A hybrid event-based pixel for low-power image Sensing

Mohamed Akrarai (1) , Nils Margotat (1) , Gilles Sicard (2) , Laurent Fesquet (1)

1 TIMA-CDSI - Circuits, Devices and System Integration
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

This article presents a hybrid pixel dedicated to event-based image sensors, which suppresses spatial and temporal redundancies. This pixel is a combination between two kinds of pixels, known as TFS and DVS. The first one is able to reduce - associated to a dedicated readout - spatial redundancies, while the second manages the temporal redundancies. Each pixel is classically built with a photodiode but this hybrid structure shares the photodiode between the DVS and the TFS pixels. In our design, 4 TFS pixel photodiodes are shared with 1 DVS pixel, which exploits the average current of the latter. In order to evaluate such a pixel, a comparison is made between a hybrid pixel matrix and a matrix composed of TFS and DVS pixels.
The evaluation is made in terms of activity and power but also by analyzing their fill-factor, circuitry and layout. A testchip including the 2 event-based image sensors has been designed in FDSOI 28 nm technology from STMicroelecronics.

Mots clés: dynamic vision sensor pixel; event based techniques; time to first spike pixel

Domaines: Micro et nanotechnologies/Microélectronique

Mohamed Akrarai, Nils Margotat, Gilles Sicard, Laurent Fesquet. A hybrid event-based pixel for low-power image Sensing. 28th IEEE International Conference on Electronics Circuits and Systems (ICECS 2021), Nov 2021, Dubai, United Arab Emirates. ⟨10.1109/ICECS53924.2021.9665509⟩. ⟨hal-03662342⟩