First measurements on the Timespot1 ASIC: a fast-timing, high-rate pixel-matrix front-end

Abstract

This work presents the first measurements performed on the Timespot1 ASIC. As the second prototype developed for the TimeSPOT project, the ASIC features a 32 × 32 channels hybrid-pixel matrix. Targeted to space-time tracking applications in High Energy Physics experiments, the system aims to achieve a time resolution of 30 ps or better at a maximum event rate of 3 MHz/channel with a data driven interface. Power consumption can be programmed to range between 1.2 W/cm2 and 2.6 W/cm2. The presented results include a description of the ASIC operation and a first characterization of its performance in terms of time resolution.

A silicon vertex detector with timing for the Upgrade II of LHCb

“…Two candidates have been chosen to be the potential predecessor for the VeloPix II used in Upgrade II. The Timespot ASIC offers a time resolution of 30 ps [8], while having a power budget of W/cm 2 . It is designed especially for 3D sensors.…”

4-Dimensional Trackers

“…Dedicated integrated CMOS 28 nm read-out electronics is under development. A small prototype ASIC, named Timespot1, featuring a matrix of 1024 pixels and integrating one TDC per pixel channel has been recently tested being capable of a time resolution around 30 ps on the full read-out chain [59].…”

Electronics for Fast Timing

“…The chip is being fabricated with TSMC's 65nm technology using design principles consistent with radiation hardening and targets the following features: picosecond-level timing resolution; 10 Gs/s waveform digitization rate to allow pulse shape discrimination; moderate data buffering (256 samples/chnl); autonomous chip triggering, readout control, calibration and storage virtualization; on-chip feature extraction and multi-channel data fusion; reduced cost and increased reliability due to embedded controller (reduction of external logic). Existing readout approaches, such as ALTIROC [34] and the newer TimeSPOT1 [35], promise good-to-excellent timing resolution and channel density, and use a TDC-based measurement for signal arrival times and time-over-threshold (ToT) for an indirect estimate of integrated charge. However, these readout strategies will likely adversely impact the ability to provide sub-pixel spatial resolution and typically have difficulty compensating for environmental factors such as pile-up, sensor aging, and radiation; timing precision can also be adversely impacted by factors such as timewalk, baseline wander and waveform shape variations.…”