We designed a high-performance Digital Pulse Processor (DPP) as a fully open-source and open-hardware platform. Our goal is to launch it as a Crowd Supply project so the wider radiation-instrumentation community can build, modify, and improve it.
At the front end, the system supports precise analog conditioning for detector signals. A 3.2 µs pole-zero setting is included, which is crucial for properly compensating preamplifier decay and achieving stable energy measurements in spectroscopy applications. The board also provides a programmable gain chain up to 100×, with 16 logarithmically spaced gain selections to cover a wide dynamic range while maintaining good resolution across different detector types and count-rate conditions.
For digitization, we use an AD9254 150 MSPS ADC to sample the conditioned detector waveform. Digital processing is performed with a trapezoidal shaping chain, where key shaping parameters are fully configurable:
This allows the DPP to be tuned for a wide range of detectors and applications—from fast scintillators to slower semiconductor detectors—balancing throughput, resolution, and pulse pile-up performance.
For debugging, diagnostics, and flexible triggering/output experiments, the board includes an AD9742 DAC. This enables waveform reconstruction, test outputs, and support for advanced trigger strategies during development and system integration.
At the heart of the platform is an AMD Zynq XC7Z010 SoC, combining FPGA fabric for real-time DSP with an ARM processor for control, configuration, and communications. The system is designed to support embedded Linux and includes:
For connectivity and integration into larger systems, the platform provides multiple standard interfaces:
The digital processing pipeline runs at 150 MHz and includes essential spectroscopy features such as:
Configurable shaping and gain control for adapting to different detector responses and measurement goals
The board is Linux-capable. We have successfully booted PetaLinux and verified full operation of the onboard peripherals and interfaces.
For testing, we used our charge-sensitive preamplifier (CSP) module together with our CSP test box. The preamplifier is a JFET-based, fully discrete design, and it will also be released as open-source and open-hardware. On the Crowd Supply project page, it will be listed alongside the Digital Pulse Processor board—below you can see the photo of the the charge-sensitive preamplifier.
During these initial tests, we did not enable the full gain coverage; instead, we used a limited subset of gain settings for quick validation. The fast filter is also configurable, and the noise threshold can be adjusted to match the detector noise level and reduce false triggers. The resulting spectrum and the corresponding configuration are shown in the figure below.
This hardware is not limited to digital pulse processing. It can also be used as a high-speed digitizer for detector readout or for capturing and processing waveforms from other analog front-end circuits. To support a wide range of applications, the design includes configurable I/O with 20 FPGA pins and 10 SoC pins available for user-defined purposes.
In addition, we designed a base board to complement the DPP module. While the base board has not yet been manufactured, it is intended to provide a complete detector-readout infrastructure, including:
High-voltage rails up to ±1500 V
A 25–75 V bias supply for SiPM operation
Clean, low-noise supply rails for analog front ends and preamplifiers
The low-voltage rails can be set easily using resistor-defined configurations (e.g., 5 V, 8.5 V, and 12 V). The positive and negative high-voltage outputs can also be configured with simple resistor settings and are controlled by an STMicroelectronics STM32G491 microcontroller. The microcontroller receives control and status information from the FPGA via UART.
For location-aware measurements and advanced field deployments, we also integrated a u-blox ZED-F9P GNSS/RTK module to provide high-accuracy positioning when required.
A rendered image of the designed base board is shown below.
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We’re a small team, and this is an ambitious project. We’re not “business people” in the traditional sense—we’re young scientists (our team is under 30), and we genuinely love radiation detection and materials science. We’re driven more by curiosity and the desire to contribute to the community than by profit. Building a hardware like this is challenging, but we believe making high-performance tools accessible is worth the effort.
We also really like ImpulseQT, and we’d love to explore a version that supports this hardware platform.
If you have any questions, feel free to ask in this post or reach out directly. You can also contact us by email at mehmet@muontek.com.tr
