Electrochemical workstation electrode voltage modulation circuit based on LMP91000 chip

Abstract

The application provides an electrode voltage modulation circuit of an electrochemical workstation based on an LMP91000 chip, which adjusts the reference voltage of an electrochemical sensor interface IC, utilizes a DAC output signal and combines a proportional adder for modulation to generate an accurate voltage; wherein a microprocessor sends a voltage adjustment signal to the electrochemical sensor interface IC and the DAC through an I2C bus and an SPI protocol, the microprocessor compares the VLMP value with a target voltage by gradually increasing the VLMP value, ensures that the voltage is within a set error range, and when the error exceeds the set range, the microprocessor automatically increases the Vref reference voltage and readjusts the VLMP value. The method provided by the application realizes a voltage output system with high precision, high flexibility, a wide voltage range and accurate error control. Not only the adjustability and stability of the system are enhanced, but also the hardware platform can adapt to more complex and fine application requirements.

Description

Technical Field

[0001] This application belongs to the field of electrochemical workstation technology, specifically relating to an electrode voltage modulation circuit for an electrochemical workstation based on the LMP91000 chip. Background Technology

[0002] Existing electrochemical detection workstations occasionally exhibit abnormal detection voltages or currents, which, due to the inability to detect them promptly, affect the accuracy and reliability of the test results. Furthermore, the detection process in electrochemical workstations requires converting difficult-to-acquire current signals into voltage signals. However, due to the wide variety of chemical solutions being tested, the resulting current signals and interference noise are diverse. Current technologies, lacking targeted current / voltage signal conversion and filtering measures, inevitably compromise the accuracy and reliability of the test results. Utility Model Content

[0003] To address the shortcomings of the prior art, this application provides an electrode voltage modulation circuit for an electrochemical workstation based on the LMP91000 chip. By adjusting the reference voltage of the electrochemical sensor interface IC, the circuit utilizes the DAC output signal and combines it with a proportional adder for modulation to generate a precise voltage.

[0004] In a preferred first aspect, this application proposes an electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip, comprising: an electrochemical sensor interface IC, a microprocessor, a DAC, and a proportional adder;

[0005] The electrochemical sensor interface IC is connected to a chemical electrode at one end and to a microprocessor at the other end.

[0006] The other end of the microprocessor is connected to the DAC;

[0007] The DAC is connected to the positive input of the proportional adder; the negative output of the proportional adder is connected to the VREF port of the electrochemical sensor interface IC.

[0008] The circuit design effectively integrates the electrochemical sensor interface IC, microprocessor, DAC, and proportional adder, simplifying and facilitating system design. Through precise adjustment of the VREF port, flexible signal control, enhanced signal processing capabilities, and low power consumption, the performance and reliability of the electrochemical workstation system are improved. Furthermore, the combination of the DAC (digital-to-analog converter) and proportional adder enables precise voltage regulation. The negative feedback control of the proportional adder helps maintain a stable operating environment for the electrochemical sensor, thereby improving measurement accuracy. Simultaneously, this integrated design effectively reduces hardware complexity and lowers system costs.

[0009] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes a connection between the microprocessor and the electrochemical sensor interface IC via an I2C bus.

[0010] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes a connection between the microprocessor and the DAC via SPI.

[0011] Preferably, the electrode voltage modulation circuit of the electrochemical workstation based on the LMP91000 chip described in this application includes initializing the reference voltage of the microprocessor to the lowest Vref each time it is powered on.

[0012] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes initializing the reference voltage of the electrochemical sensor interface IC to 0% of the lowest Vref each time it is powered on.

[0013] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes the microprocessor simultaneously sending voltage signals to the electrochemical sensor interface IC and DAC.

[0014] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes the DAC signal range from 0 to the maximum value of the electrochemical electrode voltage.

[0015] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes an electrochemical sensor interface IC that supports 12 levels of electrochemical electrode voltage, namely 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, and 22% of the reference voltage.

[0016] Preferably, this application may also provide an electrochemical workstation, which includes a power control circuit as described in the first aspect above.

[0017] The power control circuit provided in this application has technical advantages such as high-precision voltage control, rich voltage adjustment options, flexible data transmission methods, and strong system stability. By combining multiple modules such as microprocessors, DACs, and proportional adders into a unified control system, it simplifies the system design and integration process, reduces the number of hardware modules, lowers system costs, and improves the overall system stability and reliability, while effectively enhancing the accuracy and reliability of the electrochemical workstation.

[0018] Compared with the prior art, the advantages of this application are as follows:

[0019] This application provides an electrode voltage modulation circuit for an electrochemical workstation based on the LMP91000 chip. By adjusting the reference voltage of the electrochemical sensor interface IC, the circuit utilizes the DAC output signal and a proportional adder for modulation to generate a precise voltage. The microprocessor sends voltage adjustment signals to the electrochemical sensor interface IC and the DAC via the I2C bus and SPI protocol. The microprocessor gradually increases the VLMP value and compares it with the target voltage to ensure the voltage remains within a set error range. When the error exceeds the set range, the microprocessor automatically increases the Vref reference voltage and readjusts the VLMP value. The electrochemical workstation proposed in this application achieves a high-precision, highly flexible, wide-range voltage output system with precise error control. This not only enhances the system's adjustability and stability but also enables the hardware platform to adapt to more complex and sophisticated application requirements. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the electrode voltage modulation circuit of an electrochemical workstation based on the LMP91000 chip in one embodiment.

[0021] Figure 2 This is a circuit diagram of an electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip in one embodiment.

[0022] Figure 3 This is a flowchart of an electrode voltage modulation circuit algorithm for an electrochemical workstation based on the LMP91000 chip, as shown in one embodiment.

[0023] Figure 4 This is a schematic diagram of the electrode operation in an electrolytic cell according to one embodiment.

[0024] Figure 5 This is an electrode kit as described in one embodiment. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] like Figure 1-2 As shown, this application proposes an electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip, which includes: an electrochemical sensor interface IC, a microprocessor, a DAC, and a proportional adder.

[0027] The electrochemical sensor interface IC is connected to a chemical electrode at one end and to a microprocessor at the other end.

[0028] The other end of the microprocessor is connected to the DAC;

[0029] The DAC is connected to the positive input of the proportional adder; the negative output of the proportional adder is connected to the VREF port of the electrochemical sensor interface IC.

[0030] The electrochemical sensor interface IC can optionally be the LMP91000. The LMP91000 is a front-end chip in an electrochemical workstation, integrating the voltage generation of a constant voltage operational amplifier and the transconductance of the current on the working electrode, allowing discrete components to be compactly integrated into a small area. The microprocessor sends commands to the LMP91000 via the I2C bus, and the LMP91000 generates the corresponding voltage and applies it to the electrochemical electrode to perform the measurement output. Within the LMP91000 chip, there is an input pin called Vref, which provides a reference voltage to the LMP91000. The output of the LMP91000 relies on this reference voltage (Vref) to generate output voltages of 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, and 22% of Vref, controlled by the output register VLMP within the LMP91000. Following the typical usage of the LMP91000, assuming a fixed 2.5V reference voltage is applied to Vref using a reference voltage chip, and the LMP91000's internal register VLMP is set to 10%, then the LMP91000's output will be 2.5V x 10% = 0.25V. This application uses a DAC to adjust the voltage Vref, changing the Vref input pin from a fixed value to a variable value, thus improving the LMP91000's output resolution.

[0031] Since the minimum input value of the LMP91000's Vref pin is specified as 1.5V in the datasheet, this design uses a non-inverting adder to combine the output of a reference voltage chip and the output of a DAC. When the DAC output is 0, the minimum output of the adder is 1.5V, which allows the LMP91000 to operate normally.

[0032] For example, if a 0.6V output is required, the CPU can use an exhaustive search method to find the values ​​of Vref and VLMP, multiply them to a value close to 0.6, within the error range. Firstly, assuming a 10-bit 5V DAC is used, the output resolution is 5 / 1024 = 0.0048mV. After passing through a non-inverting adder, it becomes 0.0048 * 3 / 5 = 0.003V. Finally, after the adder, it becomes 0.003 + 1.5 = 1.503V, which is the resolution provided to the Vref pin of the LMP91000.

[0033] Using an exhaustive search method, to obtain an output of 0.6V, and setting an error range of 0.003, the search starts from the lowest values ​​of Vref and VLMP, gradually increasing the value of VLMP from 0%, 2%, and so on. Then, it gradually increases the value of Vref from 1.503%, 1.506%, and so on, multiplying the values ​​to see if they fall within the error range of the desired 0.6V. Following this algorithm, when Vref = 2.726 and VLMP = 22%, a value of 0.599 is obtained, differing from 0.6V by 0.001, which is within the error range. The next step is for the CPU to input Vref 2.726 into the DAC, and VLMP and 22% into the LMP91000 register, which will then yield the required voltage.

[0034] The combination of an electrochemical sensor interface IC, a microprocessor, a DAC, and a proportional adder enables precise control of the electrode voltage. In particular, the connection between the microprocessor, DAC, and electrochemical sensor interface IC enables automated voltage control. At the same time, the DAC provides accurate digital-to-analog voltage conversion, accurately outputting the voltage value calculated by the microprocessor to the electrochemical sensor interface IC. The gain adjustment function of the proportional adder can finely adjust the output voltage while ensuring that the electrochemical workstation can operate for a long time without consuming excessive power.

[0035] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes a connection between the microprocessor and the electrochemical sensor interface IC via an I2C bus.

[0036] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes a connection between the microprocessor and the DAC via SPI.

[0037] The power control circuit proposed in this application combines the advantages of I2C and SPI protocols, enabling the power control circuit of the electrochemical workstation to have efficient communication capabilities, flexible hardware design, low power consumption, high-precision signal control, and expandability.

[0038] Preferred, such as Figure 3 The diagram shows the algorithm flowchart of the electrode voltage modulation circuit of the electrochemical workstation based on the LMP91000 chip described in this application. The specific process is as follows:

[0039] Step 1: Upon each power-up, initialize the microprocessor's reference voltage to the minimum Vref. Simultaneously, upon each power-up, initialize the electrochemical sensor interface IC's reference voltage to 0% of the minimum Vref.

[0040] Initializing the reference voltage of the microprocessor and electrochemical sensor interface IC to the lowest Vref and 0% of the lowest Vref ensures system stability and safety upon power-up, avoids voltage surges, protects sensor hardware, and reduces the impact of voltage fluctuations on the system. This also improves the reliability, data accuracy, hardware lifespan, and system fault tolerance of the electrochemical workstation, providing higher stability and better protection mechanisms, especially in precision experiments and long-term use.

[0041] Step 2: Gradually increase the VLMP value to 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, and 22%.

[0042] Step 3: Calculate the output voltage value each time the VLMP value increases.

[0043] Step 4: Compare the output voltage value with the required voltage to see if the error value is within the set range. If it is outside the error range, continue to increase the VLMP value until it reaches 22%.

[0044] If the difference between the output voltage and the required voltage is within the set error, then stop the calculation. Otherwise, if the difference is outside the set error, continue increasing the VLMP value up to 22%. If the requirement is still not met, increase the reference voltage by one level, then reset the VLMP value to 0%, and return to step 2 to successively increase the VLMP value and compare whether the voltage difference is within the set error, until the corresponding voltage is successfully matched.

[0045] Step 5: The microprocessor outputs instructions to the LMP91000 and DAC via I2C and SPI protocols, successfully outputting the corresponding voltage.

[0046] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes the microprocessor simultaneously sending voltage signals to the electrochemical sensor interface IC and DAC.

[0047] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes the DAC signal range from 0 to the maximum value of the electrochemical electrode voltage.

[0048] The power control circuit proposed in this application synchronously controls the electrochemical sensor interface IC and DAC via a microprocessor, providing a high-precision and stable voltage signal. This optimizes the voltage control process in electrochemical experiments, simplifies hardware design, and improves the system's response speed, stability, and flexibility. The DAC's signal range extends from 0 to the maximum value of the electrochemical electrode voltage, ensuring precise voltage control during the electrochemical reaction process and making experiments on the electrochemical workstation more reliable and precise.

[0049] Preferably, the electrochemical workstation electrode voltage modulation circuit based on the LMP91000 chip described in this application includes an electrochemical sensor interface IC that supports 12 levels of electrochemical electrode voltage, namely 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, and 22% of the reference voltage.

[0050] To further illustrate that the power control circuit described in this case can achieve arbitrary extension of the electrodes, such as... Figure 4 As shown, 3 is CE, the counter electrode; 2 is WE, the working electrode; and 1 is ref, the reference electrode.

[0051] In traditional electrochemical workstation configurations, the drive voltage is between ref and we, with an unknown voltage between ce and ref, influenced by the liquid level resistance in the electrolytic cell and the electrochemical reaction. Due to this unknown voltage Eu, the drive voltage E fails to reach the op-amp's power supply potential before the op-amp's output saturates. This invention enables a drive voltage configuration between ce and ref, eliminating any unknown voltage and allowing full-scale op-amp output.

[0052] In traditional electrochemical workstations, CE and RE are connected to the same op-amp and need to appear in pairs. RE and WE are coupled through the input voltage. If a new CE is to be added, a new Ref is added. The new configuration implementation makes CE, RE, and WE independent of each other, allowing multiple CEs or multiple WEs to be added, such as two machines used in parallel.

[0053] In traditional electrochemical workstations, a potential difference exists between CE, Ref, and WE. Therefore, when an equipotential surface is required in the electrolytic cell, traditional electrochemical workstations are not convenient for implementation. In this embodiment, since Ref is grounded and WE is at zero potential due to the virtual short principle of the operational amplifier, the potentials of WE and re are equal, both being 0. With proper electrode design in the electrolytic cell, an equipotential surface can be formed within the electrolytic cell. The electrode design and shape in the electrolytic cell are also crucial here.

[0054] The electrode voltage modulation circuit for an electrochemical workstation based on the LMP91000 chip described in this application is applicable to any electrochemical workstation.

[0055] For example, such as Figure 5 As shown, an exemplary electrode kit utilizes the LMP91000 chip-based electrochemical workstation electrode voltage modulation circuit described above. Its specific operation is as follows:

[0056] S1: During urination, place the leakage hole on the electrode kit into the urine stream, or immerse the leakage hole in the urine collection fluid until the internal fiberglass cotton is fully absorbed by the urine before removing the kit. During this process, avoid contact between the gold fingers of the distal contact plate and the liquid.

[0057] S2: Place the electrode kit upright and wait for excess urine to drip out along the direction of the cutter until the dripping stops.

[0058] S3: Remove the buffer bottle, align the cutter from the electrode kit with the rubber stopper on the buffer bottle, and forcefully insert it. The electrode kit will pierce the rubber stopper and insert into the interior of the buffer bottle.

[0059] S4: Gently shake the buffer bottle upright, being careful not to spill any liquid, to ensure that the liquid inside the electrode kit is fully mixed with the liquid inside the buffer bottle.

[0060] S5: Connect the electrochemical workstation to the gold fingers of the contact plate at the end of the electrode kit, and start the experiment by applying voltage according to the preset program of the electrochemical workstation.

[0061] The power control circuit of the electrochemical workstation proposed in this application has technical advantages such as high-precision voltage control, rich voltage adjustment options, flexible data transmission methods, and strong system stability. By combining multiple modules such as microprocessor, DAC, and proportional adder into a unified control system, the system design and integration process is simplified, the number of hardware modules is reduced, the system cost is lowered, and the overall system stability and reliability are improved, effectively enhancing the performance and reliability of the electrochemical workstation.

[0062] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0063] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0064] Although the description of this application has been given in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. An electrode voltage modulation circuit for an electrochemical workstation based on the LMP91000 chip, characterized in that: This includes an electrochemical sensor interface IC, a microprocessor, a DAC, and a proportional adder; The electrochemical sensor interface IC is connected to a chemical electrode at one end and to a microprocessor at the other end. The other end of the microprocessor is connected to the DAC; The DAC is connected to the positive input of the proportional adder; the negative output of the proportional adder is connected to the VREF port of the electrochemical sensor interface IC.

2. The electrode voltage modulation circuit for an electrochemical workstation based on the LMP91000 chip according to claim 1, characterized in that, Each time the microprocessor is powered on, its reference voltage is initialized to the minimum Vref.

3. The electrode voltage modulation circuit for an electrochemical workstation based on the LMP91000 chip according to claim 2, characterized in that, Each time power is applied, the reference voltage of the electrochemical sensor interface IC is initialized to 0% of the lowest Vref.

4. The electrode voltage modulation circuit of an electrochemical workstation based on the LMP91000 chip according to claim 3, characterized in that, The microprocessor and the electrochemical sensor interface IC are connected via an I2C bus.

5. The electrode voltage modulation circuit of an electrochemical workstation based on the LMP91000 chip according to claim 4, characterized in that, The microprocessor and the DAC are connected via SPI.

6. The electrode voltage modulation circuit of an electrochemical workstation based on the LMP91000 chip according to claim 5, characterized in that, The microprocessor simultaneously sends voltage signals to the electrochemical sensor interface IC and DAC.

7. The electrode voltage modulation circuit of an electrochemical workstation based on the LMP91000 chip according to claim 6, characterized in that, The signal range of the DAC is from 0 to the maximum value of the electrochemical electrode voltage.

8. The electrode voltage modulation circuit of an electrochemical workstation based on the LMP91000 chip according to claim 7, characterized in that, The electrochemical sensor interface IC supports 12 levels of electrochemical electrode voltage, namely 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, and 22% of the reference voltage.

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