CN114690234A - PRE _ ASIC chip and modular integrated front end based on semiconductor detector - Google Patents

Abstract

The invention relates to a PRE _ ASIC chip and a modular integrated front end based on a semiconductor detector. The front end includes a semiconductor detector, an integrated PRE _ ASIC chip, a printed PCB board and a shielding structure. The semiconductor detector converts the loss energy of the electric particles incident on the semiconductor detector into a charge signal; the PRE _ ASIC chip comprises charge sensitive PRE-amplification, pulse shaping, peak holding, main amplification and threshold triggering circuits; the charge sensitive pre-amplifying circuit pre-amplifies the charge signal and converts the charge signal into a pulse signal; the pulse shaping circuit converts the pulse signal into a voltage signal; the main amplifying circuit amplifies the voltage signal for the second time; the peak holding circuit carries out voltage peak holding on the voltage signal after the main amplification and outputs the voltage signal; the threshold trigger circuit converts the main amplified voltage signal into a trigger signal and outputs the trigger signal; the semiconductor detector and the PRE _ ASIC chip are disposed on the same printed PCB board. The invention reduces the structural size and weight of the detection module, reduces the interference of external noise and improves the signal-to-noise ratio.

Description

A PRE_ASIC chip and its modular integrated front-end based on semiconductor detectors

technical field

The invention belongs to the technical field of particle radiation measurement, and in particular relates to a PRE_ASIC chip and a modular integrated front end based on a semiconductor detector.

Background technique

Semiconductor sensors are currently the most widely used sensors in particle radiation measurement. It is a radiation detector with a semiconductor material as the detection medium. Its basic principle is that charged particles generate electron-hole pairs in the sensitive volume of the semiconductor detector, and the electron-hole pairs drift under the action of an external electric field to output a charge signal. Commonly used semiconductor detectors include PN junction semiconductor detectors and lithium drift semiconductor detectors.

Semiconductor detectors are mainly used in the field of particle radiation detection. They can measure charged particles such as medium and high energy electrons and protons. The energy range covers about 10keV to several hundred MeV. It is suitable for particle detectors mounted on spacecraft to measure space particle radiation. Such as medium and high energy electron detectors and proton detectors. At the same time, it can also be used to measure various radiation effects produced by charged particles, such as particle radiation LET spectrum detectors, single particle detectors, etc.

At present, my country's particle radiation measurement technology is in the stage of development and improvement, and there is still a certain gap between the detection technology and the international level. The existing particle radiation measurement device basically adopts the sensor system and the front-end electronics design, and the front-end electronics are all realized by electronic components, including various integrated devices such as preamplifier, main amplifier, peak hold and trigger, etc. The circuit design The scale is more complex, the size power consumption is also large, and it is not convenient for circuit debugging and performance testing. Importantly, the design of the sensor system and front-end electronics makes it more susceptible to external noise interference, and it is difficult to improve particle measurement indicators.

The problems existing in the prior art are: the current particle radiation detection devices are all designed using a sensor system and front-end electronics, and the front-end electronics are designed and implemented by electronic components. Specifically, on the one hand, the particle radiation measurement devices are all mature products, and the sensor system and front-end electronics are designed in separate parts, which have large structural size and weight, and take up a lot of resources. Due to external noise interference, it is difficult to improve the measurement accuracy and other indicators; on the other hand, because the front-end electronics are designed with electronic components, including a variety of integrated devices such as preamplifier, main amplifier, peak hold and trigger, the circuit design is more complicated. The size and power consumption are large, and it is not convenient for circuit debugging and performance testing.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned defects in the prior art, the present invention proposes a modular integrated front end, in particular to a modular integrated front end based on a semiconductor detector; the modular integrated front end provided by the present invention overcomes the problems in the current particle radiation measurement technology The sensor system and the front-end electronics are divided into two parts. The weak signal output of the sensor is easy to be interfered by external noise and the detection accuracy is difficult to improve. It also overcomes the problem that the front-end electronics in the prior art are designed with different electronic components, resulting in difficult circuit design and circuit design. In addition, it overcomes the disadvantages of high power consumption and large size of the existing particle measuring device.

The modular integrated front-end based on the semiconductor detector of the present invention can measure the charged particle radiation in real time, has the advantages of high integration, low power consumption, strong anti-interference ability, etc., and can be widely used in particle radiation measurement loads, such as medium High-energy electron detectors, medium and high-energy proton detectors, particle radiation LET spectrometers and single particle detectors, etc. In addition, it can also be used in space X-ray detection based on silicon semiconductor detectors, elemental analysis in deep space detection, high-energy physics experiments, X-ray diffraction XRD, medical CT and other related fields. However, at present, the integrated front-end module design based on semiconductor detectors is not used in particle radiation measurement technology.

The present invention provides a PRE_ASIC chip, the PRE_ASIC chip includes: a charge-sensitive preamplifier circuit, a pulse shaping circuit, a main amplifier circuit, a peak hold circuit and a threshold trigger circuit; wherein,

The charge-sensitive pre-amplifier circuit is used to perform charge-sensitive pre-amplification on the charge signal and convert it into a pulse signal;

The pulse shaping circuit is used to convert the pulse signal into a voltage signal with certain rising edge information, and transmit it to the main amplifying circuit;

The main amplifying circuit adopts a negative feedback amplification form, and is used to amplify the formed voltage signal twice, and transmit it to the peak hold circuit and the threshold trigger circuit;

The peak hold circuit is used to hold the peak value of the voltage amplitude signal after the main amplification and output it to the subsequent circuit;

The threshold trigger circuit is used to convert the main amplified voltage signal into a trigger signal according to the initially set threshold signal, and output it to the subsequent circuit.

The invention provides a modular integrated front end based on a semiconductor detector, the integrated front end includes the following modules: a semiconductor detector (1) and a shielding structure (3) a printed PCB board (4) and a PRE_ASIC chip (2); The PRE_ASIC chip (2) is used to receive the charge signal transmitted by the semiconductor detector (1), process it and then output it, and the output signal is used to calculate the energy information of the charged particles; the semiconductor detector The device (1) and the PRE_ASIC chip (2) are arranged on the same printed PCB board (4); the shielding structure (3) is used to shield external interference;

the semiconductor detector (1), for generating a charge signal reflecting the magnitude of the energy lost by the charged particles therein, and transmitting it to the PRE_ASIC chip (2);

The PRE_ASIC chip (2) includes circuit functions such as charge-sensitive preamplification, pulse shaping, main amplification, peak hold, and threshold triggering; wherein,

The charge-sensitive pre-amplifier circuit is used to perform charge-sensitive pre-amplification on the charge signal output by the semiconductor detector and convert it into a pulse signal;

The pulse shaping circuit is used to convert the pulse signal into a voltage signal with certain rising edge information, and transmit it to the main amplifying circuit;

The main amplifying circuit adopts a negative feedback amplification form, and is used to amplify the formed voltage signal twice, and transmit it to the peak hold circuit and the threshold trigger circuit;

The peak hold circuit is used to hold the peak value of the voltage amplitude signal after the main amplification and output it to the subsequent circuit;

The threshold trigger circuit is used to convert the main amplified voltage signal into a trigger signal according to the initially set threshold signal, and output it to the subsequent circuit;

The PRE_ASIC chip (2), based on the received charge signal output by the semiconductor detector, performs charge-sensitive pre-amplification, pulse shaping and main amplification of the signal to obtain the energy loss information of the charged particles in the semiconductor detector, specifically Steps include:

The integrated front end obtains the voltage amplitude information of each corresponding charged particle; obtains the different threshold voltages of the space charged particles of each corresponding energy through theoretical calculation using the obtained voltage amplitude information, and compares them; based on the comparison The result is combined with the known thickness of the semiconductor detector (1) to obtain the corresponding energy information of the space charged particles.

As an improvement of the above method, the part of the shielding structure (3) facing the semiconductor detector (1) is designed to be open, and the remaining part is designed to be closed.

As another improvement of the above method, the material of the shielding structure (3) is metal.

As another improvement of the above method, the semiconductor detector (1) includes: a PN junction type or lithium drift type semiconductor detector, the thickness of the detector is about several tens of microns to several millimeters, and the sensitive area is several square millimeters to about thousand square millimeters.

As a further improvement of the above method, the printed layouts of the semiconductor detector (1) and the PRE_ASIC chip (2) are designed on the same printed PCB board (4), and are adjacent to each other, specifically: PRE_ASIC The distance between the chip (2) and the semiconductor detector (1) is within 10 mm.

As a further improvement of the above method, the printed PCB board (4) is fastened and installed in the shielding structure (3) by screws, so as to reduce external noise interference.

The beneficial effects of the present invention compared with the prior art are:

The semiconductor detector-based modular integrated front end of the present invention adopts a dedicated integrated PRE_ASIC chip, and the semiconductor detector and the PRE_ASIC chip are modularly designed, with positive/negative charge input, pulse shaping, main amplification, peak signal hold and threshold value. Trigger output and other functions; through the modular integrated front-end design, the structure size and weight of the detector module can be reduced. When used to design a charged particle radiation measurement device, the detector can be combined with multiple integrated front-ends to achieve flexible combinations. , reducing the complexity of the detector and front-end electronics design; and through the modular design and shielding structure of the detector, the distance between the detector output and the charge preamplifier circuit is shortened, and the interference of external noise is effectively reduced, so as to achieve particle detection. The low noise and high intensive requirements of the device improve the signal-to-noise ratio.

Description of drawings

1 is a schematic structural diagram of a semiconductor detector-based modular integrated front-end provided by an embodiment of the present invention;

2 is a layout diagram of a printed board of a semiconductor detector-based modular integrated front end provided by an embodiment of the present invention;

FIG. 3 is a circuit connection block diagram of the semiconductor detector-based modular integrated front-end according to the present invention.

Reference number:

1. Semiconductor detector 2. PRE_ASIC chip

3. Shielding structure 4. Printed PCB board

Detailed ways

The present invention will now be further described with reference to the accompanying drawings.

The working principle of the semiconductor detector-based modular integrated front-end according to the present invention is shown in FIG. 3 , which specifically includes the following steps:

When a charged particle is incident on a semiconductor detector, different energy losses will be generated in the corresponding semiconductor detector. The output of the semiconductor detector reflects the charge signal of the energy relationship of the incident particle, that is, the charge signal output by the semiconductor detector passes through the semiconductor detector. The FRE_ASIC device connected to the device, after charge-sensitive pre-amplification, pulse shaping, main amplification and peak signal hold, obtain the voltage amplitude information of each corresponding charged particle; through theoretical calculation, obtain the corresponding energy of each The different threshold voltages of the space charged particles are compared and compared; based on the comparison results and in combination with the known thickness of the silicon semiconductor detector, the energy information of the corresponding space charged particles is obtained.

As shown in FIG. 1, the modular integrated front-end based on semiconductor detectors according to the present invention includes the following modules: semiconductor detector 1, PRE_ASIC chip 2, printed PCB board 4 and shielding structure 3; semiconductor detector 1 and PRE_ASIC The chip 2 is installed on the same printed PCB board 4, as shown in FIG. 2; the printed PCB board 4 is fastened and installed in the corresponding metal shielding structure 3 by screws to reduce external noise interference; wherein,

The semiconductor detector 1 is used to output a charge signal reflecting the deposition energy of the charged particles in space, and transmit it to the PRE_ASIC chip 2;

The PRE_ASIC chip 2 includes: charge-sensitive preamplification, pulse shaping, main amplification, peak hold and threshold triggering circuits; wherein,

The charge-sensitive pre-amplifier circuit is used to perform charge-sensitive pre-amplification on the charge signal output by the semiconductor detector and convert it into a pulse signal;

The pulse shaping circuit is used to convert the pulse signal into a voltage signal with certain rising edge information, and transmit it to the main amplifying circuit;

The main amplifying circuit adopts a negative feedback amplification form, and is used to amplify the formed voltage signal twice, and transmit it to the peak hold circuit and the threshold trigger circuit;

The peak hold circuit is used to hold the peak value of the voltage amplitude signal transmitted by the main amplifier circuit and output it to a subsequent circuit;

The threshold trigger circuit is used to convert the voltage signal transmitted by the main amplifier circuit into a trigger signal according to an initially set threshold signal.

The PRE_ASIC chip 2, based on the received charge signal output by the semiconductor detector 1, performs charge-sensitive pre-amplification, pulse shaping and main amplification of the signal to obtain the energy loss information of the charged particles in the semiconductor detector 1, specifically: Steps include:

Based on the received charge signal output by the semiconductor detector 1, the charge sensitive preamplification method is adopted, and after pulse shaping, main amplification and peak signal holding, the voltage amplitude information of each corresponding charged particle is obtained; through theoretical calculation , obtain the different threshold voltages of the space charged particles of each corresponding energy, and compare them; based on the comparison results and in combination with the known thickness of the silicon semiconductor detector 1 , obtain the corresponding energy information of the space charged particles.

The semiconductor detector 1 includes: a PN junction type or lithium drift type semiconductor detector, the thickness of the detector is about several tens of microns to several millimeters, and the sensitive area is several square millimeters to about a thousand square millimeters.

The printed layouts of the semiconductor detector 1 and the PRE_ASIC chip 2 are designed on the same printed PCB board 4 and are adjacent to each other.

In the embodiment, the metal selected for the metal material of the shielding structure 3 is copper or iron.

It can be seen from the above that the present invention can reduce the structural size and weight of the detector module, and through the modular design and shielding structure of the detector, the distance between the detector output and the charge preamplifier circuit is shortened, and the interference of external noise is effectively reduced. , so as to meet the requirements of low noise and high intensity of particle detection devices, and improve the signal-to-noise ratio.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention will not depart from the spirit and scope of the technical solutions of the present invention, and should be included in the present invention. within the scope of the claims.

Claims (7)

1. A PRE ASIC chip, said PRE ASIC chip comprising: the circuit comprises a charge sensitive preamplification circuit, a pulse shaping circuit, a main amplification circuit, a peak value holding circuit and a threshold value trigger circuit; wherein,

the charge sensitive preamplification circuit is used for carrying out charge sensitive preamplification on the charge signal and converting the charge signal into a pulse signal;

the pulse shaping circuit is used for converting the pulse signal into a voltage signal with certain rising edge information and transmitting the voltage signal to the main amplifying circuit;

the main amplifying circuit adopts a negative feedback amplifying form and is used for carrying out secondary amplification on the formed voltage signal and transmitting the voltage signal to the peak holding circuit and the threshold triggering circuit;

the peak holding circuit is used for carrying out peak holding on the voltage amplitude signal subjected to main amplification and outputting the voltage amplitude signal to a subsequent circuit;

and the threshold trigger circuit is used for converting the main amplified voltage signal into a trigger signal according to the initially set threshold signal and outputting the trigger signal to a subsequent circuit.

2. A modular integrated front-end based on a semiconductor detector, characterized in that the integrated front-end comprises the following modules: the device comprises a semiconductor detector (1), a PRE _ ASIC chip (2), a printed PCB (4) and a shielding structure (3);

the semiconductor detector (1) is used for generating a charge signal reflecting the energy loss of the charged particles in the semiconductor detector and transmitting the charge signal to the PRE _ ASIC chip (2); the PRE _ ASIC chip (2) is used for receiving the charge signal transmitted by the semiconductor detector (1), processing the charge signal and then outputting the processed charge signal, and the output signal is used for calculating energy information of charged particles; the semiconductor detector (1) and the PRE _ ASIC chip (2) are arranged on the same printed PCB (4); the shielding structure (3) is used for shielding external interference;

the PRE _ ASIC chip (2) includes: the circuit comprises a charge sensitive preamplification circuit, a pulse shaping circuit, a main amplification circuit, a peak value holding circuit and a threshold value trigger circuit; wherein,

the charge sensitive preamplification circuit is used for carrying out charge sensitive preamplification on a charge signal output by the semiconductor detector and converting the charge signal into a pulse signal;

the pulse shaping circuit is used for converting the pulse signal into a voltage signal with certain rising edge information and transmitting the voltage signal to the main amplifying circuit;

the main amplifying circuit adopts a negative feedback amplifying form and is used for carrying out secondary amplification on the formed voltage signal and transmitting the voltage signal to the peak holding circuit and the threshold triggering circuit;

the peak holding circuit is used for carrying out peak holding on the voltage amplitude signal subjected to main amplification and outputting the voltage amplitude signal to a subsequent circuit;

the threshold trigger circuit is used for converting the main amplified voltage signal into a trigger signal according to an initially set threshold signal and outputting the trigger signal to a subsequent circuit;

the integrated front end obtains voltage amplitude information of each corresponding charged particle; obtaining the threshold voltage corresponding to each space charged particle with different energy through theoretical calculation by using the obtained voltage amplitude information, and comparing; based on the comparison result in combination with the known thickness of the semiconductor detector (1), energy information of the corresponding spatially charged particles is obtained.

3. Modular integrated front-end based on semiconductor detectors according to claim 2, characterized in that the shielding structure (3) is open in its part facing the semiconductor detector (1) and closed in its remaining part.

4. Modular integrated front-end based on a semiconductor detector according to claim 2, characterized in that the material of the shielding structure (3) is metal.

5. A semiconductor detector based modular integrated front-end according to claim 2, characterized in that the semiconductor detector (1) comprises: the thickness of the PN junction type or lithium drift type semiconductor detector is dozens of micrometers to several millimeters, and the sensitive area is several square millimeters to thousands of square millimeters.

6. The semiconductor detector-based modular integrated front-end according to claim 2, characterized in that the printed layouts of the semiconductor detector (1) and the PRE _ ASIC chip (2) are designed on the same printed PCB board (4) and are adjacent, in particular: the distance between the PRE _ ASIC chip (2) and the semiconductor detector (1) is within 10 mm.

7. Modular integrated front-end based on semiconductor detectors according to claim 2, characterized in that the printed PCB board (4) is mounted inside the shielding structure (3) by screw fastening.

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