Radiation-hard ASICs for optical data transmission in the ATLAS pixel detector

TL;DR

This paper presents the development and testing of two radiation-hard ASICs in 0.25 um CMOS technology for optical data transmission in the ATLAS pixel detector, demonstrating their radiation tolerance through irradiation studies.

Contribution

Introduction of two novel radiation-hard ASICs for optical data transmission in high-radiation environments at CERN.

Findings

ASICs successfully implemented in 0.25 um CMOS technology

Prototype circuits operate reliably after irradiation up to 57 Mrad

Radiation hardness achieved through enclosed layout transistors and guard rings

Abstract

We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode for 80 Mbit/s data transmission from the detector, and a Bi-Phase Mark decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode. We have successfully implemented both ASICs in 0.25 um CMOS technology using enclosed layout transistors and guard rings for increased radiation hardness. We present results from prototype circuits and from irradiation studies with 24 GeV protons up to 57 Mrad (1.9 x 10e15 p/cm2).