Switched capacitor DC-DC converter ASICs for the upgraded LHC trackers

M Bochenek,S Michelis,F Faccio,W Dabrowski

doi:10.1088/1748-0221/5/12/c12031

Abstract

The High Luminosity Upgrade of the ATLAS Inner Tracker puts demanding requirements on the powering system of the silicon strip detector modules due to 10-fold increase of the channel count compared to the existing SemiConductor Tracker. Therefore, new solutions for the powering scheme must be elaborated. Currently two possible approaches, the serial powering and the parallel powering scheme using the DC-DC conversion technique, are under development. This paper describes two switched capacitor DC-DC converters designed in a 130 nm technology. For the optimized step-down converter, foreseen for the parallel powering scheme, power efficiency of 97% has been achieved, while for the charge pump, designed for the serial powering scheme, power efficiency of 85% has been achieved.

Highlights

The High Luminosity Upgrade of the ATLAS Inner Tracker puts demanding requirements on the powering system of the silicon strip detector modules due to 10-fold increase of the channel count compared to the existing SemiConductor Tracker
The corner analysis performed for the design shows that in the worst case the output voltage will be not less than 918 mV and the power efficiency will be at least 96% for the nominal
The designs of two switched capacitor DC-DC converters, step-down and step-up, have been worked out in a 130 nm CMOS technology. Both designs have been optimized with respect to the power efficiency for the specific requirements driven by two possible schemes of powering detector modules in the ATLAS Upgrade Tracker

Summary

Introduction

The High Luminosity Upgrade of the ATLAS Inner Tracker puts demanding requirements on the powering system of the silicon strip detector modules due to 10-fold increase of the channel count compared to the existing SemiConductor Tracker. A simplified schematic of the switched capacitor step-down converter proposed for the DCDC powering scheme and optimized for the output current of 60 mA is shown in figure 1(a).

Results

Conclusion