The front-end electronics of Ionization chambers for radiation protection requires challenging sensitivity in the femtoampere range (some 6000e- per second) and a wide dynamic range going to the microampere. This new mixed analog/digital ASIC was designed in 130nm technology and is currently under tests and characterisation.

 

A technology demonstrator chip in GLOBAL FOUNDRIES 22 nm node (Cf. Picture bellow) established techniques of using thick gate transistors in the critical path to minimize leakage thus enabling the use of such technology nodes for low current measurements [1]. 

 

 

By following a similar approach, another ASIC in TSMC 130 nm was designed to compare different current measurement topologies and successfully demonstrated a measurement range from -1 fA to -1 uA [2]. The newest version of the ASIC is also designed in 130 nm technology and incorporates  two current measurement topologies that could attain an ultra-wide dynamic range.

 

 

Current work is currently on going to integrate Accurate into CROME. The first demonstrator is expected for beginning of 2023

 

[1] S. K. Mohanan, H. Boukabache, D. Perrin and U. Pfeiffer, "Femtoampere sensitive current measurement ASIC in 22 nm technology," 2019 IEEE SOI-3D-Subthreshold Microelectronics Technology Unified Conference (S3S), 2019, pp. 1-3, doi: 10.1109/S3S46989.2019.9320710.

[2] S. K. Mohanan, H. Boukabache, D. Perrin and U. Pfeiffer, "Comparative analysis of ultra-low current measurement topologies with implementation in 130 nm technology," in IEEE Access, doi: 10.1109/ACCESS.2021.3074464.