Signal calibration conditioning device for Raman spectrometer

Abstract

The utility model provides a signal calibration conditioning device for a Raman spectrometer, which comprises a control core, a reference voltage module, a CCD (Charge Coupled Device) driving and signal acquisition module, a DAC (Digital-to-Analog Converter) buffer dark current suppression module and a programmable gain adjusting module, and is characterized in that the control core is connected with the DAC buffer dark current suppression module; the DAC buffer dark current suppression module is connected with the programmable gain adjustment module, the CCD driving and signal acquisition module is connected with the control core and the programmable gain adjustment module, and the reference voltage module is connected with the CCD driving and signal acquisition module, the programmable gain adjustment module, the control core and the DAC buffer dark current suppression module. The DAC buffer dark current suppression module buffers the output voltage of the control core to suppress the dark current, and provides a substrate voltage to offset the dark current noise of the CCD sensor; the programmable gain adjustment module realizes adjustment of gain multiples, adapts to a quantum efficiency difference CCD sensor, and reduces multi-machine signal intensity deviation.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of spectrum analysis technology, especially a kind of for Raman spectrometer signal calibration conditioning device. BACKGROUND

[0002] Raman spectrometer is the core equipment of myocardial infarction rapid screening, realizes pathological analysis by detecting the Raman scattering spectrum of biomarker such as blood myocilin. In clinical practice, multiple devices need to work cooperatively, but due to the inherent tolerance of semiconductor technology (quantum efficiency ±10%-20%, dark current fluctuation ±30%) of CCD sensor, the signal acquisition of different devices to the same standard sample is significantly different. The prior art has the following shortcomings: first, there is no targeted dark current suppression hardware, and μV level Raman signal is easily disturbed by noise;Second, the gain adjustment accuracy is insufficient, and it cannot adapt to CCD sensors with different tolerances. UTILITY MODEL CONTENT

[0003] To solve the above problems, the purpose of the utility model is to provide a kind of for Raman spectrometer signal calibration conditioning device.

[0004] The utility model adopts the following method to realize: a kind of for Raman spectrometer signal calibration conditioning device, including control core and reference voltage module, and CCD drive and signal acquisition module, still including DAC buffer dark current suppression module, programmable gain adjustment module, the control core is connected with the DAC buffer dark current suppression module, the DAC buffer dark current suppression module is connected with the programmable gain adjustment module, the CCD drive and signal acquisition module are connected with the control core and the programmable gain adjustment module, the reference voltage module connects the CCD drive and signal acquisition module, the programmable gain adjustment module, the control core and the DAC buffer dark current suppression module.

[0005] Preferably, the DAC buffer dark current suppression module includes voltage follower and DAC_buffer node, the DAC_buffer node is connected with control core, the DAC_buffer node is also connected with the voltage follower, the output end of the voltage follower is connected with the programmable gain adjustment module, to output substrate voltage to the programmable gain adjustment module, for offsetting the fixed dark current noise of the CCD drive and signal acquisition module.

[0006] Preferably, the voltage follower is first operational amplifier, the same phase input end of the first operational amplifier is connected with the DAC_buffer node, and the opposite phase input end of the first operational amplifier is connected with the output end.

[0007] Preferably, the DAC buffer dark current suppression module further comprises a first filter unit connected between the power supply end and the ground of the first operational amplifier to suppress power supply ripple.

[0008] Preferably, the first filter unit comprises a capacitor C2 and a capacitor C3 connected in parallel between the VDD pin and the ground of the first operational amplifier.

[0009] Preferably, the programmable gain adjustment module comprises a second operational amplifier, a digital potentiometer, the non-inverting input end of the second operational amplifier is connected to the Raman signal output by the CCD driving and signal acquisition module, the inverting input end of the second operational amplifier is connected to the ground through the digital potentiometer, the digital potentiometer is in communication connection with the control core, and the inverting input end of the second operational amplifier is connected to its output end through a resistor R2.

[0010] Preferably, the programmable gain adjustment module further comprises a feedback resistor R3 connected in parallel across the digital potentiometer to limit the maximum adjustable resistance; the digital potentiometer is provided with two, which are a first digital potentiometer and a second digital potentiometer, the nRST pin of the first digital potentiometer is pulled up to VCC through a resistor R2 in parallel, and the nRST pin of the second digital potentiometer is pulled up to VCC through a resistor R3 in parallel.

[0011] Preferably, the CCD driving and signal acquisition module comprises a CCD sensor and an analog-to-digital converter, the video output end of the CCD sensor is connected to the non-inverting input end of the second operational amplifier of the programmable gain adjustment module; the output end of the second operational amplifier is connected to the analog-to-digital converter, and the analog-to-digital converter is connected to the control core.

[0012] Preferably, the CCD driving and signal acquisition module further comprises a filter capacitor C11 and a filter capacitor C18, the filter capacitor C11 is connected between the REFIN pin and the ground of the analog-to-digital converter, and the filter capacitor C18 is connected in parallel to the power supply end of the analog-to-digital converter.

[0013] Preferably, the reference voltage module comprises a reference voltage source, the VOUT pin of the reference voltage source is connected to the REFIN pin of the analog-to-digital converter; the reference voltage module further comprises a 5V power supply and a 3.3V power supply, the 3.3V power supply supplies power to the digital potentiometer and the control core, and the 5V power supply supplies power to the DAC buffer dark current suppression module, the second operational amplifier and the CCD sensor.

[0014] The utility model discloses a kind of signal calibration conditioning devices for Raman spectrometer, compared with prior art, the utility model at least has following technical effects:1. by adding DAC buffer dark current suppression module between control core and programmable gain adjustment module, the output voltage of control core is buffered to suppress dark current, and programmable gain adjustment module is provided with substrate voltage to offset the dark current noise of CCD sensor;And by connecting programmable gain adjustment module between CCD drive and signal acquisition module and control core, programmable gain design realizes the adjustment of gain multiple, can accurately adapt to quantum efficiency difference CCD sensor, CCD drive and signal acquisition module acquire CCD signal after gain adjustment, reduce the signal intensity deviation caused by manufacturing tolerance, to reach the effect of reducing the signal acquisition difference of different machines to same standard sample.2. voltage follower is stabilized to the voltage output of control core, generates accurate substrate voltage to offset the fixed dark current noise of CCD sensor, makes up the defect that prior art lacks specific dark current suppression hardware, removes μV level Raman signal from dark current noise, significantly improves the identifiable degree of weak signal, provides high signal-to-noise ratio original signal for subsequent signal processing.3. by the same-phase amplification circuit of digital potentiometer and operational amplifier, gain is flexibly adjustable, control core can accurately adjust amplification multiple according to quantum efficiency difference of different CCD sensor, solve the problem of insufficient gain adjustment precision of prior art, so that the device can adapt to the error generated by inherent tolerance of CCD sensor semiconductor technology, and the deviation of multi-machine signal acquisition is greatly reduced.4. the signal output of CCD sensor is directly connected to gain adjustment module, and the conditioned signal is transmitted to analog-digital converter, forming "collection-conditioning-conversion" compact link.The structure reduces the transmission distance of signal between modules, reduces the influence of external interference on signal, and the direct connection of analog-digital converter and control core realizes the rapid transmission of collected data, improves the signal processing efficiency of device. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a circuit principle block diagram of the utility model for Raman spectrometer signal calibration conditioning device.

[0016] Figure 2 It is a circuit principle block diagram of the utility model for Raman spectrometer signal calibration conditioning device reference voltage module, CCD drive and signal acquisition module, DAC buffer dark current suppression module, programmable gain adjustment module connection.

[0017] Figure 3 It is the circuit principle diagram of the utility model reference voltage module.

[0018] Figure 4The utility model discloses a CCD drive and signal acquisition module's ADC circuit schematic diagram.

[0019] Figure 5 The utility model discloses a CCD drive and signal acquisition module's CCD sensor circuit schematic diagram.

[0020] Figure 6 The utility model discloses a DAC buffer dark current suppression module's circuit schematic diagram.

[0021] Figure 7 The utility model discloses a programmable gain regulation module's circuit schematic diagram.

[0022] Figure 8 The utility model discloses a control core's FPC interface's circuit schematic diagram.

[0023] Figure number explanation: 30, control core, 40, reference voltage module, 50, CCD drive and signal acquisition module, 60, DAC buffer dark current suppression module, 70, programmable gain regulation module. Specific embodiments

[0024] The utility model will be further explained below with the combination of the drawings and specific embodiments.

[0025] Please refer to Figures 1 to 8The application relates to a Raman spectrometer signal calibration conditioning device, which comprises a control core 30, a reference voltage module 40, a CCD driving and signal acquisition module 50, a DAC buffer dark current suppression module 60 and a programmable gain adjustment module 70; the control core 30 is connected with the DAC buffer dark current suppression module 60; the DAC buffer dark current suppression module 60 is connected with the programmable gain adjustment module 70; the CCD driving and signal acquisition module 50 is connected with the control core 30 and the programmable gain adjustment module 70; and the reference voltage module 40 is connected with the CCD driving and signal acquisition module 50, the programmable gain adjustment module 70, the control core 30 and the DAC buffer dark current suppression module 60. The DAC buffer dark current suppression module 60 is newly added and connected between the control core 30 and the programmable gain adjustment module 70, so that the output voltage of the control core 30 is buffered and dark current is suppressed, and a substrate voltage is provided for the programmable gain adjustment module to offset the dark current noise of a CCD sensor; and the programmable gain adjustment module 70 is connected between the CCD driving and signal acquisition module 50 and the control core 30, so that the programmable gain design realizes gain multiple adjustment and can accurately adapt to a CCD sensor with quantum efficiency difference; the CCD driving and signal acquisition module 50 collects the CCD signal after gain adjustment, reduces the signal intensity deviation caused by manufacturing tolerance, and reduces the signal acquisition difference of different machines for the same standard sample. Preferably, the control core 30 (MCU) can adopt an STM32F407IGT6. The control core 30 has an interface FPC1 and an interface FPC2, as shown in Figure 8 .

[0026] Please refer to Figure 1 , Figure 2 , Figures 6 to 8 . Preferably, the DAC buffer dark current suppression module 60 comprises a voltage follower and a DAC_buffer node; the DAC_buffer node is connected with the control core 30; the DAC_buffer node is also connected with the voltage follower; and the output end of the voltage follower is connected with the programmable gain adjustment module 70 to output a substrate voltage to the programmable gain adjustment module 70 to offset the fixed dark current noise of the CCD driving and signal acquisition module 50. The voltage follower stabilizes the voltage output by the control core 30, generates an accurate substrate voltage to offset the fixed dark current noise of the CCD sensor, compensates for the defect that the prior art lacks targeted dark current suppression hardware, separates the muV-level Raman signal from the dark current noise, significantly improves the recognizability of the weak signal, and provides a high signal-to-noise ratio original signal for subsequent signal processing.

[0027] Please refer to Figure 1 , Figure 2 , Figures 6 to 8, preferably, the voltage follower is a first operational amplifier U2, a non-inverting input terminal of the first operational amplifier U2 is connected to the DAC_buffer node, and an inverting input terminal of the first operational amplifier U2 is directly connected to an output terminal, so as to form a voltage follower. The DAC buffer dark current suppression module 60 further comprises a first filter unit connected between a power supply terminal and a ground terminal of the first operational amplifier U2, so as to suppress power supply ripple. The first filter unit comprises a capacitor C2 and a capacitor C3, which are connected in parallel between a VDD terminal of the first operational amplifier U2 and the ground terminal. Specifically, the DAC_buffer node receives a 0-3.3V adjustable voltage output by an external DAC (a DAC1 pin of the control core 30 (STM32F407IGT6)); the first operational amplifier U2 (LMV321) has a non-inverting input terminal (an A terminal) connected to the DAC_buffer node, and an inverting input terminal (-IN) directly connected to an output terminal (VOUT), so as to form a voltage follower; the first operational amplifier U2 has a VDD terminal connected to +5VA and a VSS terminal connected to the ground; the capacitor C2 and the capacitor C3 are connected in parallel between +5VA and GND, so as to suppress power supply ripple; the base voltage output by the DAC is stably transmitted to an operational amplifier U3 (OPA2350) circuit of a programmable gain adjustment module 70 in a subsequent stage, so as to offset the fixed dark current noise of a CCD sensor (S11639), and when the DAC_buffer outputs 1.5V, the measured dark current noise is less than or equal to 8μV. The DAC buffer dark current suppression module 60 further comprises a capacitor C5, a capacitor C17 and a resistor R1.

[0028] Please refer to Figure 1 、 Figure 2 、 Figure 7 、 Figure 8 , preferably, the programmable gain adjustment module 70 comprises a second operational amplifier U3B and a first digital potentiometer U6 / U7, a non-inverting input terminal of the second operational amplifier U3B is connected to a Raman signal output by the CCD driving and signal collecting module 50, an inverting input terminal of the second operational amplifier U3B is connected to the ground through the first digital potentiometer U6 / U7, the first digital potentiometer U6 / U7 is in communication connection with the control core 30, and the inverting input terminal of the second operational amplifier U3B is connected to an output terminal of the second operational amplifier U3B through a resistor R2. Through the same-phase amplification circuit formed by the first digital potentiometer U6 / U7 and the operational amplifier U3B, the gain is flexibly adjustable, the control core 30 can accurately adjust the amplification multiple according to the quantum efficiency difference of different CCD sensors, and the problem of insufficient gain adjustment precision in the prior art is solved, so that the device can adapt to errors caused by inherent tolerances of CCD sensor semiconductor processes, and the deviation of multi-machine signal collection is greatly reduced.

[0029] Please refer toFigure 1 、 Figure 2 、 Figure 7 、 Figure 8 Preferably, the programmable gain adjustment module 70 further comprises a feedback resistor R3 connected in parallel to both ends of the digital potentiometer to limit the maximum adjustable resistance; the digital potentiometer is provided with two, namely a first digital potentiometer U6 and a second digital potentiometer U7, the nRST pin of the first digital potentiometer U6 is pulled up to VCC through a resistor R2 in parallel, and the nRST pin of the second digital potentiometer U7 is pulled up to VCC through a resistor R3 in parallel. Specifically, the second operational amplifier U3B adopts an OPA2350 operational amplifier, the digital potentiometer adopts an AD5272BRMZ-20-RL7, and there are two (labeled DR_SDA1 / DR_SCL1, DR_SDA2 / DR_SCL2 respectively). The ADDR pin (DR_ADDR1 / DR_ADDR2) of the digital potentiometer AD5272 is connected to GND, the SCL pin (DR_SCL1 / DR_SCL2) and the SDA pin (DR_SDA1 / DR_SDA2) are connected to the I2C interface of the control core 30 (STM32F407IGT6), and the nRST pin (DR_RST1) is connected to +3.3V; the non-inverting input end (+IN) of U3B (OPA2350) is connected to the input of the Raman signal (the video signal output by the CCD sensor), the inverting input end (-IN) is connected to ground through the adjustable resistance of AD5272, and at the same time is connected to the output end (VOUT) through R2 (10K), forming a non-inverting amplification circuit; R3 (10K) is connected in parallel to both ends of the digital potentiometer AD5272 for feedback adjustment to limit the maximum adjustable resistance. By controlling the adjustable resistance value (0-20KΩ) of the digital potentiometer (AD5272) through the control core 30 (STM32F407IGT6), the amplification factor A=1+(R2+AD5272 resistance value) / R3 is realized, the adjustment range is 1-2 times, and the quantum efficiency difference of the CCD sensor (S11639) CCD is adapted, which is adjusted to 1.3 times in weak signal and to 1.1 times in strong signal. The programmable gain adjustment module 70 further comprises an operational amplifier U3A, a resistor R4, a resistor R5, a resistor R6, a capacitor C6, a capacitor C7, and a capacitor C10.

[0030] Please refer to Figure 1 、 Figure 2 、 Figure 4 、 Figure 5, preferably, the CCD driving and signal acquisition module 50 comprises a CCD sensor U5 and an analog-to-digital converter U4, a video output end of the CCD sensor U5 is connected to a non-inverting input end of a second operational amplifier U3B of a programmable gain adjustment module 70; an output end of the second operational amplifier U3B is connected to the analog-to-digital converter U4, and the analog-to-digital converter U4 is connected to the control core 30. The CCD driving and signal acquisition module 50 further comprises a filter capacitor C11 and a filter capacitor C18, the filter capacitor C11 is connected between a REFIN pin of the analog-to-digital converter U4 and the ground, and the filter capacitor C18 is connected in parallel to a power supply end of the analog-to-digital converter U4. Specifically, a CLK pin (CCD_CLK) of the CCD sensor (S11639) is connected to an external clock signal through an R14, a ST pin (CCD_ST) is connected to a GPIO of the control core 30 (STM32F407IGT6) through an R16, an EOS pin, a Trig pin and a Vlcp pin are respectively connected to corresponding control signals, and row-by-row scanning is realized. Signal output: a Video pin (13 pin) of the CCD sensor U5 (S11639) is connected to a signal input of the second operational amplifier U3B (OPA2350), and after conditioning, the signal is output to the analog-to-digital converter U4 (ADS8319); a CONVST pin (6 pin) of the U4 is connected to a SDO (ADC_DO) of the control core 30 (STM32F407IGT6) through an R13, SCLK (ADC_CLK) and SDI (ADC_DI) pins are respectively connected to an SPI interface through R8-R10, and a REFIN pin is connected to a reference voltage source U1 (REF3025AIDBZR (2.5V reference voltage)); C11 is connected in parallel between the REFIN and the GND of the analog-to-digital converter U4 (ADS8319), and C18 is connected in parallel to a power supply end of the CCD sensor U1 (S11639), so as to reduce acquisition noise. The CCD sensor U1 (S11639) receives a Raman light signal and converts it into an electrical signal, which is conditioned by the second operational amplifier U3B (OPA2350) and then collected by the analog-to-digital converter U4 (ADS8319) at a high precision of 16 bits (resolution 0.15mV), so as to ensure that the signal is not distorted. The CCD driving and signal acquisition module 50 further comprises capacitors C12, C13, C14 and C15, resistors R11, R14 and R16, and further comprises capacitors C8, C9, resistors R8, R10, R12, R13, R9, R15 and R17.

[0031] Please refer to Figure 1 、 Figure 2 、 Figure 3, preferably, the reference voltage module 40 includes a reference voltage source U1, the VOUT pin of the reference voltage source is connected with the REFIN pin of the analog-digital converter U4;The reference voltage module 40 further includes a 5V power supply and a 3.3V power supply, the 3.3V power supply is used to supply power for the digital potentiometer, the control core 30 is supplied with power, and the 5V power supply is used to supply power for the DAC buffer dark current suppression module 60, the second operational amplifier U3B and the CCD sensor.Specifically, the VOUT pin of the reference voltage source (REF3025A) is connected with the REFIN pin of the analog-digital converter U4 (ADS8319), a precise 2.5V reference is provided, and the ADC acquisition accuracy is ensured;+3.3V is used to supply power for the first digital potentiometer U6\U7 (AD5272), the control core 30 (STM32F407IGT6), +5VA is used to supply power for the first operational amplifier U2 (LMV321), the operational amplifier U3 (OPA2350) and the CCD sensor (S11639);Each power supply terminal is connected with a ceramic capacitor and a tantalum capacitor in parallel to suppress the ripple;Stable and low-noise power supply is provided for each module to avoid signal deviation caused by voltage fluctuation.The reference voltage module 40 further includes a capacitor C1 and a capacitor C4.

[0032] The utility model has the following working principle:

[0033] Dark current suppression: the control core 30 (STM32F407IGT6) exports 1.5VDAC voltage to DAC_buffer node, provides the base voltage for the second operational amplifier U3B (OPA2350) after voltage follower of operational amplifier U2 (LMV321), offsets the dark current noise of CCD sensor (S11639), and analog-digital converter U4 (ADS8319) monitors noise voltage≤8muV;

[0034] CCD drive: the control core 30 (STM32F407IGT6) controls the working mode of CCD sensor (S11639) to be line-by-line scanning through CCD_CLK (R14), CCD_ST (R16) pin, and acetonitrile Raman signal is collected;

[0035] Gain adjustment: the Video signal of CCD sensor (S11639) is input to the second operational amplifier U3B and is adjusted to the gain of digital potentiometer (AD5272) by the control core 30, if Video signal AD value is less than 100, the gain is increased to 1.3 times;If AD value is greater than 3000, the gain is reduced to 1.1 times;

[0036] Signal acquisition: the conditioned signal is input into the analog-to-digital converter U4 (ADS8319), and the control core 30 sends a CONVST signal to trigger acquisition, and 16-bit AD data is read through SPI for subsequent pixel-point-wave number polynomial fitting calibration.

[0037] Test:

[0038] Dark current suppression debugging: test conditions: turn off the laser, the CCD sensor is not illuminated, the control core 30 outputs a DAC voltage gradient (0V, 1V, 1.5V, 2V, 3V); then the output voltage of the second operational amplifier U3B is collected by the analog-to-digital converter U4, and the dark current noise value is recorded - when the DAC voltage is 1.5V, the noise voltage is stable at 6.5μV≤8μV, and the voltage is determined as the optimal base voltage, which is stored in the Flash of the STM32F407IGT6.

[0039] Gain adjustment and signal acquisition verification: analog signal input: input a 10μV-50μV gradient analog signal (analog acetonitrile Raman signal) into the same phase input end of the second operational amplifier U3B.

[0040] Gain test: the control core 30 controls the first digital potentiometer U6\U7 to adjust the gain to 1.1 times, 1.2 times, and 1.3 times, and the analog-to-digital converter U4 collects the output signal: 10μV signal→1.1 times gain output 11.0μV±0.5μV, 1.3 times gain output 13.2μV±0.5μV; 50μV signal→1.2 times gain output 60.1μV±0.5μV, without oversaturation (ADS8319 2.5V reference, upper limit of range corresponds to 15625μV).

[0041] Distortion detection: measure the total harmonic distortion (THD) of the signal under each gain ≤0.8%, which meets the linear amplification requirement.

[0042] Clinical scene integration test: connect the device to the Raman spectrometer, and collect acetonitrile standard spectrum in the emergency room environment (15-35℃, 30%-80%RH). The results verify that: the CCD sensor collects acetonitrile 4 characteristic peaks (378cm - ¹、918cm - ¹、1374cm - ¹、2252cm - ¹) corresponding to pixel point signals, the AD value collected by the analog-to-digital converter U4 has a relative standard deviation (RSD) of 1.2%, and the dark current noise is ≤7μV, which meets the multi-machine calibration hardware requirement.

[0043] It should be noted that: first, in the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be broadly understood, which can be mechanical connection or electrical connection, or the communication between two elements, or direct connection, "up", "down", "left", "right" and the like are only used to indicate the relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may change.

[0044] Secondly: the utility model discloses the embodiment in the drawing, only relate to the structure involved in the embodiment of the present disclosure, other structures can refer to the usual design, under the condition of not conflicting, the same embodiment and different embodiments of the utility model can be combined with each other.

[0045] Finally, the above-mentioned is only the preferred embodiment of the utility model, the protection scope of the utility model is not only limited to the above-mentioned embodiment, and all technical solutions under the idea of the utility model belong to the protection scope of the utility model.

[0046] It should be noted that, for ordinary skilled persons in the art, without departing from the principles of the utility model, some improvements and refinements, these improvements and refinements should also be considered as the protection scope of the utility model.

Claims

1. A signal calibration conditioning device for Raman spectrometer, comprising a control core and a reference voltage module, and a CCD drive and signal acquisition module, characterized in that: The control core is connected with the DAC buffer dark current suppression module, the DAC buffer dark current suppression module is connected with the programmable gain adjustment module, the CCD drive and signal acquisition module is connected with the control core and the programmable gain adjustment module, and the reference voltage module is connected with the CCD drive and signal acquisition module, the programmable gain adjustment module, the control core and the DAC buffer dark current suppression module.

2. A signal conditioning device for a Raman spectrometer according to claim 1, characterized in that: The DAC buffer dark current suppression module comprises a voltage follower and a DAC_buffer node, the DAC_buffer node is connected with the control core, the DAC_buffer node is also connected with the voltage follower, and the output end of the voltage follower is connected with the programmable gain adjustment module to output a base voltage to the programmable gain adjustment module for offsetting the fixed dark current noise of the CCD drive and signal acquisition module.

3. A signal conditioning device for a Raman spectrometer according to claim 2, wherein: The voltage follower is a first operational amplifier, the non-inverting input end of the first operational amplifier is connected with the DAC_buffer node, and the inverting input end of the first operational amplifier is connected with the output end.

4. A signal conditioning device for a Raman spectrometer according to claim 3, wherein: The DAC buffer dark current suppression module further comprises a first filter unit connected between the power supply end and the ground of the first operational amplifier to suppress the power supply ripple.

5. A signal conditioning device for a Raman spectrometer according to claim 4, wherein: The first filter unit comprises a capacitor C2 and a capacitor C3, and the capacitor C2 and the capacitor C3 are connected in parallel between the VDD pin and the ground of the first operational amplifier.

6. A signal conditioning device for a Raman spectrometer according to claim 1, wherein: The programmable gain adjustment module comprises a second operational amplifier and a digital potentiometer, the non-inverting input end of the second operational amplifier is connected with the Raman signal output by the CCD drive and signal acquisition module, the inverting input end of the second operational amplifier is connected with the ground through the digital potentiometer, the digital potentiometer is in communication connection with the control core, and the inverting input end of the second operational amplifier is connected with the output end through a resistor R2.

7. A signal conditioning device for a Raman spectrometer according to claim 6, wherein: The programmable gain adjustment module further comprises a feedback resistor R3 connected in parallel across the digital potentiometer to limit the maximum adjustable resistance; the digital potentiometer is provided with two first and second digital potentiometers, the nRST pin of the first digital potentiometer is connected in parallel with the resistor R2 and pulled up to VCC, and the nRST pin of the second digital potentiometer is connected in parallel with the resistor R3 and pulled up to VCC.

8. A signal conditioning device for a Raman spectrometer according to claim 6, characterized in that: The CCD drive and signal acquisition module comprises a CCD sensor and an analog-to-digital converter, the video output end of the CCD sensor is connected with the non-inverting input end of the second operational amplifier of the programmable gain adjustment module, the output end of the second operational amplifier is connected with the analog-to-digital converter, and the analog-to-digital converter is connected with the control core.

9. A signal conditioning device for a Raman spectrometer according to claim 8, wherein: The CCD drive and signal acquisition module further comprises a filter capacitor C11 and a filter capacitor C18, the filter capacitor C11 is connected between the REFIN pin and the ground of the analog-to-digital converter, and the filter capacitor C18 is connected in parallel with the power supply end of the analog-to-digital converter.

10. A signal conditioning device for a Raman spectrometer according to claim 8, wherein: The reference voltage module comprises a reference voltage source, a VOUT pin of the reference voltage source is connected to a REFIN pin of the analog-to-digital converter; the reference voltage module further comprises a 5V power supply and a 3.3V power supply, the 3.3V power supply is used for supplying power for the digital potentiometer and the control core, and the 5V power supply is used for supplying power for the DAC buffer dark current suppression module, the second operational amplifier and the CCD sensor.

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