Differential amplification device
Provided is a differential amplification device reduced in DC offset voltage. The amplification device amplifies an input signal, and includes a chopper switch circuit which switches the polarity of the input signal between a normal phase and a reverse phase and outputs the input signal, a V-I conversion circuit which is connected to the chopper switch circuit, a capacitance circuit which is connected to the V-I conversion circuit to store electric charges supplied from the V-I conversion circuit, and an amplification circuit which is connected to the V-I conversion circuit to switch the polarity of an input signal between the normal phase and the reverse phase and amplify the input signal.
1. A differential amplification device, comprising:
a chopper switch circuit configured to switch a polarity of an input signal between a normal phase and a reverse phase;
a V-I conversion circuit configured to convert an output voltage of the chopper switch circuit into a current;
a capacitance circuit directly connected to an output of the V-I conversion circuit; and
an amplification circuit directly connected to the output of the V-I conversion circuit, and configured to switch a polarity of an input signal between the normal phase and the reverse phase.
2. A differential amplification device according to claim 1 ,
wherein the capacitance circuit includes a terminal 1 , a terminal 2 , a terminal 3 , a switch 1 , a switch 2 , a switch 3 A, a switch 3 B, a switch 4 A, a switch 4 B, a capacitor 1 , a capacitor 2 , a capacitor 3 , and a capacitor 4 ,
wherein the terminal 1 is connected to a first terminal of the switch 1 ,
wherein the switch 1 includes a second terminal connected to a first terminal of the switch 3 A, to a first terminal of the switch 4 A, and to a first terminal of the capacitor 1 ,
wherein the switch 3 A includes a second terminal connected to a second terminal of the switch 4 B and to a first terminal of the capacitor 2 ,
wherein the switch 4 A includes a second terminal connected to a second terminal of the switch 3 B and to a first terminal of the capacitor 3 ,
wherein the terminal 2 is connected to a first terminal of the switch 2 ,
wherein the switch 2 includes a second terminal connected to a first terminal of the switch 3 B, to a first terminal of the switch 4 B, and to a first terminal of the capacitor 4 ,
wherein the terminal 3 is connected to a second terminal of the capacitor 1 , to a second terminal of the capacitor 2 , to a second terminal of the capacitor 3 , and to a second terminal of the capacitor 4 ,
wherein on/off operation of the switch 1 and on/off operation of the switch 2 are opposite to each other, and
wherein on/off operation of the switch 3 A and the switch 3 B and on/off operation of the switch 4 A and switch 4 B are opposite to each other.
3. A differential amplification device according to claim 1 , wherein the capacitance circuit is inserted between an input of the amplification circuit and an output of the amplification circuit.
4. A differential amplification device according to claim 2 , wherein the capacitance circuit is inserted between an input of the amplification circuit and an output of the amplification circuit.
5. A differential amplification device according to claim 1 , wherein the capacitance circuit includes a plurality of capacitance circuits.
6. A differential amplification device according to claim 2 , wherein the capacitance circuit includes a plurality of capacitance circuits.
7. A differential amplification device according to claim 3 , wherein the capacitance circuit includes a plurality of capacitance circuits.
8. A differential amplification device, comprising:
a chopper switch circuit configured to switch a polarity of an input signal between a normal phase and a reverse phase;
a V-I conversion circuit configured to convert an output voltage of the chopper switch circuit into a current;
a capacitance circuit connected to an output of the V-I conversion circuit; and
an amplification circuit connected to the output of the V-I conversion circuit, and configured to switch a polarity of an input signal between the normal phase and the reverse phase;
wherein the capacitance circuit includes a terminal 1 , a terminal 2 , a terminal 3 , a switch 1 , a switch 2 , a switch 3 A, a switch 3 B, a switch 4 A, a switch 4 B, a capacitor 1 , a capacitor 2 , a capacitor 3 , and a capacitor 4 ,
wherein the terminal 1 is connected to a first terminal of the switch 1 ,
wherein the switch 1 includes a second terminal connected to a first terminal of the switch 3 A, to a first terminal of the switch 4 A, and to a first terminal of the capacitor 1 ,
wherein the switch 3 A includes a second terminal connected to a second terminal of the switch 4 B and to a first terminal of the capacitor 2 ,
wherein the switch 4 A includes a second terminal connected to a second terminal of the switch 3 B and to a first terminal of the capacitor 3 ,
wherein the terminal 2 is connected to a first terminal of the switch 2 ,
wherein the switch 2 includes a second terminal connected to a first terminal of the switch 3 B, to a first terminal of the switch 4 B, and to a first terminal of the capacitor 4 ,
wherein the terminal 3 is connected to a second terminal of the capacitor 1 , to a second terminal of the capacitor 2 , to a second terminal of the capacitor 3 , and to a second terminal of the capacitor 4 ,
wherein on/off operation of the switch 1 and on/off operation of the switch 2 are opposite to each other, and
wherein on/off operation of the switch 3 A and the switch 3 B and on/off operation of the switch 4 A and switch 4 B are opposite to each other.
9. The differential amplification device according to claim 8 , wherein the capacitance circuit is inserted between an input of the amplification circuit and an output of the amplification circuit.
10. The differential amplification device according to claim 8 , wherein the capacitance circuit includes a plurality of capacitance circuits.