supply pin is provided in the power supply wiring of the reference voltage generation circuit.

[Effect]

Power is supplied to the reference voltage generation circuit through a separate power supply pin only at specific times.

〔Example〕

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

FIG. 1 is a circuit diagram of a semiconductor integrated circuit (emitter-coupled logic circuit) showing one embodiment of the present invention.

In the figure, the same parts as in FIG. 3 are given the same reference numerals.

9a is a high voltage side power supply pin that is a separate power supply pin connected to the reference voltage generation circuit 22 of the specific circuit block 2;
0a is a high voltage side power supply wiring connected to a specific circuit block.

Next, the operation of the emitter-coupled logic circuit having the above configuration will be explained. When operating a specific block 2 such as a test circuit built in a semiconductor integrated circuit, a high voltage side power supply bin 9a connected to the reference voltage generation circuit 22 of the specific circuit block 2 is connected to a high voltage side power supply bin 9a. By applying the same voltage as 3, it can be operated in the same way as the normal operation circuit block.

On the other hand, when the specific circuit block 2 is not operated (when the normal circuit operation block 1 is operating), the low voltage side power supply is connected to the high voltage side power supply bin 9a connected to the reference voltage generation circuit 22 of the specific circuit block 2. Apply the same voltage as pin 5. At this time, the wiring section 10a of the reference voltage generation circuit 22
There is no difference in potential between the potential of the wiring portion 6 and the potential of the wiring portion 6, resulting in a low potential. The potentials 20 and 21 of the reference voltage generation circuit 22 also become low potentials. As a result, the base-emitter bias voltage of the power failure current source transistor Q3 in the specific circuit block 2 becomes O, so that the transistor Q3 is always in an off state. Therefore, both switching transistors Ql and Q2 constituting the differential amplifier are also turned off. Further, in the output limiter follower transistor Q4 of the differential amplifier, the base-emitter is in a reverse bias state and is always off, so the potential at the output terminal 22 is a low potential. Therefore, the specific circuit block is in a stopped state.

Furthermore, FIG. 2 is a circuit diagram of a semiconductor integrated circuit (emitter-coupled logic circuit) showing another embodiment of the present invention. In the figure, the same parts as in FIG. 1 are given the same reference numerals. 9b
10b is a high voltage side power supply bin corresponding to a separate power supply pin connected to the specific circuit block 2, and 10b is a high voltage side power supply wiring connected to the specific circuit block.

In FIG. 2, as in FIG. 1, a specific circuit block can be brought into operation or stopped by switching the voltage to the high-voltage side power supply bin 9b.

In this way, all transistors 01 to Q4 of the reference voltage generation circuit 22 in the specific circuit block 2 are turned off, so the power consumption of the specific circuit block 2 becomes zero, and the power consumption of the entire semiconductor integrated circuit can be kept low. can.

〔Effect of the invention〕

As described above, in the present invention, since a separate power supply pin is provided in the power supply wiring of the reference voltage generation circuit, power can be supplied to the reference voltage generation circuit through the separate power supply pin only at specific times. This has the remarkable effect of reducing the power consumption of a specific circuit block to zero when the circuit block that normally operates is in operation, and reducing the power consumption of the entire semiconductor integrated circuit. .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a semiconductor integrated circuit showing one embodiment of the present invention, FIG. 2 is a circuit diagram of a semiconductor integrated circuit showing another embodiment, and FIG. 3 is a circuit diagram of a conventional semiconductor integrated circuit. . 1... Normal operation circuit block, 2... Specific circuit block, 9a, 9b... High voltage side power supply pin, 22...
Reference voltage generation circuit.

Claims (1)

[Claims] A semiconductor integrated circuit comprising a circuit block that operates normally and a specific circuit block provided with a reference voltage generation circuit that operates at a specific time, each circuit block being connected to a power supply pin via a power supply wiring. A semiconductor integrated circuit, wherein a separate power supply pin is provided in the power supply wiring of the reference voltage generation circuit, and power is supplied to the reference voltage generation circuit via the separate power supply pin only at specific times.