A device and method for extending the dynamic range of a charge-sensitive amplifier.

Abstract

This invention relates to an apparatus and method for extending the dynamic range of a charge-sensitive amplifier. The apparatus includes a detector, a high-voltage isolation shunt capacitor bank, a charge-sensitive amplifier bank, and a voltage output and digitization module. The charge-sensitive amplifier bank comprises several charge-sensitive amplifiers. The detector outputs a charge signal. The high-voltage isolation shunt capacitor bank distributes the total charge signal output by the detector to the charge-sensitive amplifier bank according to the shunt capacitor ratio and isolates the high voltage at the detector end. Each charge-sensitive amplifier has the same conversion gain and converts the distributed charge signal into a voltage signal. The voltage output and digitization module processes the voltage signal and reconstructs the input total charge signal based on the charge conservation relationship. This invention can be widely applied in the fields of nuclear detection and signal processing technology.

Description

Technical Field

[0001] This invention relates to the field of nuclear detection and signal processing technology, and in particular to an apparatus and method for extending the dynamic range of a charge-sensitive amplifier (CSA). Background Technology

[0002] Charge-sensitive amplifiers are widely used in nuclear radiation detection, particle physics experiments, and photodetectors due to their advantages such as low noise and high stability. A typical charge-sensitive amplifier mainly consists of a high-gain operational amplifier and an integrating feedback capacitor, and its output voltage... V out With input charge Q in The relationship is V out =Q in / C f ( C f (For feedback capacitor).

[0003] Traditional charge-sensitive amplifiers suffer from limited dynamic range, specifically manifested in the following ways: 1) Large signal saturation: When the detector outputs a large amount of charge, the CSA output voltage exceeds the power supply voltage, resulting in saturation clipping; 2) Small signal overwhelming: When the detector outputs a small amount of charge, the CSA output voltage is lower than the noise floor, making effective detection impossible; 3) Conflicting dynamic range: The gain of a single CSA is fixed, making it impossible to simultaneously achieve both large signal unsaturation and high signal-to-noise ratio for small signals.

[0004] To extend the dynamic range of charge-sensitive amplifiers, several solutions have been proposed in existing technologies, such as the variable feedback capacitor method: switching feedback capacitors of different values ​​by switching, but this method has limited switching speed, cannot handle high-speed pulse signals, and there is charge loss during the switching process; the logarithmic amplifier method: can compress the dynamic range, but sacrifices linearity and measurement accuracy, and is not suitable for quantitative analysis.

[0005] Therefore, there is an urgent need for a device and method that can effectively extend the dynamic range of charge-sensitive amplifiers without sacrificing linearity and signal-to-noise ratio. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a device and method for extending the dynamic range of a charge-sensitive amplifier, which can solve the problems of limited dynamic range, large-signal saturation, and insufficient small-signal signal-to-noise ratio of a single CSA in the prior art without sacrificing linearity and signal-to-noise ratio.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: On the one hand, it provides a device for extending the dynamic range of a charge-sensitive amplifier, including a detector, a high-voltage isolation shunt capacitor bank, a charge-sensitive amplifier bank, and a voltage output and digitization module, wherein the charge-sensitive amplifier bank includes a plurality of charge-sensitive amplifiers; The detector is used to output charge signals; The high-voltage isolation shunt capacitor bank is used to distribute the total charge signal output by the detector to the charge-sensitive amplifier bank according to the shunt capacitor ratio, and to isolate the high voltage at the detector end; The charge-sensitive amplifiers in the charge-sensitive amplifier group have the same conversion gain, and the charge-sensitive amplifiers are used to convert the allocated charge signal into a voltage signal; The voltage output and digitization module is used to process the voltage signal and reconstruct the input total charge signal based on the charge conservation relationship.

[0008] Furthermore, the high-voltage isolation shunt capacitor bank includes several shunt capacitors connected in parallel; one end of each of the several shunt capacitors connected in parallel is connected to the output terminal of the detector, and the other end of each of the several shunt capacitors connected in parallel is connected to the input terminal of the charge-sensitive amplifier in the charge-sensitive amplifier bank.

[0009] Furthermore, the number of charge-sensitive amplifiers in the charge-sensitive amplifier group is the same as the number of shunt capacitors in the high-voltage isolation shunt capacitor group, and one of the shunt capacitors in the high-voltage isolation shunt capacitor group and the corresponding charge-sensitive amplifier in the charge-sensitive amplifier group form a corresponding branch channel.

[0010] Furthermore, the voltage output and digitization module includes: The signal processing unit is used to filter, shape, peak protect, and digitize the voltage signal to obtain the processed voltage signal. The branch channel selection unit is used to determine the unsaturated and unflooded branch channels based on the dynamic range of the input charge signal and the processed voltage signal. The charge reconstruction unit is used to reconstruct the total input charge signal based on the charge conservation relationship and the processed voltage signal from any unsaturated and unflooded branch channel.

[0011] Furthermore, the formula for reconstructing the total charge signal is: ; in, Shunt capacitor Branch channel The obtained charge signal; This represents the total number of shunt capacitors. This refers to the total charge signal output by the detector. For the first The output voltage of a charge-sensitive amplifier; Let be the feedback capacitor of the charge-sensitive amplifier; this formula applies to any unsaturated and unflooded branch channel.

[0012] On the other hand, a method for extending the dynamic range of a charge-sensitive amplifier is provided, including: Determine the parameters of the high-voltage isolation shunt capacitor bank and the charge-sensitive amplifier bank; The total charge signal output by the detector is simultaneously injected into the high-voltage isolation shunt capacitor bank. The high-voltage isolation shunt capacitor bank distributes the distributed charge signal to the corresponding charge-sensitive amplifier according to the shunt capacitor ratio. Each charge-sensitive amplifier in the charge-sensitive amplifier group converts the assigned charge signal into a voltage signal; The voltage output and digitization module processes the voltage signals output by each charge-sensitive amplifier and reconstructs the total input charge signal based on the charge conservation relationship.

[0013] Furthermore, determining the parameters of the high-voltage isolation shunt capacitor bank and the charge-sensitive amplifier bank includes: Based on the dynamic range of the input charge signal, select the number, capacitance, and ratio of the shunt capacitors in the high-voltage isolation shunt capacitor bank; Each charge-sensitive amplifier in the charge-sensitive amplifier group uses the same feedback capacitor and has the same conversion gain.

[0014] Furthermore, one shunt capacitor in the high-voltage isolation shunt capacitor bank and the corresponding charge-sensitive amplifier in the charge-sensitive amplifier bank form a corresponding branch channel, and the amount of charge received by each branch channel is: ; satisfy: ; in, Shunt capacitor Branch channel The obtained charge signal; This represents the total number of shunt capacitors. This is the total charge signal output by the detector.

[0015] Furthermore, the voltage output and digitization module processes the voltage signals output by each charge-sensitive amplifier and reconstructs the total input charge signal based on the charge conservation relationship, including: The voltage signals output from each charge-sensitive amplifier are filtered, shaped, peak-protected, and digitized. Based on the dynamic range of the input charge signal and the processed voltage signal, determine the unsaturated and unflooded branch channels; Based on any unsaturated and unflooded branch channel, the total input charge signal is reconstructed according to the charge conservation relationship and the processed voltage signal.

[0016] Furthermore, the formula for reconstructing the total charge signal is: ; in, For the first The output voltage of a charge-sensitive amplifier; is the feedback capacitor of the charge-sensitive amplifier; this formula applies to any unsaturated and unflooded branch channel.

[0017] The present invention has the following advantages due to the adoption of the above technical solutions: 1. Significantly expands the dynamic range: This invention, through a CSA array with the same capacitor shunt and gain, can expand the dynamic range of a single CSA by several orders of magnitude, and theoretically can continue to expand it.

[0018] 2. Maintaining linearity and accuracy: The output voltage of at least one branch channel of this invention is in the optimal quantization range, avoiding saturation and noise overload, and maintaining high linearity across the entire range.

[0019] 3. Lossless signal distribution: This invention uses pure capacitor shunt, which is passive, noiseless, and has no charge loss, thus ensuring measurement accuracy.

[0020] 4. High flexibility: This invention supports selective digitization (reducing resources) and cascaded expansion (refining measurements).

[0021] 5. Simple to implement and low cost: This invention only requires capacitors and standard CSA (same gain), without the need for complex switches or nonlinear components.

[0022] In summary, this invention can be widely applied in the fields of nuclear detection and signal processing technology. Attached Figure Description

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of the device structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a specific case provided by an embodiment of the present invention. Detailed Implementation

[0024] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0025] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0026] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0027] To extend the dynamic range of charge-sensitive amplifiers, several solutions have been proposed in the prior art. However, these solutions either cannot handle high-speed pulse signals, resulting in charge loss during switching, or they sacrifice linearity and measurement accuracy, making them unsuitable for quantitative analysis. They cannot effectively extend the dynamic range of charge-sensitive amplifiers without sacrificing linearity and signal-to-noise ratio. This invention provides a device for extending the dynamic range of a charge-sensitive amplifier, comprising a detector, a high-voltage isolation shunt capacitor bank, a charge-sensitive amplifier bank, and a voltage output and digitization module. The charge-sensitive amplifier bank includes several charge-sensitive amplifiers; the detector outputs a charge signal; the high-voltage isolation shunt capacitor bank distributes the total charge signal output by the detector to the charge-sensitive amplifier bank according to the shunt capacitor ratio and isolates the high voltage at the detector end; each charge-sensitive amplifier in the charge-sensitive amplifier bank has the same conversion gain and converts the distributed charge signal into a voltage signal; the voltage output and digitization module processes the voltage signal and reconstructs the input total charge signal based on the charge conservation relationship. This invention employs a pure capacitor passive shunt, resulting in no charge loss and no noise introduction. While maintaining high linearity and signal-to-noise ratio, it effectively expands the input dynamic range of the charge-sensitive amplifier, making it suitable for systems requiring effective processing of wide dynamic range charge quantities, such as particle detection, experimental nuclear physics, and medical imaging.

[0028] Example 1 like Figure 1 As shown, this embodiment provides a device for extending the dynamic range of a charge-sensitive amplifier, including a detector 1, a high-voltage isolation shunt capacitor bank 2, a charge-sensitive amplifier bank 3, and a voltage output and digitization module 4, wherein the charge-sensitive amplifier bank 3 includes several charge-sensitive amplifiers.

[0029] The output terminal of detector 1 is connected to the input terminal of high-voltage isolation shunt capacitor group 2. Detector 1 is used to output a charge signal with a wide dynamic range. High-voltage isolation shunt capacitor group 2 is used to distribute the total charge signal output by detector 1 to charge sensitive amplifier group 3 according to the shunt capacitor ratio and isolate the high voltage at the detector 1 terminal.

[0030] The output terminal of the high-voltage isolation shunt capacitor group 2 is connected to the input terminal of the corresponding charge-sensitive amplifier in the charge-sensitive amplifier group 3. Each charge-sensitive amplifier has the same conversion gain. The charge-sensitive amplifier is used to convert the allocated charge signal into a voltage signal.

[0031] The output terminals of each charge-sensitive amplifier are connected to the voltage output and the input terminal of the digitization module 4, respectively. The voltage output and digitization module 4 are used to filter, shape, peak protect, and digitize the voltage signal and then reconstruct the total input charge signal according to the charge conservation relationship.

[0032] In a preferred embodiment, the high-voltage isolation shunt capacitor bank 2 includes several shunt capacitors connected in parallel. One end of each of the parallel shunt capacitors is connected to the output terminal of the detector 1, and the other end of each of the parallel shunt capacitors is connected to the input terminal of the corresponding charge-sensitive amplifier in the charge-sensitive amplifier bank 3. For example, as shown in Figure 2, the high-voltage isolation shunt capacitor bank 2 includes three shunt capacitors connected in parallel. Shunt capacitor The other end is connected to the input terminal of the charge-sensitive amplifier CSA1, and the shunt capacitor... The other end is connected to the input terminal of the charge-sensitive amplifier CSA2, and the shunt capacitor... The other end is connected to the input terminal of the charge-sensitive amplifier CSA3.

[0033] Specifically, all shunt capacitors in the high-voltage isolation shunt capacitor group 2 should meet the bias withstand voltage requirements of detector 1.

[0034] Specifically, the large shunt capacitor (e.g., 10nF) in the high-voltage isolation shunt capacitor group 2 is selected as a low dielectric absorption, high stability capacitor (e.g., C0G / NP0).

[0035] In a preferred embodiment, the number of charge-sensitive amplifiers in charge-sensitive amplifier group 3 is the same as the number of shunt capacitors in high-voltage isolation shunt capacitor group 2. For example... Figure 2 As shown, each charge-sensitive amplifier includes an operational amplifier. Feedback capacitor and bleed resistor Each operational amplifier The inverting input terminal is connected to the corresponding shunt capacitor and feedback capacitor respectively. and bleed resistor One end, each operational amplifier The non-inverting input terminals of each operational amplifier are grounded. Feedback capacitors are connected in parallel to the output terminals respectively. and bleed resistor The other end is the voltage output and the input of the digital module 4.

[0036] Specifically, all feedback capacitors Precise matching (i.e., capacitors should be as similar in size as possible, with capacitance values ​​that are infinitely close to equal) is required to ensure consistent conversion gain.

[0037] Specifically, a shunt capacitor in the high-voltage isolation shunt capacitor group 2 and a corresponding charge-sensitive amplifier in the charge-sensitive amplifier group 3 form a corresponding branch channel.

[0038] In a preferred embodiment, the voltage output and digitization module 4 includes a signal processing unit, a branch channel selection unit, and a charge reconstruction unit.

[0039] The signal processing unit is used to filter, shape, peak protect, and digitize the voltage signal to obtain the processed voltage signal.

[0040] The branch channel selection unit is used to determine unsaturated (i.e., signals that have not been clipped, generally lower than the maximum value of the device output signal) and unsubmerged (i.e., signals that have not been submerged by noise, generally greater than the noise voltage) branch channels based on the dynamic range of the input charge signal and the processed voltage signal.

[0041] The charge reconstruction unit is used to reconstruct the total input charge signal based on the charge conservation relationship and the processed voltage signal from any unsaturated and unflooded branch channel.

[0042] like Figure 2 As shown, embodiments of the present invention extend the dynamic range to six orders of magnitude (e.g., input charge from 20 fC to 20 nC, i.e., 1 × 10⁻⁶). 6 Taking a three-way parallel processing structure as an example, three shunt capacitors and three charge-sensitive amplifiers (CSA1, CSA2, and CSA3) with the same conversion gain are used. Those skilled in the art, based on the description of this embodiment, can easily extend it to more channels or different dynamic range requirements.

[0043] Example 2 This embodiment provides a method for extending the dynamic range of a charge-sensitive amplifier, including the following steps: 1) Determine the parameters of high-voltage isolation shunt capacitor group 2 and charge-sensitive amplifier group 3, specifically: 1.1) Select the number, capacitance and ratio of shunt capacitors in high-voltage isolation shunt capacitor group 2 according to the dynamic range of the input charge signal.

[0044] Specifically, the value of the shunt capacitor must take into account the actual parasitic capacitance, noise, and circuit feasibility.

[0045] Specifically, the selection of the number of shunt capacitors depends on the size of the dynamic range of the input charge: covering four orders of magnitude (e.g., 1:10). 4 ): Select 2 capacitors, with a capacitance ratio of approximately 1:100; covering 6 orders of magnitude (e.g., 1:10). 6 ): Select 3 capacitors, with a capacitance ratio of approximately 1:100:10000, and so on.

[0046] 1.2) In charge-sensitive amplifier group 3, each charge-sensitive amplifier uses the same feedback capacitor, therefore the conversion gain... same.

[0047] 2) Total charge signal output by detector 1 Simultaneously, high-voltage isolation shunt capacitor group 2 is injected, and the current is distributed to each shunt capacitor connected in parallel in high-voltage isolation shunt capacitor group 2 according to the shunt capacitor ratio. Each shunt capacitor The assigned charge signal is sent to the corresponding charge-sensitive amplifier.

[0048] Specifically, the amount of charge received by each branch channel is: (1) satisfy: (2) in, Shunt capacitor Branch channel The obtained charge signal; This represents the total number of shunt capacitors. Representing from 1 to , for .

[0049] 3) Each charge-sensitive amplifier in charge-sensitive amplifier group 3 converts the assigned charge signal into a voltage signal.

[0050] Specifically, the output voltage of each charge-sensitive amplifier in charge-sensitive amplifier group 3 for: (3) in, For the first The output voltage of each charge-sensitive amplifier. It can be seen that the output voltage of each branch channel of charge-sensitive amplifier group 3 is related to the shunt capacitance of the corresponding branch channel. Proportional.

[0051] because ∝ By appropriately selecting the shunt capacitor values ​​(e.g., differing by a factor of 100), the following can be achieved: For extremely small input charges, only the output voltage of the large capacitor branch channel is within the detectable range, while the output voltage of the small capacitor branch channel is too small and overwhelmed by noise; for extremely large input charges, only the output voltage of the small capacitor branch channel is within the detectable range, while the output voltage of the large capacitor branch channel is too large and leads to saturation; for intermediate ranges, at least one branch channel's output voltage is within the ADC's optimal quantization range. Therefore, the total dynamic range is segmented and covered by multiple branch channels, significantly expanding the overall equivalent dynamic range.

[0052] 4) The voltage output and digitization module 4 processes the voltage signals output by each charge-sensitive amplifier and reconstructs the total input charge signal based on the charge conservation relationship. Specifically: 4.1) The voltage signals output by each charge-sensitive amplifier are filtered, shaped, peak-protected, and digitized.

[0053] 4.2) Based on the dynamic range of the input charge signal and the processed voltage signal, determine the unsaturated (i.e., the signal that has not been clipped, which is generally lower than the maximum value of the device output signal) and unsubmerged (i.e., the signal that has not been submerged by noise, which is generally greater than the noise voltage) branch channels.

[0054] 4.3) Based on any unsaturated and unsubmerged branch channel, reconstruct the total input charge signal according to the charge conservation relationship and the processed voltage signal.

[0055] The formula for reconstructing the total charge signal is: (4) In practical use, it is recommended to prioritize the channel whose output voltage is within the optimal range of the ADC (such as 10% to 90% of the full scale) for reconstruction. Alternatively, the results from multiple channels can be merged to improve accuracy.

[0056] The following is based on Figure 2 The structure shown is a detailed description of the method for extending the dynamic range of the charge-sensitive amplifier according to a specific embodiment of the present invention: 1) Determine the parameters of the capacitors in high-voltage isolation shunt capacitor group 2 and charge-sensitive amplifier group 3: Based on the dynamic range of the input charge (20fC~20nC, i.e., 6 orders of magnitude), the shunt capacitor ratio is selected as 1:100:10000. =1pF, =100pF, =10 nF.

[0057] The three charge-sensitive amplifiers use the same feedback capacitor. =1pF, then the conversion gain Both are 1V / pC.

[0058] The total parallel capacitance of high-voltage isolation shunt capacitor bank 2 and charge-sensitive amplifier bank 3 is =1pF + 100pF + 10000pF = 10101pF.

[0059] 2) The total charge signal output by detector 1 is simultaneously injected into high-voltage isolation shunt capacitor bank 2, and distributed to each shunt capacitor connected in parallel in high-voltage isolation shunt capacitor bank 2 according to the shunt capacitor ratio: Figure 2 The charge signals distributed in the three branch channels are as follows: , , .

[0060] 3) Each charge-sensitive amplifier in charge-sensitive amplifier group 3 converts the assigned charge signal into a voltage signal: Figure 2 The voltage signals output from the three branch channels are as follows: , , .

[0061] 4) Voltage output and digitization module 4 processes the voltage signals output by each charge-sensitive amplifier and reconstructs the total input charge signal based on the charge conservation relationship: 4.1) The voltage signals output by each charge-sensitive amplifier are filtered, shaped, peak-protected, and digitized.

[0062] 4.2) Based on the dynamic range of the input charge signal and the processed voltage signal, determine the unsaturated and unflooded branch channels. The noise voltage is typically around 10mV, and the operating voltage of the devices is generally 5V or 12V. Minimum signal:

[0063] (Less than the noise voltage, thus being overwhelmed by noise); (Voltage less than the noise level is overwhelmed by noise); (Greater than noise voltage, detectable); At this time, a branch capacitor is selected. The corresponding branch channel 3 reconstructs the total charge.

[0064] Maximum signal:

[0065] (Greater than noise voltage, detectable); (Theoretical value; the output voltage exceeds the device's operating voltage, but in reality, it is already saturated.) (Theoretical value, actual saturation) At this time, a branch capacitor is selected. The corresponding branch channel 1 reconstructs the total charge. If a larger shunt ratio is used, the output of branch channel 3 may also be moderate, but in this embodiment, branch channel 1 has already met the requirements.

[0066] Intermediate signal:

[0067] (Submerged by noise); (Detectable); (Theoretical value, actual saturation) At this time, the branch capacitor The corresponding branch channel 2 output is optimal, so branch channel 2 is selected to rebuild the total charge.

[0068] Therefore, it can be seen that under different input charge levels, the output voltage of one branch channel will always be within the optimal quantization range of the ADC (e.g., 0.01 mV to 5 V), while the output voltage of the other channels will either be saturated or too low. By selecting the properly functioning branch channel and using the reconstruction formula, the full range of input charge can be accurately measured.

[0069] 4.3) Based on any unsaturated and unflooded channel, reconstruct the total input charge signal according to the charge conservation relationship and the processed voltage signal: Taking branch channel 2 as an example (assuming its output voltage) (Unsaturated and with good signal-to-noise ratio), reconstruct the total charge:

[0070] Similarly, it can be rebuilt independently through any branch channel.

[0071] In practical applications, the voltage output and digitization module 4 simultaneously acquires the voltage of three branch channels, automatically determines whether each branch channel is within the effective range (not saturated, not flooded), prioritizes the branch channel with the highest signal-to-noise ratio for reconstruction, or takes a weighted average of multiple branch channels to improve accuracy.

[0072] To make the output voltage closer to the ADC's full-scale range (5V), all shunt capacitors can be reduced proportionally. For example, […]. , , Divide both by 10, then =0.1pF, =10pF, =1nF, the total capacitance becomes 1010.1 pF, and the output voltage increases tenfold accordingly. At this point, with a maximum input voltage of 20nC, ≈3.96V, therefore the scaling ratio should be selected reasonably according to the actual ADC range.

[0073] The above three-branch channel structure is adopted. (Same as above), within the input range of 20fC to 20nC, the output voltage of one branch channel is always in the detectable and unsaturated range, and the measured dynamic range extends to 10. 6 It is twice as fast. Compared with the traditional variable feedback capacitor method, there is no switching noise and charge loss; compared with the logarithmic amplifier, the full-range linearity is better than 0.5%.

[0074] The above embodiments are only used to illustrate the present invention. The structure, connection method and manufacturing process of each component can be varied. All equivalent transformations and improvements made on the basis of the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A device for extending the dynamic range of a charge-sensitive amplifier, characterized in that, It includes a detector, a high-voltage isolation shunt capacitor bank, a charge-sensitive amplifier bank, and a voltage output and digitization module, wherein the charge-sensitive amplifier bank includes several charge-sensitive amplifiers; The detector is used to output charge signals; The high-voltage isolation shunt capacitor bank is used to distribute the total charge signal output by the detector to the charge-sensitive amplifier bank according to the shunt capacitor ratio, and to isolate the high voltage at the detector end; The charge-sensitive amplifiers in the charge-sensitive amplifier group have the same conversion gain, and the charge-sensitive amplifiers are used to convert the allocated charge signal into a voltage signal; The voltage output and digitization module is used to process the voltage signal and reconstruct the input total charge signal based on the charge conservation relationship.

2. The device for extending the dynamic range of a charge-sensitive amplifier as described in claim 1, characterized in that, The high-voltage isolation shunt capacitor bank includes several shunt capacitors connected in parallel; one end of each of the several shunt capacitors connected in parallel is connected to the output terminal of the detector, and the other end of each of the several shunt capacitors connected in parallel is connected to the input terminal of the charge-sensitive amplifier in the charge-sensitive amplifier bank.

3. The device for extending the dynamic range of a charge-sensitive amplifier as described in claim 2, characterized in that, The number of charge-sensitive amplifiers in the charge-sensitive amplifier group is the same as the number of shunt capacitors in the high-voltage isolation shunt capacitor group. One of the shunt capacitors in the high-voltage isolation shunt capacitor group and the corresponding charge-sensitive amplifier in the charge-sensitive amplifier group form a corresponding branch channel.

4. The device for extending the dynamic range of a charge-sensitive amplifier as described in claim 3, characterized in that, The voltage output and digitization module includes: The signal processing unit is used to filter, shape, peak protect, and digitize the voltage signal to obtain the processed voltage signal. The branch channel selection unit is used to determine the unsaturated and unflooded branch channels based on the dynamic range of the input charge signal and the processed voltage signal. The charge reconstruction unit is used to reconstruct the total input charge signal based on the charge conservation relationship and the processed voltage signal from any unsaturated and unflooded branch channel.

5. The device for extending the dynamic range of a charge-sensitive amplifier as described in claim 4, characterized in that, The formula for reconstructing the total charge signal is: ； in, Shunt capacitor Branch channel The obtained charge signal; This represents the total number of shunt capacitors. This refers to the total charge signal output by the detector. For the first The output voltage of a charge-sensitive amplifier; Let be the feedback capacitor of the charge-sensitive amplifier; this formula applies to any unsaturated and unflooded branch channel.

6. A method for extending the dynamic range of a charge-sensitive amplifier, characterized in that, include: Determine the parameters of the high-voltage isolation shunt capacitor bank and the charge-sensitive amplifier bank; The total charge signal output by the detector is simultaneously injected into the high-voltage isolation shunt capacitor bank. The high-voltage isolation shunt capacitor bank distributes the distributed charge signal to the corresponding charge-sensitive amplifier according to the shunt capacitor ratio. Each charge-sensitive amplifier in the charge-sensitive amplifier group converts the assigned charge signal into a voltage signal; The voltage output and digitization module processes the voltage signals output by each charge-sensitive amplifier and reconstructs the total input charge signal based on the charge conservation relationship.

7. The method for extending the dynamic range of a charge-sensitive amplifier as described in claim 6, characterized in that, The determination of the parameters for the high-voltage isolation shunt capacitor bank and the charge-sensitive amplifier bank includes: Based on the dynamic range of the input charge signal, select the number, capacitance, and ratio of the shunt capacitors in the high-voltage isolation shunt capacitor bank; Each charge-sensitive amplifier in the charge-sensitive amplifier group uses the same feedback capacitor and has the same conversion gain.

8. The method for extending the dynamic range of a charge-sensitive amplifier as described in claim 6, characterized in that, One shunt capacitor in the high-voltage isolation shunt capacitor bank and the corresponding charge-sensitive amplifier in the charge-sensitive amplifier bank form a corresponding branch channel. The amount of charge received by each branch channel is: ； satisfy: ； in, Shunt capacitor Branch channel The obtained charge signal; This represents the total number of shunt capacitors. This is the total charge signal output by the detector.

9. The method for extending the dynamic range of a charge-sensitive amplifier as described in claim 8, characterized in that, The voltage output and digitization module processes the voltage signals output by each charge-sensitive amplifier and reconstructs the total input charge signal based on the charge conservation relationship, including: The voltage signals output from each charge-sensitive amplifier are filtered, shaped, peak-protected, and digitized. Based on the dynamic range of the input charge signal and the processed voltage signal, determine the unsaturated and unflooded branch channels; Based on any unsaturated and unflooded branch channel, the total input charge signal is reconstructed according to the charge conservation relationship and the processed voltage signal.

10. The method for extending the dynamic range of a charge-sensitive amplifier as described in claim 9, characterized in that, The formula for reconstructing the total charge signal is: ； in, For the first The output voltage of a charge-sensitive amplifier; is the feedback capacitor of the charge-sensitive amplifier; this formula applies to any unsaturated and unflooded branch channel.

Images