Process-Invariant Current Source Design: Methodology and Examples

In this paper, we present a design methodology and resulting circuits that compensate for process variations without the need for post-fabrication efforts. We demonstrate how, using this methodology, current sources have been designed with more than a factor of two reduction in normalized standard deviation over equivalent uncompensated current sources. To the best of our knowledge, these are the first measured results showing effective circuit design techniques that reduce the impact of process variations by such magnitude. Such circuits can be an effective way to improve circuit yield as process variations increase.