Torino Radiotherapy Group
VLSI chip
Precise measurement of intense beam is becoming important in several fields of application and the techniques used to achieve such measurements are based on different detectors. In general to obtain a good spatial resolution the detectors are made of a large number of pixels or strips. Consequently the continuous sampling of any detector requires a front-end with many input channels. In this spirit our group, at the INFN - Torino Division and University of Torino, developed an Application Specific Integrated Circuit (ASIC) to independently read-out the current from up to pixels or strips and convert it to frequency. The conversion is based on the recycling integrator principle, while the integration and the circuitry overall architecture has been studied by our group.
The work has been partially supported by the European Integrated Project MAESTRO, which is granted by the European Commission (“Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology”, No. LSHC-CT-2004-503564, 1 May 2004 - 30 April 2009).
Developed chips
Several version of the ASIC have been already designed and used since 1996. Here is a list of the versions and their features:
- Tera 1.0
- A CMOS 1.2 um technology test chip with 14 channels, asynchronous logic and 20 bits output.
- Tera 2.0
- The complete 64 channel ASIC redesigned in CMOS 0.8 um technology with 20 bits output.
- Tera 3.0
- Same as 2.0, apart from the 16 bits output. It has been used for the equipment of the Magic Cube detector, used for beam calibration.
- Tera 4.0
- Redesign of the 3.0 with clocked comparator and logic in order to obtain an higher resolution.
- Tera 5.0
- Bug corrected version of 4.0. It is used for the equipment of strip gas detector used for CATANA Beam Monitor System.
- Tera 6.0
- Mass production of the 5.0. It is used for the equipment of the pixel and strip gas detector, used for CPO and CNAO Beam Monitor System.
- Tera 7.0
- Redesign in CMOS 0.35 um technology with bipolar input capability, higher speed and better resolution, used for CNAO Beam Monitor System.
In the environment of the EU collaboration Project MAESTRO, the Tera 6.0 chip is used by Scanditronix-Wellhöfer (IBA Group) to equipage commercial dosimeters used in Radiotherapy (I'mRT MatriXX and StarTrack)