Uniform-footprint programmable-skew multi-stage delay cell

Abstract

Described embodiments provide a delay cell for a complementary metal oxide semiconductor integrated circuit. The delay cell includes a delay stage to provide an output signal having a programmable delay. The delay cell has a selectable delay value from a plurality of delay values and a selectable output skew value from a plurality of output skew values, where the cell size and terminal layout of the delay cell are uniform for the plurality of delay values and the plurality of output skew values. The delay stage includes M parallel-coupled inverter stages of stacked PMOS transistors and stacked NMOS transistors. The stacked transistors have configurable source-drain connections between a drain and a source of each transistor, wherein the selectable delay value corresponds to a configuration of the configurable source-drain connections to adjust a delay value of each of the M inverter stages and an output skew value of the delay cell.