| 摘要 |
PROBLEM TO BE SOLVED: To provide a comparator which can enhance precision of a system and can suppress error of an AD converter or image deterioration while reducing noise (error) being given to the power supply thereof, and to provide an AD converter, a solid-state image pickup device, a camera system, and an electronic apparatus.SOLUTION: The comparator includes a first amplifier which outputs a signal of a level corresponding to the comparison result of a reference voltage and an input signal potential from a first output node, a second amplifier which outputs a signal output from the output node of the first amplifier, from a second output node, while increasing the gain, and a level maintaining unit. The second amplifier includes a transistor for amplification connected between the second output node and a power supply or a reference potential, and a transistor for current source connected between the second output node and the reference potential or power supply. The level maintaining unit maintains the level at the second output node of the second amplifier so as not to fall into a level at which the transistor for current source of the second amplifier does not satisfy the saturation operation conditions. |
