A process-insensitive current-controlled delay generator with threshold voltage compensation

A process-insensitive current-controlled delay generator is presented with a large tunable range of the time delay. By adopting process variation compensation techniques in the generation of time delay, the delay generator is able to provide process-insensitive clock pulses. The circuit has been fabricated in 90 nm CMOS technology, consumes 310 μW from a 1.1V supply. Using, in a typical case, 20μA of reference current, it can generate a delay of 2.36 ns. The delay variation observed in 14 measured chips has shown a standard deviation of 1.24%.