DAQ system for semiconductor radiation detector based on vata chip

Abstract

The readout electronics DAQ system of the semiconductor radiation detector based on VATA chip comprises a system high-voltage power supply, a system general power supply, an FPGA core board, a high-voltage HV generation module, a digital-analog conversion circuit one, a digital-analog conversion circuit two and four VATA control interfaces.The FPGA core board reads commands from a host computer, configures VATA for different working modes, provides first-in-first-out events for data buffering and packaging, and provides high-voltage HV bias for the semiconductor radiation detector, in addition to providing calibration pulses and trigger threshold voltages for VATA, and communicating with the host computer through a universal serial bus and a universal asynchronous receiver / transmitter interface.The application provides a VATA series ASIC general DAQ readout system, which is suitable for different experimental conditions, can control eight VATA chips to work, increases data readout channels, and can be applied in special hard X-ray or gamma-ray detection experiments.

Description

Technical Field

[0001] This invention belongs to the field of data acquisition for semiconductor radiation detectors, specifically relating to a readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip. It is a readout electronics device for a semiconductor radiation detector equipped with a VATA series ASIC for detecting gamma rays or hard X-rays. Background Technology

[0002] VATA series chips are application-specific integrated circuits (ASICs) used for readout of semiconductor radiation detectors. Developed by Ideas Corporation, they are specifically designed for spectral readout of semiconductor radiation detectors, but the ASICs can also be used with other types of radiation detectors. When performing gamma-ray or hard X-ray detection, different VATA series chips often require the design of corresponding DAQ (data acquisition) readout boards, leading to longer experimental cycles and higher costs. Existing DAQs are developed for a specific VATA model ASIC chip, performing specific VATA control and data readout. For different semiconductor detectors detecting radiation, the selected VATA series chips and their quantity vary depending on the actual requirements. Therefore, existing DAQs cannot be applied to radiation detection experiments with different semiconductor detectors. Therefore, seeking a DAQ readout system compatible with all VATA series chips can significantly improve experimental efficiency, shorten the experimental development cycle, and reduce experimental costs. Summary of the Invention

[0003] This invention addresses the problem in the prior art that each version of the VATA series ASIC requires the development of a corresponding DAQ readout system, and provides a readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] The readout electronics DAQ system for a semiconductor radiation detector based on VATA chips is characterized in that the DAQ system can simultaneously control the operation of eight VATA chips, including: a system high-voltage power supply, a system ordinary power supply, an FPGA core board, a high-voltage HV generation module, a digital-to-analog converter circuit one, a digital-to-analog converter circuit two, and four VATA control interfaces, namely VATA control interface one, VATA control interface two, VATA control interface three, and VATA control interface four.

[0006] The system's high-voltage power supply provides the VATA chip with a DC operating voltage referenced to high-voltage HV through VATA control interface one and VATA control interface two; the system's ordinary power supply provides the VATA chip with a DC operating voltage referenced to 0V through VATA control interface three and VATA control interface four.

[0007] The FPGA core board configures the high-voltage HV generation module to output HV, providing a high-voltage HV voltage bias for the semiconductor radiation detector; the FPGA core board configures the first digital-to-analog converter circuit to output a trigger threshold voltage signal HV+VTHR and a scale signal HV+CAL, both with the high-voltage HV as the reference ground, to VATA control interface one and VATA control interface two; the FPGA core board configures the second digital-to-analog converter circuit to output a trigger threshold voltage signal VTHR and a scale signal CAL, both with 0V as the reference ground, to VATA control interface three and VATA control interface four; the FPGA core board configures the VATA operating mode and performs data reading through the four VATA control interfaces;

[0008] The four VATA control interfaces are all interfaces that provide DC operating voltage to the VATA chip, configure the VATA operating mode, trigger threshold voltage signals, and scale signals.

[0009] To optimize the above technical solution, the specific measures also include:

[0010] Furthermore, the system's high-voltage power supply provides HV-2V and HV+1.5V DC operating voltages to the four VATA chips, while the system's ordinary power supply provides -2V and +1.5V DC operating voltages to the remaining four VATA chips.

[0011] Furthermore, isolators are provided between the FPGA core board and the first digital-to-analog converter circuit, between the FPGA core board and the second digital-to-analog converter circuit, between the FPGA core board and the high-voltage HV generation module, and between the FPGA core board and the four VATA control interfaces.

[0012] Furthermore, the DAQ system also includes a USB module and a serial port module. The FPGA core board sends the current system status and read data to the PC through the USB module and the serial port module, and responds to the PC's control and configuration commands.

[0013] Furthermore, the DAQ system also includes an external trigger module, which sends a trigger signal to the FPGA core board to read data from the VATA chip.

[0014] Furthermore, the FPGA core board adopts the AC7A035 core board developed using the XC7A35T-2FGG484I chip.

[0015] Furthermore, the high-voltage HV generation module uses XP Power's CA series high-voltage converter, and the output high-voltage HV is between 100V and 2000V.

[0016] Furthermore, the four VATA control interfaces use 2×20-pin connectors with a pin pitch of 2.0mm.

[0017] Furthermore, the USB module and the serial port module are model numbers FT232H and LC231X, respectively.

[0018] Furthermore, the external trigger module adopts an SN74AVC4T77 44-bit dual-power bus transceiver.

[0019] The beneficial effects of this invention are as follows: This invention provides a universal DAQ system for VATA series ASICs, which is compatible and versatile with the VATA ASIC series. It can be used with any VATA series ASIC to read out raw data from multi-channel semiconductor radiation detectors, such as data readout from cadmium zinc telluride (CdZnTe, CZT) pixel detectors. This effectively shortens the development cycle and saves experimental costs when facing different experimental situations. This DAQ system can also control eight VATA series chips simultaneously, increasing the data readout channels and making it effective in special hard X-ray or gamma-ray detection experiments; alternatively, each VATA chip can be controlled independently, making the readout channels more flexible. Attached Figure Description

[0020] Figure 1 This is a system block diagram of the readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip.

[0021] Figure 2 This is a chip connection diagram of the readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip.

[0022] Figures 3a-3d This is a schematic diagram of the signal interfaces of four VATA control interfaces, corresponding to VATA control interface 1_1, VATA control interface 2_2, VATA control interface 3_1, and VATA control interface 4_2, respectively.

[0023] The attached diagrams are labeled as follows: VATA control interface 1_1, VATA control interface 2_2, VATA control interface 3_1, VATA control interface 4_2, digital-to-analog converter circuit 1_3, digital-to-analog converter circuit 2_4, high-voltage HV generation module 5, system high-voltage power supply 6, system ordinary power supply 7, FPGA core board 8, isolator 9, USB module 10, serial port module 11, external trigger module 12. Detailed Implementation

[0024] The invention will now be described in further detail with reference to the accompanying drawings.

[0025] like Figure 1 and Figure 2 As shown, this invention proposes a readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip, which consists of a system high-voltage power supply 6, a system ordinary power supply 7, an FPGA core board 8, a high-voltage HV generation module 5, a digital-to-analog converter circuit 1 3, a digital-to-analog converter circuit 2 4, a VATA control interface 1_1, a VATA control interface 2_2, a VATA control interface 3 2_1, a VATA control interface 4 2_2, a USB module 10, a serial port module 11, and an external trigger module 12.

[0026] The DAQ readout board (i.e., the DAQ system) is responsible for receiving commands from the host computer (PC), controlling the operating mode of the VATA ASIC, and packaging and uploading digital data to the host. The core of this board is the Xilinx AC7A035 field-programmable gate array (FPGA) core board, specifically FPGA core board 8, equipped with a 200MHz active differential crystal oscillator for the FPGA's master clock. FPGA core board 8 reads commands from the host, configures VATA for different operating modes, provides first-in-first-out events for data buffering and packaging, and provides a high-voltage HV bias to the semiconductor radiation detector. The DAQ readout board also provides trigger threshold voltages and calibration pulses for VATA and communicates with the host via a universal serial bus and a universal asynchronous receiver / transmitter interface. In this embodiment, the DAQ readout board measures 350mm × 250mm.

[0027] When hard X-rays or gamma-ray photons are incident on a semiconductor radiation detector, a large number of electron-hole pairs are generated, proportional to the deposition energy. Under the influence of a high electric field, electrons and holes drift towards the anode and cathode, respectively. The VATA chip collects the analog electronic signals and converts them into digital bits, which are then sent to the FPGA core board 8. The FPGA core board 8 uploads the digital data to the host computer for real-time analysis or offline processing.

[0028] The system power supply is divided into a high-voltage power supply 6 (power supply value HV+5V) and a general-purpose power supply 7 (power supply value 5V). These are supplied by a low-dropout linear regulator (LDO) to provide HV+1.5V, HV-2.0V, HV+3.3V and +1.5V, -2.0V, +3.3V respectively for the DAQ system and VATA. The high voltage provided by the general-purpose DAQ system serves two purposes: first, to provide high voltage to the detector electrodes to reduce charge loss and improve the detector electrodes' ability to collect charge carriers; second, the detector electrodes need to be wire-bonded to the VATA chip, and the VATA chip corresponding to the high-voltage detector electrodes needs to use the high-voltage HV as a reference ground to operate normally. The term "general-purpose" refers to using 0V as a reference ground. In addition to the high-voltage electrodes, all other electrodes of the semiconductor radiation detector need to use 0V as a reference ground, and the corresponding VATA chip also needs to operate with 0V as a reference ground.

[0029] FPGA core board 8 is a high-performance AC7A035 core board developed based on the XILINX ARTIX-7 series XC7A35T-2FGG484I chip. It is mainly used to configure VATA working mode and data reading, and transmit data to the host for real-time analysis or offline processing.

[0030] Isolator 9 uses two models of digital isolators, ADuM260N and ADuM241D, to perform signal level conversion and noise shielding. The isolator in a general-purpose DAQ system has two functions: first, the signals controlled by each FPGA need to pass through the isolator for voltage conversion and matching; second, it isolates the signals at both ends of the isolator to reduce the impact of noise on the system.

[0031] The high-voltage HV generation module 5 uses a high-performance, precise voltage-regulated high-voltage converter from XP Power's CA series. Through FPGA configuration, its output high-voltage HV ranges from 100V to 2000V. HV is mainly used as the reference level for the DAQ readout system and VATA operating in high-voltage environments, as well as the high-voltage HV bias required for the semiconductor radiation detector electrodes.

[0032] Digital-to-analog converter circuit 1 (3) and digital-to-analog converter circuit 2 (4) generate trigger threshold voltage signal VTHR and scale signal CAL respectively in high voltage environment (with HV as reference level) and normal voltage environment (with 0V as reference level) under the configuration of DAC digital-to-analog converter chip on FPGA core board 8, and introduce trigger threshold voltage signal VTHR and scale signal CAL to VATA control interface.

[0033] Of the four VATA control interfaces, VATA control interfaces 1_1 and 1_2 operate in a high-voltage environment, while VATA control interfaces 2_1 and 2_2 operate in a normal-voltage environment. Each set of interfaces consists of a 2×20-pin connector with a pin pitch of 2.0mm. The VATA operating mode control signal, the raw waveform signal of the detector signal acquired at the output, and the digital signal after analog-to-digital conversion are all ultimately controlled by the FPGA core board 8.

[0034] The serial port module 11 and the USB module 10 are selected as LC231X and FT232H respectively, mainly used for communication with the host.

[0035] The external trigger module 12 is implemented using an SN74AVC4T774 4-bit dual-power bus transceiver. It can read data in VATA by inputting an external trigger signal into the FPGA core board 8. It is mainly used in the debugging stage.

[0036] Figure 2 The DAQ system chip connection diagram shown is as follows: Figure 1 The DAQ system block diagram corresponds as follows: System high-voltage power supply 6 and system ordinary power supply 7 correspond to Power_LDO(HV) and Power_LDO respectively; FPGA core board 8 corresponds to FPGA core board; isolator 9 corresponds to isolator; high-voltage HV generation module 5 corresponds to HV_Crol_out; digital-to-analog conversion circuit 1 3 and digital-to-analog conversion circuit 2 4 correspond to DAC generating VTHR and CAL signals module 1 and DAC generating VTHR and CAL signals module 2 respectively; VATA control interface 1_1, VATA control interface 2_2, VATA control interface 3_1, and VATA control interface 4_2 correspond to VATA1 Interface 2x20 pin, VATA2 Interface 2x20 pin, VATA3 Interface 2x20 pin, and VATA4 Interface 2x20 pin respectively; serial port module 11 and USB module 10 correspond to USB / RS232; external trigger module 12 corresponds to external trigger module.

[0037] To achieve versatility, the readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip proposed in this invention specifically includes the following functions:

[0038] Power output: The system high-voltage power supply 6, with high-voltage HV as the reference ground, provides the DC operating voltage of HV-2V and HV+1.5V for the first four VATA chips, and the system ordinary power supply 7, with 0V as the reference ground, provides the DC operating voltage of -2V and +1.5V for the last four VATA chips; the FPGA core board 8 configures the high-voltage HV generation module 5 to output HV, providing the required high-voltage HV voltage bias for the semiconductor radiation detector.

[0039] Data communication: The general-purpose DAQ sends the current system status and collected data to the PC via the serial port module 11 or the USB module 10, and responds to the PC's control and configuration commands.

[0040] VATA threshold signal setting: The FPGA core board 8 configures the digital-to-analog converter circuit 3 and the digital-to-analog converter circuit 4 to output the trigger threshold voltage signal HV+VTHR (with high voltage HV as the reference ground) and the trigger threshold voltage signal VTHR (with 0V as the reference ground) respectively.

[0041] VATA scale signal settings: The FPGA core board 8 configures the digital-to-analog converter circuit 1 3 and the digital-to-analog converter circuit 2 4 to output the scale signal HV+CAL (with high voltage HV as the reference ground) and the signal scale signal CAL (with 0V as the reference ground) respectively.

[0042] VATA External Trigger Setting: The trigger signal is given to the input terminal of the SN74AVC4T774 4-bit dual power supply bus transceiver of the external trigger module 12, and the output signal is given to the FPGA core board 8, so that the data in VATA can be read. This is mainly used in the debugging stage.

[0043] VATA Control Interface: The general-purpose DAQ has four 20x2 pin VATA control interfaces, corresponding to... Figure 2 The signals on the VATA control interface are named as follows: 1_1, 1_2, 2_1, 2_2. Figures 3a-3d As shown, signals with the TOP naming convention in the interface indicate that they are all referenced to HV, meaning they operate in a high-voltage environment, while signals with the BOTTOM naming convention indicate that they are all referenced to OV.

[0044] by Figure 3a Taking the VATA control interface 1-1 as an example:

[0045] TOP_DVDD / TOP_DVSS and TOP_AVDD / TOP_AVSS provide VATA with DC operating voltages of HV-2V and HV+i.5V respectively. The difference between DVDD and DVSS is that they are connected in series with an inductor, and are used for the digital signal section (DVDD) and analog signal section (DVSS) of VATA respectively. VATA_TOP_I1_IN, VATA_TOP_I4_IN, VATA_TOP_I3_1_IN, VATA_TOP_I3_2_IN, VATA_TOP_O5_1 / VATA_TOP_O5B_1 (negative phase of VATA_TOP_O5_1), VATA_TOP_O52 / VATA_TOP_O5B_2 (negative phase of VATA_TOP_O52), VATA_TOP_OUT61 / 2, VATA_TOP_S_LATCH, VATA_TOP_SO, VATA_TOP_S1, and VATA_TOP_S2 are VATA... The Mode-IO signal interface is used to configure the VATA's operating mode. The Mode-IO interfaces of the VATA series chips are identical; only the interface order varies depending on the specific VATA chip model. This allows the general-purpose DAQ VATA control interface to control different VATA chip models. When two VATA chips are cascaded, the VATA_TOP_I3_1_IN, VATA_TOP_I3_2_IN, VATA_TOP_O5_1, and VATA_TOP_O5_2 signals provided by the VATA control interface can be used for VATA chip cascading. If cascading is not used, the VATA chips can also be configured individually via the Mode-IO signal interface.

[0046] VATA_TOP_VTHR_1 and VATA_TOP_VTHR_2 provide trigger threshold voltage signal interfaces for the VATA chip; VATA_TOP_CAL_PULSE1 (analog signal scale) / VATA_TOP_CALD_1 (digital signal scale) and VATA_TOP_CAL_PULSE2 (analog signal scale) / VATA_TOP_CALD_2 (digital signal scale) provide scale signal interfaces for the VATA chip; VATA_TOP_OUTP_1 / 2 represent the analog signals sampled by the VATA chip; TOP_GND indicates that HV is the reference ground.

[0047] Figures 3b-3d The other three VATA control interfaces shown adopt the same design, so they will not be described in detail here.

[0048] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip, characterized in that, The DAQ system can simultaneously control eight VATA chips, including: a system high-voltage power supply (6), a system ordinary power supply (7), an FPGA core board (8), a high-voltage HV generation module (5), a digital-to-analog conversion circuit one (3), a digital-to-analog conversion circuit two (4), and four VATA control interfaces, namely VATA control interface one (1_1), VATA control interface two (1_2), VATA control interface three (2_1), and VATA control interface four (2_2). The system high-voltage power supply (6) provides the VATA chip with a DC operating voltage with high voltage HV as the reference ground through VATA control interface one (1_1) and VATA control interface two (1_2); the system ordinary power supply (7) provides the VATA chip with a DC operating voltage with 0 V as the reference ground through VATA control interface three (2_1) and VATA control interface four (2_2); the system high-voltage power supply (6) provides four VATA chips with DC operating voltages of HV-2 V and HV+1.5 V, and the system ordinary power supply (7) provides the remaining four VATA chips with DC operating voltages of -2 V and +1.5 V; The FPGA core board (8) configures the high-voltage HV generation module (5) to output HV, providing a high-voltage HV voltage bias for the semiconductor radiation detector; the FPGA core board (8) configures the first digital-to-analog converter circuit (3) to output a trigger threshold voltage signal HV+VTHR and a scale signal HV+CAL, both with high-voltage HV as the reference ground, to VATA control interface one (1_1) and VATA control interface two (1_2); the FPGA core board (8) configures the second digital-to-analog converter circuit (4) to output a trigger threshold voltage signal HV+VTHR and a scale signal HV+CAL, both with high-voltage HV as the reference ground, to VATA control interface one (1_1) and VATA control interface two (1_2); the FPGA core board (8) configures the second digital-to-analog converter circuit (4) to output a high-voltage HV voltage bias, both with high-voltage HV as the reference ground. V is the trigger threshold voltage signal VTHR and the scale signal CAL of the reference ground to VATA control interface three (2_1) and VATA control interface four (2_2); the FPGA core board (8) configures the VATA working mode and reads data through the four VATA control interfaces; isolators are provided between the FPGA core board (8) and the first digital-to-analog converter circuit (3), between the FPGA core board (8) and the second digital-to-analog converter circuit (4), between the FPGA core board (8) and the high voltage HV generation module (5), and between the FPGA core board (8) and the four VATA control interfaces; The four VATA control interfaces are all interfaces that provide DC operating voltage to the VATA chip, configure the VATA operating mode, provide trigger threshold voltage signals and scale signals.

2. The readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip as described in claim 1, characterized in that: The DAQ system also includes a USB module (10) and a serial port module (11). The FPGA core board (8) sends the current system status and read data to the PC through the USB module (10) and the serial port module (11), and responds to the PC's control and configuration commands.

3. The readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip as described in claim 1, characterized in that: The DAQ system also includes an external trigger module (12), which sends a trigger signal to the FPGA core board (8) to read data from the VATA chip.

4. The readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip as described in claim 1, characterized in that: The FPGA core board (8) is an AC7A035 core board developed using the XC7A35T-2FGG484I chip.

5. The readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip as described in claim 1, characterized in that: The high-voltage HV generation module (5) uses XP Power's CA series high-voltage converter, and the output high-voltage HV is between 100V and 2000V.

6. The readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip as described in claim 1, characterized in that: The four VATA control interfaces use 2×20 pin connectors with a pin pitch of 2.0mm.

7. The readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip as described in claim 2, characterized in that: The USB module (10) and the serial port module (11) are model numbers FT232H and LC231X, respectively.

8. The readout electronics DAQ system for a semiconductor radiation detector based on a VATA chip as described in claim 3, characterized in that: The external trigger module (12) adopts an SN74AVC4T774 4-bit dual-power bus transceiver.

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