Download At present time the avalanche photodiodes and hybrid

Short description (unrestricted summary) of proposal of ISTC Project.
Yerevan Physics Institute(YerPhI)
At present time the avalanche photodiodes and hybrid photodiodes(HPD) are widely
adopted in the different area of science and technologies, in particular in High Energy
Physics, due to their high sensitivity, small sizes, insensibility to magnetic field etc. But the
fast signal extraction for different aims from mentioned large capacitive detectors and
some other types of capacitive sources of signals has a lot of specific problems. Typically it
is difficult to provide the following qualities to a capacitive detectors simultaneously – fast
rise and fall times (a few nanoseconds), low level of Noise Slope and high gain at high
frequencies.
The task one is - to resolve that problem the design of special bipolar hybrid
transimpedance amplifier(TIA) is suggested which will have a) low input impedance (<10
Ohm)*, b) small noise slope and c) high gainbandwidth product (20-40 mV/mkA at 250
MHz).
The task two is – in addition the design of low current threshold (~1 µA at 100 MHz)
hybrid discriminator is suggested.
The task three is - to incorporate above mentioned circuits with HPD photodetectors
by thin film hybrid technology as a compact unit with 3 separate outputs for a)high
resolution time measurements; b) energy measurements; c) high rate counting (ECL
standard) – with different optional parameters.
By knowledge of authors commercially available devices don’t provide for these
functions and qualities simultaneously.
TIA Comparison Table (related to task 1)
Parameter
YerPhI TIA
Best available TIA
(expected)
(Analog Modules Inc.,
Model 313A)
Conversion Gain
(20-40) mV/mkA
20 mV/mkA
at 250 MHz (~1.5ns)
Bandwith
170 MHz
75 MHz
at signal source
(detector) capacitance
Cdet = 100 pF
< 10 Ohm
50 Ohm
Input Impedance *
Size
40*20*5 mm
89*49*23 mm
*
This allows decreasing the rise time dramatically in case of signal from large
capacitive detectors.
Additional advantages are:
 Small size;
 Able to manufacture and assemble prototype and production model in
Armenia (very cost effective due to low labor costs).
Time required completing proposed tasks - ~1.5 year (deliverable – final design
and produced models for all 3 items).
Amount of money requesting from ISTC - ~80 k$.