Abstract: A comparator using an operational amplifier, includes an input switching circuit for passing an input signal in a first state wherein a comparison is effected and for stopping the input signal in a second state wherein an input offset voltage is cancelled. An output switching circuit holds an output signal in the first state and outputs a held output signal in the second state of the input switching circuit. An input/output switching signal generation circuit generates control signals to switch between the first state and the second states; and a first comparator outputs resultant comparison data in the first state and cancels the input offset voltage in the second state.

Abstract: This invention is related to an integrated circuit (IC) having a fuse circuit. In such an IC device, it is very difficult to hold a specific gain of the IC because of a leakage of a gap between the fuse terminals called "re-glown fuse" or "glown-back fuse", and the IC suffers from malfunction. The present invention provides a fuse circuit to detect whether a fuse has been blown or not, by judging whether the fuse resistance is larger or smaller compared to a predetermined threshold resistor, which generates a judging potential corresponding to a fuse condition. Thus the IC can be used without malfunction.