Control device using GaN semiconductor

1. A control device comprising:

a differential amplification circuit that amplifies a difference with respect to an input signal;

a level shift circuit that is connected to an output side of the differential amplification circuit; and

a clipping circuit that is connected to an output side of the level shift circuit and that clips an input voltage,

wherein the differential amplification circuit includes a plurality of switching elements formed of a GaN semiconductor, and

the clipping circuit includes a switching element that:

is formed of the GaN semiconductor,

limits a voltage on a high-level side to a limit voltage that is lower than an upper limit voltage input to the clipping circuit, and

limits a voltage on a low-level side to a limit voltage that is higher than a lower limit voltage input to the clipping circuit.

2. The control device according to claim 1 , further comprising:

an amplification circuit that is connected to the output side of the differential amplification circuit and amplifies a voltage difference of voltages output from the differential amplification circuit, wherein

the level shift circuit is connected to an output side of the amplification circuit, and

the amplification circuit includes a switching element formed of the GaN semiconductor.

3. The control device according to claim 1 , wherein the level shift circuit:

shifts a level of a voltage output from the differential amplification circuit, and

includes a switching element formed of the GaN semiconductor.

4. The control device according to claim 1 , further comprising:

a voltage variable circuit that is capable of changing a control voltage of the switching element included in the differential amplification circuit, wherein

the differential amplification circuit amplifies the difference between a voltage of the input signal and the control voltage.

5. The control device according to claim 1 , further comprising:

a current source that is connected to the differential amplification circuit, wherein

the current source includes a switching element formed of the GaN semiconductor.

6. The control device according to claim 1 , further comprising:

a current source that is commonly connected to each terminal of the plurality of switching elements included in the differential amplification circuit.

7. The control device according to claim 1 , wherein

the plurality of switching elements included in the differential amplification circuit are symmetrically connected,

the input signal is input to a control terminal of one switching element among the plurality of switching elements,

a reference voltage is input to a control terminal of the other switching element among the plurality of switching elements,

the input signal indicates any one of a high level voltage value and a low level voltage value, and

the voltage value of the reference voltage is set between the high level voltage value and the low level voltage value.

8. A control device comprising:

a differential amplification circuit that amplifies a difference with respect to an input signal;

an amplification circuit that is connected to the output side of the differential amplification circuit and amplifies a voltage difference of voltages output from the differential amplification circuit;

a level shift circuit that is connected to an output side of the amplification circuit; and

a clipping circuit that is connected to an output side of the level shift circuit and that clips an input voltage, wherein

the differential amplification circuit includes a plurality of switching elements formed of a GaN semiconductor,

the clipping circuit includes a switching element that:

is formed of the GaN semiconductor,

limits a voltage on a high-level side to a limit voltage that is lower than an upper limit voltage input to the clipping circuit, and

limits a voltage on a low-level side to a limit voltage that is higher than a lower limit voltage input to the clipping circuit, and

the amplification circuit includes a switching element formed of the GaN semiconductor.

9. A control device comprising:

a differential amplification circuit that amplifies a difference with respect to an input signal;

a level shift circuit that is connected to an output side of the differential amplification circuit; and

a clipping circuit that is connected to an output side of the level shift circuit and that clips an input voltage, wherein

the differential amplification circuit includes a plurality of switching elements formed of a GaN semiconductor,

the clipping circuit includes a switching element that:

is formed of the GaN semiconductor,

limits a voltage on a high-level side to a limit voltage that is lower than an upper limit voltage input to the clipping circuit, and

limits a voltage on a low-level side to a limit voltage that is higher than a lower limit voltage input to the clipping circuit,

the plurality of switching elements included in the differential amplification circuit are symmetrically connected,

the input signal is input to a control terminal of one switching element among the plurality of switching elements,

a reference voltage is input to a control terminal of the other switching element among the plurality of switching elements,

the input signal indicates any one of a high level voltage value and a low level voltage value, and

the voltage value of the reference voltage is set between the high level voltage value and the low level voltage value.