Now, I am thinking about a circuit that acts a bit like an inductor. It will block ac signal noise from power supply while having no effect on dc operating point. I tried to use inductor but it is too big to be implemented in an IC TSMC 0.18um. Could anyone suggest some topologies to do that?
Other disadvantage of inductor is that at low frequencies, the ac noise is not blocked significantly. At DC (0Hz) the inductor has no effect, it is only good at high frequencies. However, I want to block ac noise even low frequency (from 1Hz to 1Khz).