Amplifier offset offset improvement method and amplifier employing the same

摘要

A method of improving an input offset in an amplifier to amplify a small signal and an amplifier to which it is applied provide an amplifier that prevents the current consumption and the circuit scale from becoming large and improves the input offset. An amplifier with improved input offset is an amplifier circuit having a first input terminal to which an input signal is applied and a second input terminal to which a reference voltage is applied, an up-down counter and a corresponding analog value corresponding to the count value of the up-down counter The D / a converter is converted to the reference voltage. In addition, an offset comparator for comparing the reference voltage of the amplifier circuit with the output voltage, and outputting the difference signal, and an up-down signal for generating an incremental signal for controlling the increment of the up-down counter based on the output of the offset comparator The ROM control section has a TA control section and generates a motion signal so as to yield the count value of the up-down counter so that the output of the offset comparison section becomes zero.