Low power multi-channel integrated photon detector amplifier and digitizer


Technology abstract

An integrated circuit for photon detection and timing, designed in Norway by a commercial company and manufactured in Austria. The circuit can be used in applications where extremely low levels of light is to be detected such as reading out x- and gamma ray scintillator detectors for gamma spectroscopy and imaging or Positron Emission Tomography, PET. Other possible uses may be LIDAR. The main advantages are small size and low power. Company is seeking customers for the product.

Technology Description

The IDE3380is a general-purpose integrated circuit (IC) for the readout of photon detectors, such as photomultiplier tubes (PMTs), silicon photomultipliers (SiPMs), and multi-pixel photon counters (MPPCs).
The IC has 16 input channels and one summing channel. Each channel can be used for pulse-height spectroscopy and timing. The summing channel is important for the readout of detector arrays with monolithic scintillators. The programmable shaping time of 200 ns, 400 ns, 800 ns, or 1600 ns allows for pulse-height spectroscopy using various scintillators. The current-mode input stage (CMIS) is designed for large negative charge (‑16 nC, ‑8 nC, ‑4 nC, ‑0.4 nC) depending on the programmable attenuation and it accommodates large capacitive load (several nF) and large leakage current (up to ‑10 µA from dark counts). Alternatively, the CMIS can be bypassed to allow for positive charge depending on programmable gain (+40 pC, +4 pC, +0.4 pC).
The IC contains one 12-bit analog-to-digital converter (ADC) that allows for digitization of the pulse heights from all channels, including the summing channel at a sampling rate of 50 ksps. Every channel output is available for external use and provides either the pulse height or a digital trigger/timing pulse with fixed width or time-over-threshold. The programmable channel output facilitates many applications, such as external waveform sampling and digitization, pulse height and time spectroscopy, pulse counting, triggering, and time-over-threshold.
The IC operates at 3.3 V supply voltage and dissipates about 15 mW without CMIS and 30 mW with CMIS active. To save power, any channel or function can be powered down. The ASIC has a serial peripheral interface (SPI) for programming its register settings and for slow ADC data readout. Faster readout with up to 1 Mbit/s is possible via a serial data transmission line. The IC has been designed to be latch-up immune and resilient to single event upsets.

Innovations & Advantages

The technology has been developed to facilitate the transition from vacuum tube based photon detectors, photomultipliers, PMT, to silicon based photomultipliers, SiPMs. As SiPMs are considerably smaller than PMTs and consume less power the offered IC technology enables higher density devices while simultaneously lowering power consumption and cost for low light photon detection.  In an application this can be translated to higher spacial and spectroscopic resolution at similar or lower cost as conventional technology.

Further Information

The IC has been designed with an extended operating temperature for use in space. Used in a gamma spectrometer with silicon photomultipliers and a LaBr scintillator the energy resolution at 662keV has been measured to be better than 4% full width-half-maximum with a lower detection limit at 40keV or lower.

Current and Potential Domains of Application

Diagnostic medical imaging, positron emission tomography and single photon emission tomography.
Gamma spectroscopy for environmental monitoring and survey, nuclear industry.
LIDAR applications in robotics and automotive.