Power drive circuit and blood gas analyzer

Abstract

The utility model discloses a power supply driving circuit and a blood gas analyzer. The power supply driving circuit comprises a first power supply chip, a second power supply chip and a differential amplifier, and the temperature excursion and the driving capability of the first power supply chip are higher than those of the second power supply chip. And the differential amplifier is used for amplifying a differential value between the driving voltage output by the first power supply chip and the second power supply reference voltage, and outputting a regulating voltage to regulate the driving voltage. By means of the circuit, the driving voltage for low-temperature drift and high-current driving of the blood gas analyzer can be generated, the stability and reliability of operation of the blood gas analyzer can be improved, and therefore the blood gas analyzer can obtain more accurate and robust blood gas detection and analysis results.

Description

Technical Field

[0001] The present application relates to the technical field of medical equipment, and in particular to a power drive circuit and a blood gas analyzer. Background Art

[0002] Among medical devices, a blood gas analyzer is a medical device used to measure the concentration of gases such as oxygen and carbon dioxide in the blood. The blood gas analyzer needs to be driven stably and reliably by a power drive circuit to ensure the normal operation of the device and the accuracy of the measurement results. Therefore, it has extremely high requirements for the current driving capability and stability of its power drive circuit.

[0003] However, the power chip used in the power drive circuit of the traditional blood gas analyzer cannot take into account both its current driving capability and the stability of the output voltage. The power chip with low temperature drift has the problem of insufficient current driving capability, while the power chip with strong current driving capability has a higher temperature drift. Therefore, it is difficult for the existing power drive chip to take into account both high current driving capability and low temperature drift. This is not conducive to the reliable and stable operation of the blood gas analyzer, nor is it conducive to the accuracy and robustness of its blood gas detection and analysis results. Utility Model Content

[0004] The present application mainly provides a power drive circuit and a blood gas analyzer, aiming to solve the technical problem that the existing power drive circuit is difficult to take into account both low temperature drift and high current driving capability.

[0005] In order to solve the above technical problems, the technical solution adopted in the present application is: to provide a power drive circuit. The power drive circuit includes: a first power chip, which is used to adjust the first power voltage received by the first power access terminal based on the internal reference voltage and the adjustment voltage connected to the voltage adjustment terminal to obtain a driving voltage, and output the driving voltage through the first output terminal; a second power chip, which is used to generate a reference voltage and output the reference voltage through the second output terminal; a differential amplifier, including a first input terminal, a second input terminal and a third output terminal, wherein the first input terminal is connected to the first output terminal, the second input terminal is connected to the second output terminal, and the third output terminal is connected to the voltage adjustment terminal, and is used to amplify the difference between the driving voltage and the reference voltage to output the adjustment voltage; wherein the temperature drift and driving capability of the first power chip are higher than the temperature drift and driving capability of the second power chip, the driving current of the first power chip is not less than 150mA, and the temperature drift of the second power chip is not more than 5ppm.

[0006] In some embodiments, the first power chip includes: a reference voltage source, used to generate the internal reference voltage, and output the internal reference voltage through the fourth output terminal; an internal amplifier, including the voltage regulation terminal, the third input terminal and the fifth output terminal, the third input terminal is connected to the fourth output terminal, used to generate a control voltage based on the regulation voltage and the internal reference voltage, and output the control voltage through the fifth output terminal; an adjustment element, including the first power access terminal, the fourth input terminal and the first output terminal, the fourth input terminal is connected to the fifth output terminal, used to control the first power voltage based on the control voltage to obtain the driving voltage.

[0007] In some embodiments, the adjustment element includes any one of a triode, a MOS tube and an IGBT tube.

[0008] In some embodiments, the reference voltage source includes an enable terminal, and the reference voltage source generates the internal reference voltage in response to an enable signal received at the enable terminal.

[0009] In some embodiments, the second power chip includes a second power access terminal and a second output terminal, the second power access terminal is connected to a second power voltage, and the second power chip is used to perform a reference correction on the second power voltage to output the reference voltage.

[0010] In some embodiments, the first power supply voltage is 5V to 5.4V, and the second power supply voltage is 5.275V to 5.4V.

[0011] In some embodiments, the power driving circuit also includes a filtering branch, which includes a current limiting resistor connected in series between the differential amplifier and the first power chip, and a filtering capacitor having one end connected between the current limiting resistor and the first power chip and the other end connected to ground.

[0012] In some embodiments, the first power chip is an adjustable voltage LDO chip, and the second power chip is a reference voltage chip.

[0013] In some embodiments, the model of the first power chip is MIC5205, and the model of the second power chip is MAX6126.

[0014] In order to solve the above technical problems, another technical solution adopted in the present application is: to provide a blood gas analyzer, which includes the power drive circuit as mentioned above.

[0015] The beneficial effect of the present application is that, different from the prior art, the present application discloses a power drive circuit and a blood gas analyzer. The present application generates a driving voltage through a first power chip with a relatively high current driving capability, and processes a reference voltage generated by a second power chip with a relatively low temperature drift with the driving voltage through a differential amplifier to generate an adjustment voltage to adjust the driving voltage, thereby obtaining the power drive chip with both high current driving capability and low temperature drift, which is beneficial to improving the stability and reliability of the operation of the blood gas analyzer, thereby enabling the blood gas analyzer to obtain more accurate and robust blood gas detection and analysis results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0017] Figure 1 is a structural schematic diagram of an embodiment of a power drive circuit provided by the present application;

[0018] Figure 2 yes Figure 1 A schematic structural diagram of an embodiment of a first power chip U1 in the embodiment;

[0019] Figure 3 is a structural schematic diagram of another embodiment of the power drive circuit provided by the present application;

[0020] Figure 4 It is a structural schematic diagram of an embodiment of a blood gas analyzer provided in the present application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] The terms "first", "second", "third", etc. in the embodiments of the present application are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third", etc. can expressly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically limited. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0023] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] The present application provides a power drive circuit, referring to Figure 1 , Figure 1 It is a flow chart of an embodiment of a power driving circuit 100 provided in the present application.

[0025] The power driving circuit 100 includes: a first power chip U1, which is used to adjust the first power voltage received by the first power access terminal VIN1 based on the internal reference voltage and the adjustment voltage connected to the voltage adjustment terminal ADJ to obtain a driving voltage, and output the driving voltage through the first output terminal OUT1; a second power chip U2, which is used to generate a reference voltage, and output the reference voltage through the second output terminal OUT2; a differential amplifier U3, which includes a first input terminal IN1, a second input terminal IN2 and a third output terminal OUT3, the first input terminal IN1 is connected to the first output terminal OUT1, the second input terminal IN2 is connected to the second output terminal OUT2, and the third output terminal OUT3 is connected to the voltage adjustment terminal ADJ, and is used to amplify the difference between the driving voltage and the reference voltage to output the adjustment voltage; wherein the temperature drift and driving capability of the first power chip U1 are higher than the temperature drift and driving capability of the second power chip U2.

[0026] Temperature drift and current driving capability are the embodiment of the performance of power chips. Temperature drift refers to the degree to which the output voltage of the power chip changes with temperature during operation. The smaller the temperature drift, the less the output voltage of the power chip is affected by temperature and the better the stability. The current driving capability refers to the maximum output current that the power chip can provide, which determines how large a load the power chip can drive. However, traditional power chips often find it difficult to achieve both high current driving capability and low temperature drift performance. Power chips with low temperature drift often have insufficient current driving capability and cannot work well under load. Power chips with strong current driving capability often have higher temperature drift, resulting in unstable driving current.

[0027] Inside the first power chip U1, since its internal reference voltage is the standard value used as a reference for other voltages in its chip circuit, the temperature drift of the internal reference voltage will be amplified and affect the output of the entire circuit. Therefore, the temperature drift inside the first power chip U1 mainly comes from the internal reference voltage. Therefore, if the influence of the temperature drift of the internal reference voltage on the driving voltage output by the first power chip U1 can be effectively suppressed, a driving voltage with smaller temperature drift can be obtained.

[0028] The present application can effectively suppress the influence of the temperature drift of the internal reference voltage on the driving voltage: assuming that the driving voltage is U_out, the reference voltage is U_ref, the adjustment voltage is U_adj, the multiple of the differential amplifier U3 is A, and the internal reference voltage is U_bgr, and when the temperature drift is small, no adjustment is required, that is, U_bgr=U_adj, then according to the above circuit structure, the corresponding formula can be obtained, that is, U_bgr=U_adj=A(U_out-U-ref), so that U_out=U_bgr / A+U_ref can be determined, so when the temperature drift caused by the internal reference voltage occurs, if the offset of the internal reference voltage is ΔU, then the temperature drift of the driving voltage will actually be reduced by A times. At the same time, since the internal reference voltage U_bgr of the first power chip U1 is much smaller than the reference voltage U_ref, the influence of the internal reference voltage U_bgr will be further reduced when it is reflected on U_out, so that the temperature drift of the driving voltage U_out output by the circuit is approximately equal to the temperature drift of the second power chip U2, that is, it reflects a relatively low temperature drift. Therefore, the obtained circuit structure can effectively take into account the performance of high current driving capability and low temperature drift, and can output a driving voltage with high current driving capability and low temperature drift from the first output terminal, which is conducive to meeting the requirements of the blood gas analyzer for the stability and reliability of the power supply voltage.

[0029] Among them, the differential amplifier U3 is an amplifier with two input terminals and one output terminal, and usually different resistors are also required at its input terminal, output terminal and feedback terminal to control the adjustment magnification. The differential amplifier U3 can effectively amplify the voltage difference between the two input terminals and output the amplified voltage difference to the output terminal. In the present application, the differential amplifier U3 is used to amplify the differential value between the driving voltage and the reference voltage to output the adjustment voltage. Since the differential amplifier U3 has the characteristics of high precision, high stability and high magnification, it can effectively amplify the differential value between the driving voltage and the reference voltage, and output it to the voltage adjustment terminal ADJ, thereby realizing the precise adjustment of the output driving voltage of the first power chip U1.

[0030] Through this circuit structure, the present application forms a closed-loop negative feedback regulation circuit by connecting the differential amplifier U3 between the first power chip U1 and the second power chip U2. The circuit can monitor the difference between the driving voltage output by the first power chip U1 and the reference voltage output by the second power chip U2 in real time, and amplify the difference through the differential amplifier U3, thereby adjusting the reference voltage inside the first power chip U1 to achieve precise control of the driving voltage. This circuit structure can effectively suppress the influence of the temperature drift of the internal reference voltage of the first power chip U1 on the driving voltage, so that the driving voltage output by the first power chip U1 can take into account both high driving current and low temperature drift. This circuit structure not only improves the stability and reliability of the power drive circuit 100, but also has the characteristics of low cost and low complexity, is easy to design and deploy, and can be well applied to electronic devices such as blood gas analyzers that require stable and reliable power supply voltages, which is conducive to improving the performance of these equipment and instruments.

[0031] Optionally, the driving current of the first power chip U1 is not less than 150 mA.

[0032] Medical equipment such as blood gas analyzers are usually used to drive larger loads during operation, which requires the power drive circuit 100 to provide sufficient current. If the driving current of the power chip is insufficient, it may not be able to drive these loads, causing the device to fail to work properly. Therefore, the first power chip U1 needs to be able to provide at least 150mA of driving current to meet the needs of the device. Such a setting not only ensures the stability of the power drive circuit 100, but also effectively ensures the stability of the power drive circuit 100 and the normal operation of the device.

[0033] Optionally, the temperature drift of the second power chip U2 is no more than 5 ppm.

[0034] As the output source of the reference voltage, the temperature drift of the second power chip U2 has an important influence on the stability and reliability of the entire power drive circuit 100. The larger the temperature drift, the greater the influence of temperature on the output voltage of the second power chip U2, which will further affect the accuracy of the differential amplifier U3 in amplifying the differential value between the drive voltage and the reference voltage, resulting in instability of the final output drive voltage. Therefore, in order to ensure the stability and reliability of the power drive circuit 100, the temperature drift of the second power chip U2 needs to be controlled within a certain range. Specifically, the temperature drift of the second power chip U2 is not greater than 5ppm, which is a suitable choice. Such a setting can effectively reduce the influence of temperature on the reference voltage, thereby improving the accuracy of the differential amplifier U3 in amplifying the differential value, and finally obtaining a more stable and reliable drive voltage.

[0035] Under the requirements of the driving current and temperature drift, a good selection can usually be made for the first power chip U1 and the second power chip U2. Through the aforementioned circuit architecture, a power driving circuit 100 that takes into account both low temperature drift and high current drive can be obtained. In addition, it should be understood that the limitation of the current driving capability of "not less than 150mA" is an exemplary minimum requirement, and "not more than 5ppm" is an exemplary maximum limit. In fact, according to the performance of the power chip and the specific application scenario, the requirements for the current drive and temperature drift can be adaptively adjusted and determined according to specific needs and conditions to ensure the stability and reliability of the driving voltage. In addition, there will be certain requirements for the driving voltage and reference voltage of the first power chip U1 and the second power chip U2 in different equipment and instruments. For example, the requirement for the driving voltage in the existing blood gas analyzer is usually 5V, but it may be different in other medical equipment. It is specifically necessary to formulate corresponding standards for the driving voltage according to the regulations of different chip manufacturers, the performance indicators of different manufacturing processes, and the performance requirements of different application scenarios, and select appropriate components to make corresponding adjustments and optimizations to meet specific needs.

[0036] Optionally, the first power chip U1 is an adjustable voltage LDO chip, and the second power chip U2 is a reference voltage chip.

[0037] As the output source of the driving voltage, the first power chip U1 needs to have the ability to adjust the voltage to meet the different driving voltage requirements of different equipment and instruments. The adjustable voltage LDO (Low Dropout Regulator) chip is a common type of power chip, which can adjust the output voltage within a certain range, and has a lower voltage difference and a higher power supply rejection ratio, and can provide a stable and reliable driving voltage. Therefore, it is a suitable choice to select the first power chip U1 as an adjustable voltage LDO chip.

[0038] As the output source of the reference voltage, the second power chip U2 needs to have the characteristics of high precision and low temperature drift to ensure the accuracy of the differential amplifier U3 in amplifying the differential value between the driving voltage and the reference voltage. The reference voltage chip is a power chip specially used to output a high-precision, low-temperature drift reference voltage, which can meet this requirement. Therefore, it is a suitable choice to select the second power chip U2 as the reference voltage chip, which can ensure that a low-temperature drift reference voltage is obtained.

[0039] Through the above steps, the first power chip U1 is selected as an LDO chip with adjustable voltage, and the second power chip U2 is selected as a reference voltage chip, so that a power drive circuit 100 that can take into account both high current driving capability and low temperature drift can be obtained, which can effectively meet the power drive circuit 100's requirements for driving voltage and reference voltage, thereby improving the stability and reliability of the entire power drive circuit 100, so as to meet the requirements of medical equipment such as blood gas analyzers for the stability and reliability of power supply voltage, and improve the performance of equipment and instruments. At the same time, the circuit structure also has the characteristics of low cost and low complexity, is easy to design and deploy, and has high practicality and promotion value.

[0040] Optionally, the model of the first power chip U1 is MIC5205, and the model of the second power chip U2 is MAX6126.

[0041] MIC5205 and MAX6126 are two power supply chips with excellent performance. They have the characteristics of adjustable voltage, high current drive and low temperature drift respectively, and are suitable for the power supply drive circuit 100 in this application. Among them, MIC5205 is one of the LDO chips, which can output an adjustable drive current of not less than 150mA, and has excellent power supply rejection ratio and linear regulation rate, which can ensure the stability and reliability of the drive voltage. MAX6126 is a high-precision, low-temperature drift reference voltage chip, which can provide a very stable and accurate reference voltage. Its output voltage is 5V and the temperature drift is 3ppm, which helps to improve the accuracy of differential amplifier U3 to differential value amplification, thereby obtaining a more stable and reliable drive voltage. Therefore, selecting MIC5205 as the first power supply chip U1 and / or selecting MAX6126 as the second power supply chip U2 can well meet the needs of the power supply drive circuit 100 in this application, improve the stability and reliability of the entire circuit, and ensure the normal operation of the equipment and instruments.

[0042] It should be noted that in actual applications. For example, in different equipment and instruments, the requirements for driving voltage and reference voltage may be different, and the first power chip U1 and the second power chip U2 need to be selected and adjusted according to the actual situation. In addition, factors such as the cost and availability of the power chip need to be considered to ensure the overall performance and cost-effectiveness of the power drive circuit 100. The two chips provided above can be selected at the same time, or only one of them can be selected, or neither of them can be selected, and other chips that meet the relevant restrictions in current driving capability and temperature drift performance can be selected.

[0043] For example, the model of the first power chip U1 is MIC5205, and the model of the second power chip U2 is MAX6126. The internal temperature drift of the first power chip U1MIC5205 is 40ppm / ℃, and the internal reference voltage of the chip is U_bgr=150mv without considering the temperature drift; the differential amplifier circuit is designed with a magnification of A=499; the temperature drift of the second power chip U2MAX6126 providing the reference voltage U_ref is 3ppm / ℃, and according to the voltage calculation formula derived above: U_out=U_bgr / A+U_ref, the final output voltage U_out of the circuit is approximately equal to the reference voltage U_ref, and therefore the temperature drift of the final output voltage of the circuit is approximately equal to the temperature drift of the reference voltage provided by the second power chip U2MAX6126. The actual temperature drift should be 40 / 499+3≈3.08016ppm / ℃, which is the output voltage temperature drift of the entire circuit when the first power chip U1MIC5205 produces the maximum forward temperature drift and the second power chip U2MAX6126 produces the maximum reverse temperature drift, or when U1 produces the maximum reverse temperature drift and U2 produces the maximum forward temperature drift.

[0044] Optionally, see Figure 2 The first power chip U1 includes: a reference voltage source U1_1, which is used to generate an internal reference voltage and output the internal reference voltage through a fourth output terminal OUT4; an internal amplifier U1_2, which includes a voltage adjustment terminal ADJ, a third input terminal IN3 and a fifth output terminal OUT5, the third input terminal IN3 is connected to the fourth output terminal OUT4, and is used to generate a control voltage based on the adjustment voltage and the internal reference voltage, and output the control voltage through the fifth output terminal OUT5; an adjustment element U1_3, which includes a first power access terminal VIN1, a fourth input terminal IN4 and a first output terminal OUT1, the fourth input terminal IN4 is connected to the fifth output terminal OUT5, and is used to control the first power voltage based on the control voltage to obtain a driving voltage.

[0045] The reference voltage source U1_1 is an important component of the power drive circuit 100. It can provide a stable and accurate reference voltage to provide a reference for subsequent voltage regulation and amplification. In the first power chip U1, the reference voltage source U1_1 is responsible for generating an internal reference voltage U_bgr and outputting it through the fourth output terminal OUT4. This internal reference voltage is the basis for the operation of the internal circuit of the chip, and is crucial to ensuring the stability and reliability of the entire power drive circuit 100. The reference voltage source U1_1 in the first power chip U1 can be a bandgap reference circuit (Bandgap Voltage Reference, BGR), or a voltage reference circuit based on a voltage regulator such as a Zener diode (Zener Diode) or a Schottky diode (Schottky Diode), or a circuit structure that can effectively provide a reference voltage and the like designed according to the characteristics of the circuit structure. Regardless of which type of reference voltage source U1_1 is used, it is at least necessary to ensure that the internal reference voltage provided by the reference voltage source U1_1 has high accuracy and stability, and can effectively provide sufficient drive current after corresponding processing based on the reference voltage in the first power chip U1.

[0046] The internal amplifier U1_2 is responsible for generating a control voltage according to the adjustment voltage and the internal reference voltage to achieve adjustment control of the adjustment element U1_3, and then control the driving voltage. In the first power chip U1, the internal amplifier U1_2 receives the externally provided adjustment voltage through the voltage adjustment terminal ADJ, and receives the internal reference voltage from the third input terminal IN3. Since the internal amplifier U1_2 is a type of amplifier, it meets the characteristics of virtual short and virtual break, so that the current at the input end of the internal amplifier U1_2 is close to 0, and the voltage of the voltage adjustment terminal ADJ is equal to the internal reference voltage, thereby satisfying the equation relationship in the above example that the adjustment voltage U_adj is approximately equal to the internal reference voltage U_bgr. The internal amplifier U1_2 then compares and amplifies the two voltages, generates a control voltage, and outputs it through the fifth output terminal OUT5. This control voltage will directly act on the adjustment element U1_3, thereby achieving precise control of the driving voltage. In practical applications, the internal amplifier U1_2 can be implemented using circuit structures such as an operational amplifier and a differential amplifier U3. The specific selection depends on factors such as circuit design requirements, performance requirements, and cost considerations.

[0047] The adjustment element U1_3 is the execution part in the power chip, which controls the first power supply voltage according to the control voltage to obtain the driving voltage. There are many specific implementation methods of the adjustment element U1_3. For example, it can be an adjustable resistor to adjust the driving voltage by changing the resistance value, or it can be a switching element such as a power transistor or a MOS tube (Metal Oxide Semiconductor Field Effect Transistor) to adjust the driving voltage by changing its conduction degree, or it can also be a controller based on control algorithms such as PWM (Pulse Width Modulation), PID (Proportional Integral Derivative Control) or fuzzy control. The driving voltage output by the adjustment element U1_3 for adjusting the first power supply voltage will be directly provided to the equipment and instrument for use, so its stability and reliability are crucial to the normal operation of the equipment and instrument. In practical applications, the selection of the adjustment element U1_3 should be determined based on factors such as the specific needs of the circuit, performance requirements, and cost considerations.

[0048] In addition, in addition to the reference voltage source U1_1, the internal amplifier U1_2 and the adjustment element U1_3, the first power chip U1 may also include other auxiliary circuits and elements, such as filter circuits, protection circuits, etc., to improve the performance and reliability of the power drive circuit 100. The circuit structure of the first power chip U1 achieves precise control of the drive voltage and improves the stability and reliability of the power drive circuit 100 by adopting a circuit design or algorithm such as a high-precision reference voltage source U1_1, flexible voltage regulation, an efficient and stable adjustment element U1_3, and enhancement of auxiliary circuits and elements. It can be well applied to electronic devices such as blood gas analyzers that require stable and reliable power supply voltages, which is conducive to improving the performance of these devices and instruments.

[0049] Optionally, the adjustment element U1_3 includes any one of a triode, a MOS tube and an IGBT tube.

[0050] The triode (Bipolar Junction Transistor, BJT) is a commonly used semiconductor device with current amplification function, and can be used in the adjustment element U1_3. When the triode is used as the adjustment element U1_3, its base receives the control voltage, and the collector current is controlled by changing the base current, thereby adjusting the driving voltage. The triode has the advantages of fast response speed and high adjustment accuracy, so it is often used as the adjustment element U1_3 in some power supply circuits that require fast response and precise adjustment.

[0051] MOS tube is a high-performance semiconductor device with advantages such as high input impedance, low noise, and low power consumption. In the power chip, MOS tube can be used as an adjustment element U1_3 to control the drain current by changing the gate voltage, thereby adjusting the drive voltage. MOS tube has the characteristics of wide dynamic range, high efficiency, and high reliability, so it is widely used in many power circuits.

[0052] IGBT (Insulated Gate Bipolar Transistor) is a semiconductor device that combines the characteristics of MOSFET and GTO (Giant Transistor), and has the advantages of high speed, high efficiency, and high reliability. IGBT can be used as an adjustment element U1_3 in the power supply circuit to control the collector current by changing the gate voltage, thereby adjusting the drive voltage. IGBT has the characteristics of high current handling capability, low conduction loss, and good thermal stability, so it is widely used in some power supply circuits that need to handle large currents and high temperature environments.

[0053] The triode, MOS tube or IGBT tube can be used as the adjustment element U1_3 in the power chip. The specific selection should be determined according to the specific needs of the circuit, performance requirements and cost considerations. In practical applications, it is also necessary to reasonably design and adjust the parameters and circuit structure of the element U1_3 according to the characteristics and requirements of the specific circuit to ensure the stability and reliability of the power circuit.

[0054] Optionally, the reference voltage source U1_1 includes an enable terminal EN, and the reference voltage source U1_1 generates an internal reference voltage in response to an enable signal received by the enable terminal EN.

[0055] The enable terminal EN is a control signal input terminal used to control the working state of the reference voltage source U1_1. When the enable terminal EN receives the enable signal, the reference voltage source U1_1 is activated and starts to generate an internal reference voltage. The enable signal is usually a high level or low level signal, depending on the requirements of the circuit design. By introducing the enable terminal EN, the control of the reference voltage source U1_1 can be achieved, thereby achieving control of the entire power supply circuit. In practical applications, the enable terminal EN can be connected to other circuits or system control signals to achieve a more flexible control method. For example, the level state of the enable terminal EN can be controlled by an external control signal, thereby controlling the opening and closing of the reference voltage source U1_1 to adapt to different working scenarios and requirements.

[0056] The introduction of the enable terminal EN can improve the reliability and safety of the power circuit. In some cases, when the power circuit fails or is abnormal, the reference voltage source U1_1 can be turned off by controlling the signal of the enable terminal EN, thereby avoiding the expansion of the fault or damage to other circuit components. A more flexible, reliable and safe control method is provided for the circuit of the first power chip U1. By reasonably designing and using the enable terminal EN, effective control of the power circuit can be achieved, the stability and reliability of the circuit can be improved, and a strong guarantee can be provided for the normal operation of electronic equipment.

[0057] Optionally, the second power chip U2 includes a second power access terminal VIN2 and a second output terminal OUT2, the second power access terminal VIN2 is connected to the second power voltage, and the second power chip U2 is used to perform a reference correction on the second power voltage to output a reference voltage.

[0058] The second power chip U2 uses the second power voltage as the power source for the chip to work, and performs a reference correction on the second power voltage to generate a more accurate reference voltage. Among them, the reference correction is an electronic processing technology that accurately adjusts the power voltage through a specific circuit design or algorithm, such as using resistor voltage division, feedback adjustment, digital calibration, etc., to eliminate the influence of factors such as voltage fluctuations and temperature drift on the power quality, so as to adjust and stabilize the power voltage, thereby eliminating the fluctuations and errors of the power voltage and ensuring the stability and reliability of the circuit. After the reference correction, the second power chip U2 outputs a reference voltage through the second output terminal OUT2. The reference voltage has high precision and stability. At the same time, under the limitation of the above-mentioned low temperature drift, it is used as a reference standard for the adjustment voltage of the first power chip U1. Combined with the high current driving capability of the first power chip U1, it can be better applied to blood gas analyzers and other equipment with high requirements for stability and accuracy.

[0059] The second power chip U2 takes the MAX1626 reference voltage chip in the previous example as an example, and its pins include NR, IN, GND, GNDS, OUTF, etc., wherein a capacitor is connected between the NR pin and the analog ground to suppress power supply noise, and the IN pin is the second power access terminal VIN2, which is used to access the second power supply voltage, GND and SGND are directly grounded or indirectly grounded through a resistor, etc., and OUTF is used as an output terminal to output a reference voltage. Thus, the MAX1626 chip can output a corresponding reference voltage according to its input-output relationship for subsequent regulation of voltage generation.

[0060] Optionally, the first power supply voltage connected to the first power supply terminal VIN1 is 5V to 5.4V, and the second power supply voltage connected to the second power supply terminal VIN2 is 5.275V to 5.4V.

[0061] The power supply voltage is specified to be able to generate a 5V reference voltage and a final driving voltage. In the first power supply chip U1 and the second power supply chip U2, in order to ensure the stability and reliability of the power supply chip, the operating voltage range of the power supply chip is usually specified. If the power supply voltage is too high or too low, it may cause the power supply chip to fail to work properly or even be damaged. In this example, the first power supply chip U1 has a strong current driving capability and therefore has less internal voltage loss. Its first power supply voltage can be relatively lower, but it must still be above 5V. In order to provide a low temperature drift reference voltage, the second power supply voltage usually consumes a certain amount of voltage during the process of temperature drift suppression and processing, so the required power supply voltage requirement is higher.

[0062] The specific actual first power supply voltage and the second power supply voltage can be determined according to the performance parameters of the chip used. The range of the power supply voltage defined above can better enable the MIC5205 chip and the MAX6126 chip in the previous example to respectively provide the corresponding low-temperature drift reference voltage and high-current drive voltage, and combined with the circuit structure of the present application, the power supply drive circuit 100 that takes into account both low-temperature drift and high-current drive capabilities can be comprehensively obtained, which is beneficial to improving the stability and reliability of the operation of the blood gas analyzer, so that the blood gas analyzer can obtain more accurate and robust blood gas detection analysis results.

[0063] In addition, it is worth noting that the operating voltage ranges of the two power chips overlap to a certain extent, namely 5.275V to 5.4V. This means that in practical applications, we can choose to use one power supply voltage to supply both the first power chip U1 and the second power chip U2. As long as this power supply voltage is within the range of 5.275V to 5.4V, it can meet the working requirements of the two power chips, as long as the power supply voltage has sufficient load capacity. This approach can simplify circuit design, reduce costs, and improve system reliability and stability.

[0064] Optionally, see Figure 3 The power driving circuit 100 also includes a filter branch 110, which includes a current limiting resistor R1 connected in series between the differential amplifier U3 and the first power chip U1, and a filter capacitor C1 with one end connected between the current limiting resistor R1 and the first power chip U1 and the other end grounded.

[0065] In the power drive circuit 100, due to the influence of factors such as power supply voltage fluctuations and thermal noise of circuit components, some noise and interference may be generated in the power signal, and these noise and interference may have an adverse effect on the normal operation of the circuit. In this example, the filter branch 110 includes a current limiting resistor R1 and a filter capacitor C1. The current limiting resistor R1 is connected in series between the differential amplifier U3 and the first power chip U1, and its main function is to limit the current and protect the circuit components from being damaged by excessive current.

[0066] At the same time, the current limiting resistor R1 can also play a role in voltage division, reducing the voltage difference between the differential amplifier U3 and the first power chip U1, thereby reducing the noise and interference in the circuit. One end of the filter capacitor C1 is connected between the current limiting resistor R1 and the first power chip U1, and the other end is grounded. Its main function is to filter out high-frequency noise and interference in the power signal. The filter capacitor C1 can be regarded as an energy storage element. When high-frequency noise and interference appear in the power signal, the filter capacitor C1 can absorb these noise and interference, and convert them into electric charge and store them, thereby playing a filtering role. At the same time, the filter capacitor C1 can also provide the stable DC voltage required by the circuit to ensure the normal operation of the circuit.

[0067] In practical applications, the design of the filter branch 110 needs to be carried out according to the specific circuit requirements and noise conditions. The resistance value of the current limiting resistor R1 needs to be reasonably selected according to the current size in the circuit and the withstand voltage capacity of the component to ensure the safety and stability of the circuit. The capacity and type of the filter capacitor C1 also need to be selected according to the frequency and noise conditions of the power signal to achieve effective filtering of the power signal. At the same time, the grounding method of the filter capacitor C1 also needs to be considered to avoid introducing new noise and interference. Therefore, by introducing the filter branch 110, these noises and interferences can be effectively filtered out, the quality and stability of the power signal can be improved, and the normal operation of the circuit can be ensured.

[0068] See also Figure 4 , Figure 4 It is a structural schematic diagram of an embodiment of a blood gas analyzer provided in the present application.

[0069] The blood gas analyzer 200 includes Figures 1 to 3 The described power drive circuit 100. The blood gas analyzer 200 can be a blood sample collection blood gas analyzer, a chemical analysis blood gas analyzer, an optical analysis blood gas analyzer, a hemodialysis measurement analyzer, a breath analyzer, etc., and this application does not make specific restrictions on this.

[0070] Different from the prior art, the present application discloses a power drive circuit and a blood gas analyzer. A driving voltage is generated by a first power chip with a relatively high current driving capability, and a reference voltage generated by a second power chip with a relatively low temperature drift and the driving voltage are processed through a differential amplifier to generate an adjustment voltage to adjust the driving voltage, thereby obtaining a power drive chip that takes into account both high current driving capability and low temperature drift, which is beneficial to improving the stability and reliability of the operation of the blood gas analyzer, thereby enabling the blood gas analyzer to obtain more accurate and robust blood gas detection and analysis results.

[0071] In the several embodiments provided in the present application, it should be understood that the disclosed power drive circuit and blood gas analyzer can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0072] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0073] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0074] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A power drive circuit, characterized in that: include: A first power chip, used for adjusting the first power voltage received by the first power access terminal based on the internal reference voltage and the adjustment voltage connected to the voltage adjustment terminal to obtain a driving voltage, and outputting the driving voltage through the first output terminal; A second power chip, used for generating a reference voltage and outputting the reference voltage through a second output terminal; a differential amplifier, comprising a first input terminal, a second input terminal and a third output terminal, wherein the first input terminal is connected to the first output terminal, the second input terminal is connected to the second output terminal, and the third output terminal is connected to the voltage regulating terminal, and is used to amplify the difference between the driving voltage and the reference voltage to output the regulating voltage; The temperature drift and driving capability of the first power chip are higher than those of the second power chip, the driving current of the first power chip is not less than 150mA, and the temperature drift of the second power chip is not greater than 5ppm.

2. The power drive circuit according to claim 1, characterized in that: The first power chip comprises: A reference voltage source, used to generate the internal reference voltage and output the internal reference voltage through a fourth output terminal; an internal amplifier, comprising the voltage regulating terminal, a third input terminal and a fifth output terminal, wherein the third input terminal is connected to the fourth output terminal, and is used to generate a control voltage based on the regulating voltage and the internal reference voltage, and output the control voltage through the fifth output terminal; The adjustment element includes the first power supply input terminal, a fourth input terminal and the first output terminal, wherein the fourth input terminal is connected to the fifth output terminal and is used to control the first power supply voltage based on the control voltage to obtain the driving voltage.

3. The power driving circuit according to claim 2, characterized in that: The adjustment element includes any one of a triode, a MOS tube and an IGBT tube.

4. The power driving circuit according to claim 2, characterized in that: The reference voltage source includes an enable terminal, and the reference voltage source generates the internal reference voltage in response to an enable signal received by the enable terminal.

5. The power driving circuit according to claim 1, characterized in that: The second power chip includes a second power access terminal and a second output terminal. The second power access terminal is connected to a second power voltage. The second power chip is used to perform a reference correction on the second power voltage to output the reference voltage.

6. The power drive circuit according to claim 5, characterized in that: The first power supply voltage is 5V to 5.4V, and the second power supply voltage is 5.275V to 5.4V.

7. The power driving circuit according to claim 1, characterized in that: The power drive circuit also includes a filter branch, which includes a current limiting resistor connected in series between the differential amplifier and the first power chip, and a filter capacitor with one end connected between the current limiting resistor and the first power chip and the other end connected to ground.

8. The power driving circuit according to claim 1, characterized in that: The first power chip is an adjustable voltage LDO chip, and the second power chip is a reference voltage chip.

9. The power driving circuit according to claim 1, characterized in that: The model of the first power chip is MIC5205, and the model of the second power chip is MAX6126.

10. A blood gas analyzer, characterized in that: The invention comprises a power driving circuit as claimed in any one of claims 1 to 9.

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