Download PICA chip technical specification

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:
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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
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Coincidence spectroscopy used for nuclear imaging, positron spectroscopy, E-E
spectroscopy.
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Time spectroscopy, used for LASAR ranging LIDAR etc.
The logic unit allows the chip to be configured for:
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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.
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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.
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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