A 28 nm Bulk-CMOS Analog Front-End for High-Rate ATLAS Muon Drift-Tube Detectors.

Alessandra Pipino,Luca Mangiagalli,Andrea Baschirotto,Federica Resta,Oliver Kortner,Robert Richter,Hubert Kroha,Marcello De Matteis

doi:10.3390/s20010042

Alessandra Pipino, Luca Mangiagalli + Show 6 more

Open Access

https://doi.org/10.3390/s20010042

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Abstract

This paper presents the design and experimental characterization of a 28 nm Complementary Metal Oxide Semiconductor (CMOS) Analog Front-End (AFE) for fast-tracking small-diameter Muon Drift-Tube (sMDT) detectors. The device exploits an innovative analog signal processing that allows a strong increase in the detection rate of events and significantly reduces the impact of fake/pile-up events, which often corrupt incident radiation energy events. The proposed device converts the input charge coming from incident radiations into voltage by a dedicated Charge-Sensitive Preamplifier (CSPreamp). Therefore, the fast-tracking concept relies on sampling the slope of the CSPreamp output voltage and using it for detecting both the incident event arrival instant and the amount of charge that has been effectively read out by MDT detectors. This avoids the long processing times intrinsically needed for baseline recovery transient, during which the detected signal can be severely corrupted by additional and unwanted extra-events, resulting in extra-charge (and thus in CSP output voltage extra-transient) during the signal roll-off. The proposed analog channel operates with a 5–100 fC input charge range and has a maximum dead-time of 200 ns (against the 545 ns of the state-of-the-art). It occupies 0.03 mm2 and consumes 1.9 mW from 1 V of supply voltage.

Highlights

Periodic upgrades of the Large Hadron Collider (LHC) to discover novel physics constantly generate new technological challenges
The ASD returns two important time-domain data for each event: the charge arrival time and the amount of charge by Time-over-Threshold (ToT) encoding. This is a robust and reliable solution for small-diameter Muon Drift-Tube (MDT) detectors, whereas it scarcely complies with Phase-II upgrades speed requirements, for several reasons, among them:
In order to limit the amount of threshold crossing generated by spurious pulses (SSPs), the read-out electronics adopt different strategies: CSPreamp small time constants, bipolar shaping and the dead-time status after every event detection to neglect the following peaks 4

Summary

Introduction

Periodic upgrades of the Large Hadron Collider (LHC) to discover novel physics constantly generate new technological challenges. The ASD returns two important time-domain data for each event: the charge arrival time and the amount of charge by Time-over-Threshold (ToT) encoding This is a robust and reliable solution for small-diameter MDT (sMDT) detectors, whereas it scarcely complies with Phase-II upgrades speed requirements, for several reasons, among them:. In order to limit the amount of threshold crossing generated by SSPs, the read-out electronics adopt different strategies: CSPreamp small time constants (large bandwidth), bipolar shaping and the dead-time status after every event detection to neglect the following peaks 4 This avoids a pile-up of spurious signals on the first pulse, which is usually the interesting one.

Fast-Tracking

Shaper

Comparators

Experimental Results

State-of-the-art

Conclusions