A review of the MedPix and TimePix is given in \cite{Ballabriga_2018}. TimePix3 features:
- Data-driven architecture
- Threshold variation 30 e- with a minimum threshold 500 e-
- 48-bit word for each pixel hit, 5.2 Gbps output bandwidth, can due with 80 Mhits/s
VeloPix, described in \cite{Poikela_2015}:
- 15 hits in every LHC bunch crossing
- Radiation protection techniques: Triple Redundancy used to mitigate the effects of Single Event Upset
- Validated hits are time-tagged to the 40 MHz LHC clock by latching the content of 9-bit Gray-encoded Bunch Crossing Counter.
- The initial electrical results from the chip indicates that full functionality has been achieved. However, measurements with bump-bonded sensors and radiation tolerance are still underway.
How it works:
- The sensor is gas. In case of veloPix, it's silicon.
- The photo-electrons from the ionizing particles are collected
- Medpix2 simply count the number of hits above the threshold; TimePix has 3 options of measurements: 1) the Time-Over-Threshold; 2) number of hits; 3) Time-Of-Arrival.