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Photomultiplier Tubes Photon Counting Read-Out-Chip



SPACIROC 3 is a 64-channel chip reading out negative fast input current pulses such as those provided by Multi Anode Photo Multipliers for space-borne and low-power applications. SPACIROC 3 counts photon individually within a Gate Time Unit (GTU).
The 64 inputs from MA-PMT Anodes are read-out by a current amplifier followed by a discriminator. Threshold of that discriminator is set by a 10b DAC and an individual 7b DAC to compensate for the non-uniformity between detector channels. Each channel provides a 100% trigger rate for signal greater than 1/3 photoelectron. The digital part operates continuously and handles data conversion of each Photon Counting channel. The digital data are transmitted through a dedicated parallel communication links within the defined Gate Time Unit (GTU). The ASIC data output rate is 40 MHz. Spaciroc is radiation tolerant and its power consumption is lower than 1 mW/channel.

TRL Technology Readiness Level  9 - Full system running, reliability proven - learn more
Available versions
  • Spaciroc 3 : available
Detector Read-Out  SiPM, MAPMT
Number of Channel 64
Signal Polarity Negative
Sensitivity Trigger on 1/3 photo-electron or 50 fC with a 106 PM gain
Timing Resolution  Not relevant
Dynamic Range Min Gate Time Unit 1.6us, max count 255 per GTU - Photon counting rate > 100MHz
Packaging & Dimension 
  • TQFP 160 28x28mm
Power Consumption

below 1 mW / channel - supply voltage 3.3V

Inputs 64 current inputs

8 serial data outputs (8b) for photon counting

Internal Programmable Features
  • Trigger threshold adjustment (10b)
  • Individual threshold (7b)
Evaluation systems
  • Coming soon