A sequence independent power-on-reset circuit for multi-voltage systems

With the advent of multiple supply domains on a single chip, issues related to power sequencing are becoming a major hurdle for system designers. Existing POR strategies fail to cope up with these issues. We propose a scheme in which the power on reset generation is independent of the sequence of supply ramp-up. The circuit implementation of the proposed methodology has been realized for a dual supply system. The basic circuit is modified so as to consume zero static current. An attempt to reduce any leakage current during supply ramp-up has also been made successfully. Simulation results verify the sequence independence concept and low power consumption. Further the proposed realization is modular enough to be extended for more number of supplies