A digitally controlled linear regulator for per-core wide-range DVFS of atom™ cores in 14nm tri-gate CMOS featuring non-linear control, adaptive gain and code roaming

A digitally controlled LDO in 14nm tri-gate CMOS powering an Atom™ core with embedded power gates enables per-core DVFS over a wide voltage-frequency range. The LDO demonstrates 99.6% peak current efficiency at 2.5A load current and provides a power density of 26.1 W/mm
²
. The multi-mode digital controller featuring non-linear mode and adaptive gain achieves <;20ns settling time with a 100mV droop for a 1.2A load step. A code roaming algorithm complements the feedback controller to successfully mitigate reliability issues from power gate transistor self-heating and electromigration.