A Digitally Controlled Fully Integrated Voltage Regulator With On-Die Solenoid Inductor With Planar Magnetic Core in 14-nm Tri-Gate CMOS

A fully integrated digitally controlled two-phase buck voltage regulator (VR) with on-die solenoid inductors with a planar magnetic core is demonstrated in 14-nm tri-gate CMOS for fine-grained power delivery/management domains of high power density in system-on-chips while enabling ultra-thin (z-height) packages. The VR achieves 1-A/mm
²
power density for 400-mA load current with a measured peak efficiency of 84% at 100-MHz switching frequency including a digital PWM with >9 bits (8 ps) of resolution.