Self-Timed Pulsed Latch for Low-Voltage Operation With Reduced Hold Time

Abstract

A self-timed pulsed latch (STPL) is proposed for low $V_{\mathrm {DD}}$ operation. By comparing input and output, the transparency window is adaptively generated in STPL, which resolves the hold time problem of the conventional pulsed latch. The measurement results from the test chip fabricated in the 65-nm technology proves that the hold time is reduced by 77% and the minimum operating supply voltage is lowered by 300 mV compared with the conventional pulsed latch. In addition, the measurement results show that the STPL can reduce the sequential overhead, because the STPL is free from setup time issue from which the conventional master–slave-based flip-flop (MSFF) suffers. The simulation results show that the input-to-output delay of STPL, which also determines the sequential overhead, is smaller by 45% in 0.6 V compared with that of the MSFF structure.