JPH0231523B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a voltage amplification circuit configured in a semiconductor integrated circuit comprising complementary insulated gate field effect transistors, and particularly relates to a chopper type voltage amplification circuit. .

[Conventional technology]

Conventionally, there is a chopper type voltage amplifying circuit of this type as shown in FIG. In the figure, 1 and 2 are the respective input terminals, 3 is the output terminal, 4,
5 and 6 are switches each composed of an insulated gate field effect transistor (hereinafter abbreviated as MOS-FET), 7 is an input capacitor, and 8 is a complementary type.
It is an inverting amplifier composed of MOS-FET,
A switch 6 is inserted between the input terminal and output terminal of the inverting amplifier 8, and operates in conjunction with the operation of the switches 4 and 5. Here, if the inverting amplifier 8 is configured with a complementary MOS-FET circuit, the input/output characteristics will generally be a graph as shown in Figure 3, and the current consumption will be expressed as the input voltage and output voltage as shown in Figure 4. It reaches a maximum when the voltages are equal to each other, and almost no flow occurs when the input voltage approaches the ground potential or power supply potential.

However, in order to perform amplification with the chopper type voltage amplification circuit shown in FIG. A timing occurs when the input voltage of the inverting amplifier 8 becomes equal to the output voltage, and a large current consumption flows. Furthermore, when no amplification is performed, leakage current flows to capacitor 7 no matter how switches 4, 5, and 6 are operated, so it is impossible to stably maintain the input voltage of inverting amplifier 8 at ground potential or power supply potential. This will result in large current consumption.

[Problems to be Solved by the Invention] As described above, the conventional circuit cannot stably maintain the input voltage of the inverting amplifier 8 at the ground potential or power supply potential, and therefore consumes a large amount of current even when no amplification is performed. The problem was that it flowed.

The present invention has been made to eliminate the above-mentioned drawbacks of the conventional art, and its purpose is to provide a voltage amplification circuit that can significantly reduce current consumption with a simple configuration.

[Means for solving problems]

The voltage amplification circuit according to the present invention conducts the current-carrying path between the input terminal of the inverting amplifier composed of complementary MOS-FETs constituting the chopper voltage amplification circuit and either the ground potential or the power supply potential. A switch circuit that can be cut off is provided, and this switch circuit is cut off when amplification is performed (during amplification), and made conductive when amplification is not performed (during non-amplification).

[Effect]

In the present invention, since the input voltage of the inverting amplifier can be stably maintained at the ground potential or power supply potential when no amplification is performed, current consumption can be significantly reduced.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a block diagram of a chopper type voltage amplification circuit according to an embodiment of the present invention. Here, the difference from FIG. 2 is that the input terminal of the inverting amplifier 8 and the ground potential 1
Switch 9 composed of MOS-FET between
is provided as a circuit element, and the input voltage of the inverting amplifier 8 is maintained at the ground potential by turning off the switch 9 during amplification and making it conductive when not amplifying. In FIG. 1, the same parts as in FIG. 2 are given the same reference numerals.

According to the chopper type voltage amplification circuit configured in the above embodiment, when amplification is performed, switch 9 is always cut off, and switches 4, 5, and 6 are operated at the timing shown in FIG. 5, as in the conventional circuit described above. Continuity and interruption. Therefore, the operation at this time is no different from the conventional circuit. Next, when amplification is not performed, one or both of switches 4 and 5 are cut off, switch 6 is also cut off, and switch 9 is made conductive. In this state, the output of the inverting amplifier 8 is not connected to anything and the input voltage is completely equal to ground potential. Therefore, as is clear from the graph of FIG. 4, the current consumption of the inverting amplifier 8 is almost negligible, and there is no path in any of the circuits through which direct current flows between the power supply potential and the ground potential. That is, in the amplifier circuit of this embodiment, almost no current consumption can be made to flow when no amplification is performed.

In the above embodiment, the switch 9 is provided between the switch 9 and the ground potential 10, but the same effect can be obtained even if the switch 9 is provided between the switch 9 and the power supply potential. Also, switches 4 and 5
And a plurality of capacitors corresponding to the capacitor 7 may be connected.

〔Effect of the invention〕

As described above, according to the voltage amplification circuit of the present invention, the current consumption when no amplification is performed can be made extremely small, so that it can be incorporated into a semiconductor integrated circuit of a system that does not require constant amplification. In this case, the current consumption of the entire system can be reduced, the lifespan of the system can be extended, and the performance can be improved, especially when operated on batteries.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a chopper type voltage amplification circuit according to an embodiment of the present invention, Fig. 2 is a block diagram of a chopper type voltage amplification circuit showing a conventional example, and Fig. 3 is a complementary type voltage amplification circuit.
An input/output characteristic diagram of an inverting amplifier composed of MOS-FETs. Figure 4 is a diagram showing the relationship between its input voltage and current consumption. Figure 5 is a diagram showing the relationship between the input voltage and current consumption of the inverting amplifier configured with MOS-FETs. FIG. 1, 2...Input terminal, 3...Output terminal, 4,
5, 6...Switch, 7...Capacitor, 8...
Inverting amplifier, 9...switch.

Claims (1)

[Claims] 1. In a semiconductor integrated circuit composed of complementary insulated gate field effect transistors, between the input terminal of an inverting amplifier constituting a chopper voltage amplifier circuit and either ground potential or power supply potential,
1. A voltage amplification circuit characterized by comprising a switch circuit that operates to cut off during amplification and to conduct when not amplified.