Amplifier circuit
AssigneeSii Semiconductor Corporation
InventorTsutomu Tomioka
Life of this patent
Estimating the term…
Abstract
Provided is an amplifier circuit including an NMOS transistor having a low drain breakdown voltage and an NMOS transistor having a high drain breakdown voltage connected in series thereto, and capable of preventing breakdown of a drain of the NMOS transistor having a low drain breakdown voltage. A clamp circuit configured to limit a drain voltage of the NMOS transistor having a low drain breakdown voltage is connected to the drain thereof.
Claims14
An amplifier circuit configured to amplify a signal input to an input terminal and to output the amplified signal to an output terminal,
- the amplifier circuit comprising:
- a first transistor including a gate directly connected to the input terminal;
- a second transistor including a drain connected to the output terminal and a source connected to a drain of the first transistor, the second transistor having a drain breakdown voltage higher than a drain breakdown voltage of the first transistor and being always in an operating state;
- and
- a clamp circuit connected between the drain of the first transistor and a power supply, and configured to limit a drain voltage of the first transistor.
An amplifier circuit configured to amplify a signal input to an input terminal and to output the amplified signal to an output terminal,
- the amplifier circuit comprising:
- a first transistor including a gate connected to the input terminal;
- a second transistor including a drain connected to the output terminal and a source connected to a drain of the first transistor, the second transistor having a drain breakdown voltage higher than a drain breakdown voltage of the first transistor and being always in an operating state;
- and
- a clamp circuit connected to the drain of the first transistor, and configured to limit a drain voltage of the first transistor;
- wherein the second transistor comprises a depletion transistor.
An amplifier circuit configured to amplify a signal input to an input terminal and to output the amplified signal to an output terminal,
- the amplifier circuit comprising:
- a first transistor including a gate connected to a constant voltage circuit, a drain connected to the output terminal, and a source connected to a power supply terminal;
- a second transistor including a gate connected to the input terminal, a drain connected to a ground terminal, and a source connected to the output terminal, the second transistor having a drain breakdown voltage higher than a drain breakdown voltage of the first transistor;
- and
- a clamp circuit comprising a transistor including a gate and a source both connected to the drain of the first transistor and a drain connected to the input terminal, the clamp circuit being configured to limit a drain voltage of the first transistor.
Dependencies are inferred from the claim text.