Deep trench capacitor based step-up and step-down DC/DC converters in 32nm SOI with opportunistic current borrowing and fast DVFS capabilities

Abstract

A switched capacitor step-down converter fabricated in 32nm CMOS achieves a 5X improvement in response time for fast dynamic voltage and frequency scaling (DVFS). We also present a step-up converter based on a bi-directional voltage doubler, which is capable of reducing supply noise up to 45% by opportunistically borrowing current from adjacent idle power domains. Using ultra-high density deep trench capacitors, we are able to achieve an output power density of 2.78W/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at a peak efficiency of 85% from the step-down converter and 0.9W/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at a peak efficiency of 82% from the voltage doubler.