Data encoding efficiency in pixel detector readout with charge information

TL;DR

This paper calculates the minimal bits needed for lossless pixel detector readout in particle physics, compares encoding efficiencies, and evaluates the FE-I4 chip's performance against theoretical limits.

Contribution

It introduces a systematic method to assess encoding efficiency and compares real hardware implementation with theoretical minimums.

Findings

Theoretical minimum bits for lossless readout are established.

FE-I4 chip's encoding efficiency is evaluated against optimal limits.

The analysis aids in designing more efficient pixel detector readout systems.

Abstract

The average minimum number of bits needed for lossless readout of a pixel detector is calculated, in the regime of interest for particle physics where only a small fraction of pixels have a non-zero value per frame. This permits a systematic comparison of the readout efficiency of different encoding imple- mentations. The calculation is compared to the number of bits used by the FE-I4 pixel readout chip of the ATLAS experiment.