Uniform-footprint programmable 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 through the delay cell. The delay cell has a selectable delay value from a plurality of delay values, where the cell size and terminal layout of the delay cell are relatively uniform for the plurality of delay values. The delay stage includes M parallel-coupled inverter stages. Each parallel-coupled inverter stage includes N pairs of stacked PMOS transistors and stacked NMOS transistors. The N transistor pairs have configurable source-drain node connections between a drain node and a source node of each transistor in the pair, wherein the selectable delay value corresponds to a configuration of the configurable source-drain node connections to adjust a delay value of each of the M inverter stages.