A high speed pipelined analog-to-digital converter using modified time-shifted correlated double sampling technique

In this paper, a pipelined analog-to-digital converter (ADC) which employs a modified time-shifted correlated double sampling (CDS) technique is proposed. The conventional time-shifted CDS technique can significantly reduce the errors due to the finite gain of the operational amplifier (op-amp) without compromising the conversion speed. However, it needs a high-linearity op-amp to realize the front-end sample-and-hold (SHA) such that the sampled signal without being distorted too much. In order to relax the high-linearity requirement of the op-amp, a new type of SHA circuit is presented