The CA3 is an ASIC with 32/64-channels for energy resolved single-photon counting optimized for CZT/CdTe detectors. Each channel consists of a preamplifier, two shaping amplifiers, 3 or 6 (depending on operating mode) discriminators and 16-bit counters.
The CA3 has to main modes: 32 channel with 6 energy levels discriminated or with 64 channels and 3 energy levels discriminated. Each energy level is configured globally from input pads and can be adjusted per channel by internal DACs. The counters are outputted through a parallel interface, which makes it possible to connect multiple CA3 on the same bus.
Keywords: Energy Resolved Photon Counting, Singe-Photon Counting, X-Ray and Gamma-Ray Tomography
|Number of inputs||32 / 64|
|Input charge range||0 fC to -4.2 fC|
|Shaping time||50 ns|
|Nominal capacitive load||10 pF|
|Equivalent Noise Charge (ENC)||105e + 40e/pF|
|Trigger threshold||Adjustable per channel|
|Trigger outputs||Common trigger output for all channels|
|Outputs||16-bit counter parallel interface with overflow|
|Test and calibration||1 digital in, 1 external capacitor and 1 internal capacitor|
|Power consumption||210 mW (32 channel mode), 270 mW (64 channel mode)|
- J.P. Schlomka et al., “Experimental feasibility of multi-energy photoncounting K-edge imaging in pre-clinical computed tomography”, Phys. Med. Biol., 53 (2008) 4031-4047.
- X. Wang, et al., “A Digital Line-Camera for Energy Resolved X-ray Photon Counting”, Proc. Med. Imag. Conf. (NSS/MIC), IEEE 2009.