OPERATING AMPLIFIER, IMAGE SENSOR HAVING THE SAME, AND METHOD FOR COMPENSATING FREQUENCY RESPONSE OF THE SAME

摘要

PURPOSE: An operational amplifier circuit, an image sensor including the same, and a method for compensating a frequency response of an operational amplifier are provided to output a high frequency signal by widening a bandwidth and implementing stability by adjusting capacitance according to a feedback gain. CONSTITUTION: An operational amplifier circuit includes a first operational amplifier(10), a second operational amplifier(20), a feedback block(30) and a variable compensation capacitor(Cc). The first operational amplifier differentially amplifies an input signal. A load capacitor and the variable compensation capacitor are connected to an output port of the first operational amplifier. The feedback block adds a feedback gain to the output of the first operational amplifier and then feeds back the result to the input of the first operational amplifier. The capacitance of the variable compensation capacitor varies on the basis of the feedback gain.