Metastability behavior of mismatched CMOS flip-flops using state diagram analysis

The effect on the metastability of the mismatch of FET parameters and load capacitances in a CMOS latch/flip-flop is analyzed. A novel method using state diagrams is proposed. On the state diagrams obtained by transient analysis of the latch, a straight line can be approximately drawn that defines two semiplanes, which precisely determine the latch final state. SPICE simulation results are shown for matched/mismatched flip-flops.