operation amplifier and pipelined analog to digital converter using the same

摘要

PURPOSE: An operational amplifier and a pipe line analog digital converter using the same are provided to prevent a signal-dependent error due to a prior input signal by initializing an input terminal which is not operated through a switch. CONSTITUTION: A first channel(460) is formed between a sub input terminal and an output terminal of an operational amplifier. An input selecting unit determines a connection state between the first and second channels and an analog signal input terminal and a reference voltage input terminal. The first input terminal and the second input terminal receive a positive input and a negative input and differentially amplify the received input. A control signal applying unit(490) applies a control signal for controlling the connection state of the first input terminal and the second input terminal. The amplification of the first input terminal, the amplification of the second input terminal, the initialization of the first input terminal, and the initialization of the second input terminal are alternatively executed.