A Configurable Readout Circuit for Detector Signal Conditioning

This work describes a cost-effective circuit for precision conditioning of radiation detectors. The easily configurable readout electronics allows acquiring either DC currents or pulse charge packets, thus satisfying the main requirements for the signal conditioning of detectors under continuous or pulsed irradiation. A precision switched integrator is the core of the front-end, whereas the system versatility is guaranteed by exploiting high performance peripherals integrated in the microcontroller that implements the timing control of the readout electronics. In particular, a current-to-time measurement method is carried out for DC-signal acquisitions, thus mitigating errors due to offset voltages. On the other hand, a two-phase integration procedure is performed for pulsed-current measurements reducing both the offset voltage and the leakage current contributions on the measurements, thereby increasing the system accuracy. The prototypal circuit has been tested in relevant environments for acquiring the signal photogenerated by diamond detectors irradiated by ultraviolet light (continuous) or high-energy X-ray photons (pulsed). Experimental results demonstrate the excellent performance of the proposed system in terms of linearity (R2 = 0.99999), a resolution of 10-bit, and the real-time monitoring capability for pulsed irradiation with repetition frequencies up to 1 kHz.