US Patent 10224906 Semiconductor device

A hysteresis comparator that has a small circuit area and low power consumption is provided. A differential pair in the comparator is formed using transistors each including a back gate. The comparator is configured to apply an inverted signal of a logic value of an output signal of the comparator to the back gate of the transistor. That is, the threshold voltage of the transistor is controlled by the inverted signal. By the change of the threshold voltage, hysteresis can be added to an input comparison voltage.