ST Producing ICs For Atom Smasher
The ALICE group of universities and research institutes is preparing one of the major experiments that will be performed on CERN's Large Hadron Collider (LHC). When built, the LHC is set to be the world's largest atomic particle accelerator. Hadrons are particles that interact through the strong force that binds protons and neutrons in atomic nuclei.
The ALICE (A Large Ion Collider Experiment) experiment is scheduled to start in 2007. ALICE involves high energy collisions between various types of heavy ions and the study of the tens of thousands of resulting particles created by a single collision. The ALICE Collaboration is building a sophisticated detector (the Time Projection Chamber, or TPC) containing nearly 600,000 tiny sensors, each capable of responding to the presence of an individual electron.
The signal from each of these sensors must be amplified, converted to digital format, and then pre-processed by the front-end electronics, which is located deep underground on the TPC. The ALTRO chip integrates 16 low-power analogue-to-digital converters (ADCs), more than 6mn transistors of custom digital processing circuitry and around 800kbits of data memory.
"A critical challenge in designing the Time Projection Chamber was to minimise the size and power consumption of the front-end electronics," reports Dr Jurgen Schukraft, an ALICE spokesperson. "We chose ST as our partner in this project because its existing analogue-to-digital converters offered the lowest power consumption at the conversion speed we needed and its system-on-chip expertise meant that we could integrate all the data conversion, processing, and storage functions for 16 channels on a single chip, greatly reducing the number of circuit boards needed in the TPC."
The ALTRO chip is claimed to have the best dynamic performance/power figure ever reported and has a total power consumption (ADCs, digital processing, and memory) of just 320mW. The TPC detector uses more than 35,000 ALTRO chips.
