Signal generation circuit and light detecting unit
A signal generation circuit according to one embodiment of the present disclosure includes: an amplifier including a first input section, a second input section, and an output section; a first electric current source that makes it possible to supply an electric current on the basis of an output voltage of the output section; a first capacitor element configured to hold a voltage; a first switch configured to electrically couple the first electric current source and the first capacitor element to each other; a second switch configured to electrically couple the first capacitor element and the first input section to each other; a second capacitor element configured to hold a voltage; a third switch configured to electrically couple the first electric current source and the second capacitor element to each other; and a fourth switch configured to electrically couple the second capacitor element and the first input section to each other.
1 . A signal generation circuit comprising:
an amplifier including a first input section, a second input section, and an output section;
a first electric current source configured to supply an electric current on a basis of an output voltage of the output section;
a first capacitor element configured to hold a voltage;
a first switch configured to electrically couple the first electric current source and the first capacitor element to each other;
a second switch configured to electrically couple the first capacitor element and the first input section to each other;
a second capacitor element configured to hold a voltage;
a third switch configured to electrically couple the first electric current source and the second capacitor element to each other; and
a fourth switch configured to electrically couple the second capacitor element and the first input section to each other.
2 . The signal generation circuit according to claim 1 , further comprising:
a second electric current source configured to supply an electric current on a basis of the output voltage of the output section.
3 . The signal generation circuit according to claim 2 , further including:
a signal output section configured to output a first signal that is based on the electric current supplied by the second electric current source.
4 . The signal generation circuit according to claim 3 , wherein
the signal output section comprises an integrating circuit configured to generate the first signal of which a voltage changes, on a basis of the electric current supplied by the second electric current source.
5 . The signal generation circuit according to claim 1 , wherein
the first capacitor element includes a first electrode electrically coupled to the first switch and the second switch, and
the first capacitor element includes a second electrode electrically coupled to a reference potential line.
6 . The signal generation circuit according to claim 5 , wherein
the second capacitor element includes a first electrode electrically coupled to the third switch and the fourth switch, and
the second capacitor element includes a second electrode electrically coupled to the reference potential line.
7 . The signal generation circuit according to claim 6 , further comprising:
a fifth switch configured to electrically couple the first electrode of the first capacitor element and the reference potential line to each other.
8 . The signal generation circuit according to claim 7 , further comprising:
a sixth switch configured to electrically couple the first electrode of the second capacitor element and the reference potential line to each other.
9 . The signal generation circuit according to claim 1 , further comprising:
a third capacitor element electrically coupled between the first input section and a reference potential line, and configured to hold a voltage.
10 . The signal generation circuit according to claim 9 , wherein
the amplifier is configured to output a voltage that is based on the voltage at the third capacitor element inputted into the first input section and a reference voltage inputted into the second input section.
11 . The signal generation circuit according to claim 1 , further comprising:
a controller configured to control the first switch and the second switch on a basis of a clock signal.
12 . The signal generation circuit according to claim 11 , wherein
the controller is configured to alternately turn the first switch and the second switch into an ON state.
13 . A light detecting unit comprising:
a light receiving element configured to receive light and generate a charge;
a signal generation circuit configured to generate a first signal of which voltage changes; and
a converter that converts a second signal that is based on the charge generated in the light receiving element, into a digital signal on a basis of the first signal, wherein
the signal generation circuit includes:
an amplifier including a first input section, a second input section, and an output section;
a first electric current source configured to supply an electric current on a basis of an output voltage of the output section;
a first capacitor element configured to hold a voltage;
a first switch configured to electrically couple the first electric current source and the first capacitor element to each other;
a second switch configured to electrically couple the first capacitor element and the first input section to each other;
a second capacitor element configured to hold a voltage;
a third switch configured to electrically couple the first electric current source and the second capacitor element to each other;
a fourth switch configured to electrically couple the second capacitor element and the first input section to each other;
a second electric current source configured to supply an electric current on a basis of the output voltage of the output section; and
a signal output section configured to output the first signal that is based on the electric current supplied by the second electric current source.
14 . The light detecting unit according to claim 13 , wherein
the signal output section comprises an integrating circuit configured to generate the first signal of which a voltage changes, on a basis of the electric current supplied by the second electric current source.