Power distribution with custom DC-DC converters for SLHC trackers

Abstract

The upgrade of the LHC experiments at CERN brings new challenges in the design and integration of the detectors. Among them and to achieve the required channel density, the power distribution to the front-end electronics of the trackers has to be implemented in a more efficient and compact manner. This paper proposes a new powering scheme for the trackers based on the use of custom on-board DC-DC converters. The converters are designed to tolerate high levels of radiation and intense magnetic fields present in the experiments.

Optimization of DC-DC Converters for Improved Electromagnetic Compatibility With High Energy Physics Front-End Electronics

“…Each sinusoidal signal of frequency is said to be the harmonic signal of order n; the harmonic of frequency is said to be the fundamental. The amplitude of the n-th harmonic of is equal to as shown in (2). Similarly, the magnitude of the n-th harmonic of is equal to , as in (3).…”

“…The present powering scheme, based on DC power supplies located in radiation-free areas, approximately 100 meters far from the detectors, can not be used for the HLLHC due to the lack of space for running more power cables and its poor efficiency. One possible solution [1] under study is based on on-detector DC-DC converters [2], which must be radiation [3] and magnetic field [4] tolerant. Furthermore, the converters must be as small as possible and must emit the lowest electromagnetic (EM) noise in order to power the sensitive FEE without perturbing their performance.…”

“…Due to the size constrain, the air-core inductor value can not exceed 500 nH. Therefore, for nominal input and output voltages of 10 V and 2.5 V respectively, the converter switching frequency must be of the order of few (1)(2)(3)(4) MHz for reducing the inductor current ripple to an acceptable value of 1-4 A (1). These constrains limit the noise reduction strategies.…”

DC-DC converters in 0.35μm CMOS technology

“…A solution based on DC-DC converters has been presented in [1]. Point-of-load DC/DC converters, located close to the Front End (FE) electronics, convert the 10-12V present in the supply cables to the 1.2V or 2.5V required by FE chips.…”

An 8W-2MHz buck converter with adaptive dead time tolerant to radiation and high magnetic field

“…The objective of this project is to provide a means to bring power to the frontend electronics with a minimum of copper and with high efficiency. As proposed in [1] and [2], an attractive power distribution scheme satisfying the new requirements is based on the use of buck DC-DC converters installed on-detector very close to the front-end readout electronics (the load). The converters would provide 1-3 A at a voltage of 3.3-1.8 V from a bus voltage of 10-12 V. A simplified scheme of this topology is shown in Figure 1.…”