Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
PICA chip technical specification General PICA is an integrated circuit that performs all the functions associated with normal pulse spectroscopy and counting instrumentation on a single chip. The PICA chip builds upon the state of the art CHICSi readout chip that for the first time integrates low level and fast digital signal processing on the same chip. Using novel approaches and state of the art integrated circuit processing the PICA chip can perform all the functions of a an entire crate NIM of electronics from preamplifiers to ADC and counters. The chip features two input channels and all the logic pulse processing and counters for: Single channel pulse processing spectroscopy, for EDX microscopy, XRF, RBS, Multiscaling spectroscopy used in ESCA, X-ray diffraction, electrostatic and magnetic sector spectrometers Time of flight spectroscopy used in oil prospecting, security survey instruments for explosives and contraband detection Coincidence spectroscopy used for nuclear imaging, positron spectroscopy, E-E spectroscopy. Time spectroscopy, used for LASAR ranging LIDAR etc. The logic unit allows the chip to be configured for: Operation, in simple single channel handheld instruments or for large numbers of channels encountered needed for read out of large detector arrays encountered for medical imaging and frontline physics research. Control and read out via a standard low-cost and fast USB interface or a standard wireless internet controller. The latter offers the feature of reducing expensive and space-consuming cable connections or for simplifying remote sensing applications. Program control of discriminator levels simplifying set up and diagnostic of detectors. Identification and handling of local and global pile-up High-speed readout by suppressing channels that do not contain data. The use of state-of-the-art mixed mode CMOS processing enables the power consumption to be drastically reduced beyond what is needed for conventional NIM electronics. This gives a major economic advantage in terms of energy costs for read out of large detector arrays and also opens up the possibility of sophisticated instruments for hand held and remote sensing applications. Analogue specifications Number of complete analogue channels Input capacitance range Optimal detector capacitance Input signal range Energy resolution Analogue shaper time constant 2 0 – 500 pF 40 pF 0 – 100 MeV in Si (0 - 4.4 pC) 2 keV fwhm in Si 2 µs (fixed) Analogue energy gains Time to amplitude converters 0 - 4, 0 – 20, and 0 –100 MeV 0-0.5 µs, 0-10 µs Digital signal specifications Discriminators Discriminator shapers time constant Discriminator resolution Counters Pile-up inspection types Time to amplitude converters Time measurements Time resolution Individually set by 10 bit DACs 200 ns, 50 ns 5 keV up to 5 MeV, 100 keV above 2 x 12 bits Local, global 0-0.5 µs, 0-10 µs Ch.1–ch.2, ch1-ch1, ch2-ch2 1 ns Control specifications Operation mode Discriminator levels Pile up control Calibration ADC specifications Resolution Type Channel width for different analogue gains Stability Interface specifications Digital readout buffer memory Readout type Max time to read out entire chip Chip dead time Address scheme Chip parameters Process Number of pins Options Voltage reference Supply voltages Programmable Digitally programmable Programmable Programmable on chip test pulse generator 12 bits Delta Sigma 0-4 MeV: 1 keV, 0-20 MeV: 5 keV, 0100 MeV: 25 keV ~100 ppm/ C 88 bits (6x12 bit ADC conversions +16 digital bits) Synchronous with fast hop over function if chip does not hold valid data Max 2.9 µs on 30 MHz USB2.0 controller bus 12 µs Travelling token with synch pulse Mixed mode CMOS 28 Mounted on header, naked chip UHV compatible chip Band gap reference, <~100 ppm / C +/- 1V separate low and high level analogue and digital