DC-DC converters with reduced mass for trackers at the HL-LHC

Abstract

The development at CERN of low noise DC-DC converters for the powering of frontend systems enables the implementation of efficient powering schemes for the physics experiments at the HL-LHC. Recent tests made on the ATLAS short strip tracker modules confirm the full electromagnetic compatibility of the DC-DC converter prototypes with front-end detectors. The integration of the converters in the trackers front-ends needs to address also the material budget constraints. The impact of the DC-DC converters onto the material budget of the ATLAS tracker modules is discussed and mass reduction techniques are explored, leading to a compromise between electromagnetic compatibility and mass. Low mass shield implementations and Aluminum core inductors are proposed. Also, the impact on emitted noise due to a size reduction of critical components is discussed. Finally, material reduction techniques are discussed at the board layout and manufacturing levels.

The ATLAS ITk strip detector. Status of R&D

“…The baseline for the strip detector is DC to DC conversion, with off-detector power supplies at a higher voltage, reducing the current on the cables and the ohmic losses [5]. On-detector, buck DC-DC converters lower the voltage to the required by the on-detector electronics.…”

Electrical performance of a silicon micro-strip super-module prototype for the High-Luminosity LHC collider

“…4) is used to supply the digital voltage needed to operate the ABCN-25 ASICs (the analogue voltage for the FE being produced from the on-chip voltage regulator). The SM01C is a low-noise plug-in converter module operating with an input voltage of 10-12 V and providing a regulated 2.5 V with a maximum current of 5 A and a nominal conversion efficiency of $ 80% [9].…”

“…In order to limit the electromagnetic emissions from the power converter, a polyethylene (PE) shielding box with a 10 mm coated copper (Cu) layer is used. The 10 mm Cu coated PE box was measured to provide an effective shielding effectiveness similar to the one obtained with the baseline shield assembly (35 mm copper foil box), resulting in a magnetic field attenuation of $ 32 dB [9].…”

Development of readout system for double-sided silicon strip modules

“…Eight modules will be finally installed with 640 ABCN chips and 16 BCC boards. The digital voltage for the ABCN chips is provided by prototype SM01C DC-DC converters [11]. Three different service buses have been produced and are used in the prototype.…”