A high-precision current output method and a high-precision constant current source system

Abstract

This invention discloses a high-precision current output method and a high-precision constant current source system. The method includes determining the current output value; determining the target current level corresponding to the current output value, wherein different current levels are provided through different branches. By using different branches to provide different current levels, the required hardware cost can be reduced, thereby improving the system's economy; using the analog-to-digital conversion function of the sampling module to sample the load current, and outputting the sampled value to an LCD display screen, the current output value is displayed in real time on the LCD screen, allowing users to easily monitor the current and make necessary adjustments. This invention improves the output accuracy of the constant current source system while reducing costs, minimizing circuit losses, and simplifying the operation process. This invention provides a precise, economical, and efficient current output solution suitable for various applications requiring current control.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit technology, and more specifically, to a high-precision current output method and a high-precision constant current source system required for testing power semiconductor devices. Background Technology

[0002] Constant current source technology has many applications in the field of electronic engineering. This technology is mainly used to ensure that the current in a circuit remains constant, unaffected by external factors.

[0003] One existing technology provides a simple method for implementing a constant current source: by connecting a resistor to a stable voltage source, a constant current output can be achieved according to Ohm's law. However, this method is sensitive to load variations and is therefore typically used in smaller applications, especially in the field of high-precision semiconductors.

[0004] In addition, a current mirror is a common constant current source used in electronic circuits. However, the performance of a current mirror is usually highly dependent on temperature stability and has a high voltage drop, which can easily cause heat generation.

[0005] In addition, an existing technology provides a method using an open-loop control circuit. However, these methods are generally unsuitable for applications requiring high precision, with large load variations, or with highly variable environmental conditions.

[0006] The existing high-precision constant current source circuits mentioned above offer good solutions, but each has its own shortcomings. Summary of the Invention

[0007] This invention provides a high-precision current output method and a high-precision constant current source system, which at least solves the technical problems in related technologies where high-precision constant current sources are difficult to adjust due to complex structures and sensitivity to load changes, and cannot keep the current constant in the circuit without being affected by external factors.

[0008] According to one aspect of the present invention, a high-precision current output method is provided, comprising the following steps:

[0009] Step 1: Initialize the current output chip in the current output module;

[0010] Step 2: Determine the different current output levels of the current output module;

[0011] Step 3: Perform feedback and self-calibration on the current output module;

[0012] Step 4: Determine the current output value, where the current output value is the actual current value required by the load;

[0013] Step 5: Determine the different current levels corresponding to the required current value, where different current levels are provided by different control branches;

[0014] Step 6: Respond to the user's input operation and change the current of the control branch through the control module;

[0015] Step 7: Use the analog-to-digital conversion function of the sampling module to sample the current of the control branch and output the sampled value to the LCD display screen. The current output value is displayed in real time on the LCD display screen.

[0016] Furthermore, the initialization of the current output chip in the current output module includes: determining the variables of the current output chip after the current output module is powered on, wherein the variables include at least: the coefficients of the function in the chip, the value of the register in the chip, and the state of the register in the chip; and modifying the variables to their initial values.

[0017] Furthermore, the control module changes the current in the control branch, including: responding to user input operations, where the input operations are operations performed on the current output module; and identifying the input operations to obtain the current output value.

[0018] Furthermore, before determining the different current levels corresponding to the current output value, the process also includes: determining the different current output levels of the current output module; and dividing the current output value to obtain multiple current output levels of the current output module.

[0019] Furthermore, different current output levels corresponding to the current output value are determined, including: determining the minimum and maximum current values ​​of the current output value; matching the minimum and maximum current values ​​with multiple current output levels to obtain the current output level.

[0020] Furthermore, the current output module is calibrated; wherein, calibrating the current output module includes: determining the minimum value of the current output value; and setting the minimum value as zero to perform zero-point calibration on the current output module.

[0021] Furthermore, after determining the minimum value of the current output module as zero to perform zero-point calibration on the current output module, the method also includes: determining the maximum value of the current output level; and determining the maximum value as the maximum current value that the current output module can output when it is working normally.

[0022] This invention also proposes a high-precision constant current source system, comprising:

[0023] The current output module is used to output different current output values. The different current output values ​​are obtained according to the current required by the load to obtain different current output levels. The current required by the load to operate is the current output value of the current output module.

[0024] The sampling module is used to acquire the current values ​​of different control branches. These different control branch current values ​​are selected from multiple current output levels, which are predetermined based on different load current requirements.

[0025] The control module is used to control the current of different control branches;

[0026] The display unit is used to display the required current value of the load, wherein the required current value of the load is the sum of the current values ​​of different control branches.

[0027] Optionally, the sampling module is used to acquire the load current values ​​of different branches of the constant current source load circuit. The load current values ​​of different branches are selected from multiple current levels, which are predetermined according to different load current requirements. The sampling is performed by a microcontroller using AD sampling.

[0028] Optionally, AD sampling is performed by the microcontroller of the sampling module, including: using a microcontroller (e.g., 16-bit) for high-precision AD sampling; sending the collected voltage value to the microcontroller; and the microcontroller processing the voltage value and calculating it into a current value for display by the display module.

[0029] Optionally, the display module includes: an LCD display screen for displaying the sampled current value, which can also be directly connected to a host computer for data transmission and display; and a storage chip for storing the values ​​sampled by the microcontroller.

[0030] The control module of this high-precision constant current source includes: using different buttons to change the current value of the control branch.

[0031] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program.

[0032] According to another aspect of the present invention, a processor is also provided for running a program.

[0033] In this embodiment of the invention, a current output value is determined, wherein the current output value is the actual current value required by the load; different current levels corresponding to the required current value are determined, wherein different current levels are provided by different control branches; before outputting the current value, the method further includes: initializing the current output chip in the current output system; wherein initializing the current output chip in the current output system involves determining, after the current output system is powered on, the variables of the current output chip are acquired, wherein the variables include at least: coefficients of functions in the chip, values ​​of registers in the chip, and states of registers in the chip; the variables are then modified to their initial values. A stable current value is output in response to user input operations, where the input operations are operations performed on the current output system; the input operations are identified to obtain the output current.

[0034] This invention provides a high-precision current output method and a high-precision constant current source system, addressing at least the technical problems of high-precision constant current sources in related technologies, such as cumbersome structure, sensitivity to load changes leading to current fluctuations, difficulty in adjustment, and inability to maintain a constant current in the circuit unaffected by external factors. This invention improves the output accuracy of the constant current source while reducing costs, minimizing circuit losses, and simplifying operation. This invention provides a precise, economical, and efficient current output solution suitable for various applications requiring current control. Attached Figure Description

[0035] Figure 1 This is a hardware structure block diagram of a constant current source system for a high-precision current output method according to an embodiment of the present invention;

[0036] Figure 2 This is an operation flowchart of the present invention;

[0037] Figure 3 This is a circuit diagram of the constant current source circuit in this invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] As described in the background section, related technologies suffer from drawbacks such as constant current sources being highly susceptible to load fluctuations and having complex hardware wiring. This invention provides a high-precision current output method, a high-precision constant current source, and a processor in its embodiments.

[0040] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0041] The methods and embodiments provided in this invention can be executed on a mobile terminal, a computer terminal, or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a constant current source system for a high-precision current output method according to an embodiment of the present invention. Figure 1 As shown, it includes buttons, an LCD display, a current output module, a sampling module, a control module, a display module, and a constant current source circuit.

[0042] The buttons are used to send control information to the control module;

[0043] The LCD screen is used to display the current of the load circuit.

[0044] The current output module is used to output voltage to different control branches;

[0045] The sampling module is used to sample the current of different control branches;

[0046] The control module is used to control the current of different control branches;

[0047] The display module is used to display the real-time current.

[0048] A constant current source circuit is used to provide a constant current;

[0049] like Figure 1 As shown, the constant current source system may include one or more ( Figure 1 Only one processor is shown in the diagram (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.). The constant current source system described above may also include transmission devices for communication functions and input / output devices. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the constant current source system described above. For example, the constant current source system may also include components that are more powerful than... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0050] According to an embodiment of the present invention, a method embodiment of a high-precision current output method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0051] Figure 2 This is an operation flowchart of an optional constant current source system according to an embodiment of the present invention, such as... Figure 2As shown, the system is powered on, providing power for normal operation; system initialization ensures stability and reliability; sampling branch calibration measures the resistance of the sampling branch to prevent variations in resistance from affecting the control branch current; the control branch current is controlled via buttons, and the actual load current displayed on the screen is observed. If the actual load current differs significantly from the user's expected current, the high-resolution control branch is adjusted; if the difference is small, the low-resolution control branch is adjusted. The low-resolution control branch allows for smaller adjustments compared to the high-resolution control branch, but its adjustable range is smaller. After powering on the constant current source system, initialization can be performed to determine the output accuracy of the current output module.

[0052] In this embodiment, the user can input the desired current value via a physical button after the system is powered on; the current output module will recognize the input operation after sensing it and then adjust the current value accordingly.

[0053] By subdividing the resolution of the control branch current, the output range selection can be made closer to the required current value, thereby improving the accuracy of the current output.

[0054] In this embodiment, the minimum and maximum current values ​​of the current output can be compared with the maximum and minimum values ​​of each current output value in multiple current output channels to select the current output range with the smallest difference as the target current output range, thereby improving output accuracy.

[0055] According to the above embodiments of the present invention, the high-precision current output method further includes: calibrating the current output module; wherein, calibrating the current output module includes: different control branches providing the same voltage value, and monitoring whether the current of different control branches conforms to the ratio.

[0056] According to the above embodiments of the present invention, the high-precision current output method further includes: using a feedback circuit to control the load current, including: an operational amplifier clamping the control branch voltage; and a switching transistor switching on and off through the operational amplifier to regulate the load current.

[0057] In this embodiment, AD sampling adopts an interval sampling and averaging method to improve the accuracy of AD sampling.

[0058] Figure 3This is the circuit diagram of the constant current source circuit in this invention. Resistors RX1 and RX2 are sampling resistors. The branches containing resistors RX1 and RX2 are different control branches. The processor outputs voltage U to the operational amplifier 3 terminal. According to the virtual short principle of an ideal operational amplifier, the output of operational amplifier 2 terminal is the same voltage U as that of operational amplifier 3 terminal. According to Ohm's law, the current I1 or I2 flowing through resistor RX1 or resistor RX2 is U / RX1 or U / RX2. The operational amplifier and MOSFET form a feedback circuit. By controlling the switching of the MOSFET through the operational amplifier, the current fluctuation of the control branch is adjusted to ensure the stability of the current in different control branches. U0 provides power to the constant current source circuit. The remaining resistors in the circuit are current-limiting resistors and protection circuits.

[0059] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-precision current output method, characterized in that, Includes the following steps: Step 1: Initialize the current output chip in the current output module; Step 2: Determine the different current output levels of the current output module; Step 3: Perform feedback and self-calibration on the current output module; Step 4: Determine the current output value, where the current output value is the actual current value required by the load; Step 5: Determine the different current levels corresponding to the required current value, where different current levels are provided by different control branches; Step 6: Respond to the user's input operation and change the current of the control branch through the control module; Step 7: Use the analog-to-digital conversion function of the sampling module to sample the current of the control branch and output the sampled value to the LCD display screen. The current output value is displayed in real time on the LCD display screen.

2. The high-precision current output method according to claim 1, characterized in that, in, Initialize the current output chip in the current output module, including: after the current output module is powered on, obtain the variables of the current output chip, wherein the variables include at least: the coefficients of the function in the chip, the value of the register in the chip, and the state of the register in the chip; and modify the variables to the initial values.

3. The high-precision current output method according to claim 1, characterized in that, The control module changes the current in the control branch, including: responding to user input operations, where the input operations are operations performed on the current output module; and identifying the input operations to obtain the current output value.

4. The high-precision current output method according to claim 1, characterized in that, Before determining the different current levels corresponding to the current output value, the process also includes: determining the different current output levels of the current output module; and dividing the current output value to obtain multiple current output levels of the current output module.

5. The high-precision current output method according to claim 1, characterized in that, Determine the different current output levels corresponding to the current output value, including: determining the minimum and maximum current values ​​of the current output value; matching the minimum and maximum current values ​​with multiple current output levels to obtain the current output level.

6. The high-precision current output method according to claim 1, characterized in that, Also includes: The current output module is calibrated; the calibration of the current output module includes: determining the minimum value of the current output value; and setting the minimum value as the zero point to perform zero-point calibration of the current output module.

7. The high-precision current output method according to claim 1, characterized in that, After determining the minimum value of the current output module as zero to perform zero-point calibration on the current output module, the following steps are also included: determining the maximum value of the current output level; and setting the maximum value as the maximum current value that the current output module can output when it is working normally.

8. A high-precision constant current source system, characterized in that, include: The current output module is used to output different current output values. The different current output values ​​are obtained according to the current required by the load to obtain different current output levels. The current required by the load to operate is the current output value of the current output module. The sampling unit is used to acquire different control branch current values, wherein the different control branch current values ​​are selected from multiple current output levels, which are predetermined according to different load current requirements. The control module is used to control the current of different control branches; The display unit is used to display the required current value of the load, wherein the required current value of the load is the sum of the current values ​​of different control branches.

9. A processor, characterized in that, The processor is used to run a program, wherein the program executes the high-precision current output method of any one of claims 1 to 7.

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