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Amplifier

Imported: 25 Feb '17 | Published: 01 Jul '03

Masanori Tachibana

USPTO - Utility Patents

Abstract

An amplifier includes a first voltage follower including P-type MOS transistors and a second voltage follower including N-type MOS transistors. The first voltage follower amplifies without being saturated even if an input signal voltage approaches a level of a power supply voltage when the input signal voltage is at least equal to a bias voltage, but does not amplify when the input voltage is less than the bias voltage. A second voltage follower of the amplifier amplifies without being saturated even if an input signal voltage approaches a ground potential when the input signal voltage is less than the bias voltage, but does not amplify when the input voltage is at least equal to the bias voltage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram that shows a configuration of a first embodiment of an amplifier according to the present invention,

FIG. 2 is a circuit diagram that shows a configuration of a second embodiment of an amplifier according to the present invention,

FIG. 3 is a characteristic diagram that shows an example of an input-output characteristic of the amplifier shown in FIG. 2,

FIG. 4 is a circuit diagram that shows a configuration of a third embodiment of an amplifier according to the present invention,

FIG. 5 is a characteristic diagram that shows an example of an input-output characteristic of the amplifier shown in FIG. 4,

FIG. 6 is a circuit diagram that shows a configuration of a fourth embodiment of an amplifier according to the present invention,

FIG. 7 is a characteristic diagram that shows an example of an input-output characteristic of the amplifier shown in FIG. 6, and

FIG. 8 is a circuit diagram that shows a configuration of an amplifier used in the conventional semiconductor integrated circuit.

Claims

1. An amplifier comprising:

2. The amplifier according to claim 1, further comprising a series circuit connected between ground and an output line common to the first current mirror circuit and the second current mirror circuit, wherein the series circuit includes a load resistor and an output bias voltage source.

3. The amplifier according to claim 2, wherein gain of the amplifier is determined only by a ratio of the resistances of the first and second resistors and resistance of the load resistor.

4. An amplifier comprising:

5. The amplifier according to claim 4, wherein gain of the amplifier is determined only by a ratio of the resistance of the resistor and resistance of the load resistor.

6. An amplifier comprising:

7. The amplifier according to claim 6, wherein gain of the amplifier is determined only by a ratio of the resistance of the resistor and resistance of the load resistor.