Abstract: An AD converter includes: a DA converter; a comparator configured to be capable of resetting a comparison output signal to a first level after a comparison operation is performed based on an output of the DA converter and before a next comparison operation is performed; a level shifter configured to be capable of level-shifting and outputting the comparison output signal such that a change from the first level to a second level is faster than a change from the second level to the first level; a register configured to be capable of obtaining the output of the level shifter; and a logic circuit configured to be capable of controlling the DA converter.

Abstract: The present disclosure provides a current source circuit. The current source circuit includes a constant current circuit and a current supply unit. The constant current circuit includes a first MOS transistor, a second MOS transistor and a first resistor. The first MOS transistor includes a source connectable to an applying end of a fixed voltage, a drain, and a gate that is shorted with the drain. The second MOS transistor includes a threshold voltage (Vth) lower than a threshold voltage of the first MOS transistor, and includes a gate connected to the gate of the first MOS transistor. The first resistor is connected between a source of the second MOS transistor and the source of the first MOS transistor. The current supply unit is configured to supply a current to the gate of the first MOS transistor.