A charge pump step-down constant current circuit controlled by a DSP and a control method thereof

Abstract

This invention discloses a DSP-controlled charge pump step-down constant current circuit and its control method, comprising a charge pump module, a current detection module, a feedback loop module, and a DSP control module. The current detection module includes a charging current detection module, a voltage detection module, and a drive module. The feedback loop module includes a voltage divider, a current sensing resistor, a comparator, and an error amplifier. This invention, through the current detection module, feedback loop module, DSP control module, protection mechanism module, and soft-start function, realizes a DSP-controlled charge pump step-down constant current circuit, enabling it to achieve high-precision constant current output. Through real-time calculation and adjustment by the DSP, high-precision control of the output current and voltage is achieved, maintaining current and voltage stability even under load fluctuations. The adaptive frequency control strategy optimizes energy conversion efficiency, reduces energy consumption, and improves flexibility and scalability.

Description

Technical Field

[0001] This invention relates to the field of charge pump technology, specifically to a DSP-controlled charge pump step-down constant current circuit and its control method. Background Technology

[0002] Charge pumps, also known as switched-capacitor voltage converters, are a type of circuit that utilizes digital signal processing (DSP), a technology for processing and analyzing digital signals. DSP involves signal acquisition, transformation, filtering, and encoding. While traditional charge pump buck converters can achieve voltage conversion, they often lack precise current control, particularly exhibiting significant output current fluctuations under varying loads. Furthermore, most existing technologies rely on complex feedback circuits and analog controllers, increasing system cost and design complexity.

[0003] To this end, we provide a charge pump step-down constant current circuit with DSP control and its control method. Summary of the Invention

[0004] The purpose of this invention is to provide a charge pump step-down constant current circuit and its control method using DSP control, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a charge pump step-down constant current circuit controlled by DSP, comprising a charge pump module, a current detection module, a feedback loop module and a DSP control module, wherein the current detection module comprises a charging current detection module, a voltage detection module and a drive module, and the feedback loop module comprises a voltage divider, a current detection resistor, a comparator and an error amplifier;

[0006] The charging current detection module is used to copy and detect the charging current. It can accurately copy the charging current and feed the charging current signal back to the comparator to form a charging loop. The copied current is usually 1 / 10000 of the charging current in order to perform accurate current detection.

[0007] The voltage detection module is used to detect the voltage state on the external capacitor. When the voltage on the external capacitor is greater than the preset upper limit value, it outputs a high level, turns off the oscillator module, and controls the output stage to output a high level, thereby turning on the power transistor.

[0008] The driver module is used to drive large-area power transistors, ensuring the magnitude and stability of the current.

[0009] A voltage divider is used to reduce the input voltage, providing the required lower voltage level for the charge pump module;

[0010] The current sensing resistor is used to measure the current in the circuit, and can also protect the circuit and control the working state of the charge pump module.

[0011] A comparator is used to compare the difference between the actual output and the desired output and convert this difference into a control signal. At the same time, the comparator monitors the output voltage or current and compares it with the set value, thereby adjusting the control signal of the switch to maintain the stability of the output.

[0012] An error amplifier is used to amplify the error signal output by the comparator, giving it sufficient driving force to control the switching on and off.

[0013] The DSP control module employs a DSP control algorithm. This algorithm acquires signals from the current detection module, calculates the deviation from the set current value in real time, and dynamically adjusts the switching control signal of the charge pump module based on a PID control algorithm to achieve closed-loop control of the output current. The DSP control module includes a protection mechanism module. The DSP monitors the output current or voltage of the charge pump circuit to determine load changes. When the load becomes lighter, the DSP reduces the switching frequency to decrease switching losses; when the load becomes heavier, it increases the switching frequency to ensure a stable output voltage or current. The DSP adjusts the switching frequency by calculating circuit efficiency and by monitoring circuit temperature to compensate for the temperature's influence on circuit parameters.

[0014] Preferably, the charge pump module includes a switching element, a capacitor element, and a voltage source. The switching element consists of a transistor, a relay, and a diode, and the capacitor element consists of a fly capacitor and an output voltage regulator capacitor.

[0015] Preferably, the protection mechanism module includes an overcurrent protection module, an overvoltage protection module, a temperature protection module, a short circuit protection module, an undervoltage protection module, and a software protection module.

[0016] Preferably, the overcurrent protection module monitors the current value in the circuit in real time through the DSP and compares it with a preset threshold. Once the current exceeds the threshold, the DSP will immediately trigger the protection mechanism, thereby reducing the output voltage or completely cutting off the power supply to prevent damage caused by excessive current. The overvoltage protection module monitors the output voltage of the circuit through the DSP to ensure that it remains within a safe range. The temperature protection module monitors the temperature of the circuit in real time through the DSP. The short-circuit protection module quickly cuts off the power supply through the DSP to prevent short-circuit current from damaging the circuit. The undervoltage protection module shuts down the circuit or adjusts the output voltage through the DSP to ensure that the circuit operates within the normal operating range. The software protection prevents circuit abnormalities caused by program errors or external interference. A watchdog timer is set to monitor the program's running status. Once the program malfunctions, the DSP is immediately reset.

[0017] Preferably, the DSP control module includes a soft-start function to gradually increase the current to a preset value, protecting the circuit from startup shock.

[0018] A control method for a DSP-controlled charge pump step-down constant current circuit, the control method being applicable to the aforementioned DSP-controlled charge pump step-down constant current circuit, specifically including the following methods:

[0019] S1. Initialization Configuration: Configure the DSP's clock, interrupts, and I / O ports to prepare for the control of the charge pump module, and initialize the ADC register in the charge pump circuit for reading voltage or current values.

[0020] S2. Voltage and Current Control Algorithm: Write a control algorithm to adjust the output voltage or current of the charge pump module. This can be achieved through a PID control algorithm. The DSP's PWM module sends control signals to the charge pump module to adjust the on-time and duty cycle of the switching elements, thereby achieving voltage or current control.

[0021] S3. DSP control program performs PID parameter tuning: The operation is carried out by trial and error. Initially, a small KP value is set to avoid system oscillation. Then, the KP value is gradually increased until the system response speed becomes faster but oscillation begins to occur. At this time, the KP value should be appropriately reduced and integral action should be added to eliminate steady-state error. Finally, derivative action should be added to further improve the stability of the system.

[0022] S4. Monitoring the status of the protection mechanism module: The DSP's ADC module is used to periodically read various data in the protection mechanism module to monitor the circuit's operating status and implement overvoltage and overcurrent protection mechanisms. At the same time, the DSP monitors various data in the current detection module and feedback loop module. When an abnormal signal occurs, the DSP should immediately adjust the control signal or even shut down the charge pump circuit to prevent damage.

[0023] S5. DSP Adaptive Frequency Adjustment: The DSP judges the load change by monitoring the output current or voltage of the charge pump circuit. When the load becomes lighter, the DSP reduces the switching frequency to reduce switching losses. When the load becomes heavier, the switching frequency is increased to ensure a stable output voltage or current. The DSP adjusts the switching frequency by calculating the efficiency of the circuit. The DSP adjusts the switching frequency by monitoring the temperature of the circuit to compensate for the effect of temperature on the circuit parameters.

[0024] S6. Debugging and Testing: Add debugging and testing code to the control program to verify the circuit's functionality and performance. Use a JTAG debugger to monitor and control program execution for troubleshooting and optimization.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention implements a DSP-controlled charge pump step-down constant current circuit through a current detection module, feedback loop module, DSP control module, protection mechanism module, and soft-start function. This circuit provides high-precision constant current output, achieving high-precision control of output current and voltage through real-time calculation and adjustment by the DSP. Even under load fluctuations, current and voltage stability are maintained. The adaptive frequency control strategy optimizes energy conversion efficiency, reduces energy consumption, and improves flexibility and scalability. The DSP's programming flexibility allows users to adjust the control strategy according to needs, facilitating upgrades and function expansion. Enhanced system stability and protection are achieved, and the built-in protection mechanism effectively extends the lifespan of the circuit and load. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the circuit framework of the present invention;

[0028] Figure 2 This is a schematic diagram illustrating the control principle of the present invention;

[0029] Figure 3 This is a schematic diagram of the control principle of the current detection module of the present invention;

[0030] Figure 4 This is a schematic diagram of the control principle of the feedback loop module of the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0032] Please see Figure 1-4 A charge pump step-down constant current circuit controlled by DSP includes a charge pump module, a current detection module, a feedback loop module and a DSP control module. The current detection module includes a charging current detection module, a voltage detection module and a drive module. The feedback loop module includes a voltage divider, a current detection resistor, a comparator and an error amplifier.

[0033] The charging current detection module is used to replicate and detect the charging current. It can accurately replicate the charging current and feed the charging current signal back to the comparator to form a charging loop. The replicated current is usually 1 / 10000 of the charging current in order to perform accurate current detection.

[0034] The voltage detection module is used to detect the voltage state on the external capacitor. When the voltage on the external capacitor is greater than the preset upper limit, it outputs a high level, turns off the oscillator module, and controls the output stage to output a high level, thereby turning on the power transistor.

[0035] The driver module is used to drive large-area power transistors, ensuring the magnitude and stability of the current.

[0036] A voltage divider is used to reduce the input voltage, providing the required lower voltage level for the charge pump module.

[0037] A current sensing resistor is used to measure the current in a circuit, while also protecting the circuit and controlling the operation of the charge pump module.

[0038] A comparator is used to compare the difference between the actual output and the desired output and convert this difference into a control signal. At the same time, the comparator monitors the output voltage or current and compares it with the set value, thereby adjusting the control signal of the switch to maintain the stability of the output.

[0039] An error amplifier is used to amplify the error signal output by the comparator, giving it sufficient driving force to control the switching on and off.

[0040] The DSP control module employs a DSP control algorithm. This algorithm acquires signals from the current detection module, calculates the deviation from the set current value in real time, and dynamically adjusts the switching control signal of the charge pump module based on a PID control algorithm to achieve closed-loop control of the output current. The DSP control module also includes a protection mechanism module.

[0041] The charge pump module includes a switching element, a capacitor element, and a voltage source. The switching element consists of a transistor, a relay, and a diode, and the capacitor element consists of a fly capacitor and an output voltage regulator capacitor.

[0042] The protection mechanism module includes an overcurrent protection module, an overvoltage protection module, a temperature protection module, a short-circuit protection module, an undervoltage protection module, and a software protection module. The overcurrent protection module monitors the current value in the circuit in real time through the DSP and compares it with a preset threshold. Once the current exceeds the threshold, the DSP will immediately trigger the protection mechanism, thereby reducing the output voltage or completely cutting off the power supply to prevent damage caused by excessive current. The overvoltage protection module monitors the output voltage of the circuit through the DSP to ensure that it remains within a safe range. The temperature protection module monitors the temperature of the circuit in real time through the DSP. The short-circuit protection module quickly cuts off the power supply through the DSP to prevent short-circuit current from damaging the circuit. The undervoltage protection module shuts down the circuit or adjusts the output voltage through the DSP to ensure that the circuit operates within the normal operating range. The software protection prevents circuit abnormalities caused by program errors or external interference. A watchdog timer is set to monitor the program's running status. Once a program abnormality occurs, the DSP is immediately reset.

[0043] The DSP control module includes a soft-start function, which is used to gradually increase the current to a preset value to protect the circuit from startup shock.

[0044] A control method for a DSP-controlled charge pump step-down constant current circuit, the method being applicable to DSP-controlled charge pump step-down constant current circuits, specifically including the following methods:

[0045] S1. Initialization Configuration: Configure the DSP's clock, interrupts, and I / O ports to prepare for the control of the charge pump module. Initialize the ADC register in the charge pump circuit to read voltage or current values.

[0046] S2. Voltage and Current Control Algorithm: Write a control algorithm to adjust the output voltage or current of the charge pump module. This can be achieved through a PID control algorithm. The DSP's PWM module sends control signals to the charge pump module to adjust the on-time and duty cycle of the switching elements, thereby achieving voltage or current control.

[0047] S3. DSP control program performs PID parameter tuning: The operation adopts an empirical trial-and-error method. Initially, a small KP value is set to avoid system oscillation. Then, the KP value is gradually increased until the system response speed becomes faster but oscillation begins to occur. At this point, the KP value should be appropriately reduced, and integral action should be added to eliminate steady-state error. Finally, derivative action should be added to further improve the stability of the system.

[0048] S4. Monitoring the status of the protection mechanism module: The DSP's ADC module is used to periodically read various data in the protection mechanism module to monitor the circuit's operating status and implement overvoltage and overcurrent protection mechanisms. At the same time, the DSP monitors various data in the current detection module and feedback loop module. When an abnormal signal occurs, the DSP should immediately adjust the control signal or even shut down the charge pump circuit to prevent damage.

[0049] S5. DSP Adaptive Frequency Adjustment: The DSP judges the load change by monitoring the output current or voltage of the charge pump circuit. When the load becomes lighter, the DSP reduces the switching frequency to reduce switching losses. When the load becomes heavier, the switching frequency is increased to ensure a stable output voltage or current. The DSP adjusts the switching frequency by calculating the efficiency of the circuit. The DSP adjusts the switching frequency by monitoring the temperature of the circuit to compensate for the effect of temperature on the circuit parameters.

[0050] Furthermore, the DSP automatically adjusts the operating frequency of the charge pump based on load changes to optimize efficiency and response speed while reducing electromagnetic interference.

[0051] S6. Debugging and Testing: Add debugging and testing code to the control program to verify the circuit's functionality and performance. Use a JTAG debugger to monitor and control program execution for troubleshooting and optimization.

[0052] By leveraging the high-performance computing capabilities and flexible programming features of the DSP, precise control of the charge pump step-down circuit can be achieved to obtain constant current output.

[0053] This paper presents a DSP-controlled charge pump step-down constant current circuit with high-precision constant current output, implemented through a current detection module, feedback loop module, DSP control module, protection mechanism module, and soft-start function. The circuit achieves high-precision control of output current and voltage through real-time calculation and adjustment by the DSP, maintaining current and voltage stability even under load fluctuations. The adaptive frequency control strategy optimizes energy conversion efficiency, reduces energy consumption, and improves flexibility and scalability. The DSP's programming flexibility allows users to adjust the control strategy according to their needs, facilitating upgrades and function expansion. Enhanced system stability and protection are achieved through a built-in protection mechanism that effectively extends the lifespan of the circuit and load.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A charge pump step-down constant current circuit controlled by a DSP, characterized in that: It includes a charge pump module, a current detection module, a feedback loop module, and a DSP control module. The current detection module includes a charging current detection module, a voltage detection module, and a drive module. The feedback loop module includes a voltage divider, a current detection resistor, a comparator, and an error amplifier. The charging current detection module is used to copy and detect the charging current. It can accurately copy the charging current and feed the charging current signal back to the comparator to form a charging loop. The copied current is usually 1 / 10000 of the charging current in order to perform accurate current detection. The voltage detection module is used to detect the voltage state on the external capacitor. When the voltage on the external capacitor is greater than the preset upper limit value, it outputs a high level, turns off the oscillator module, and controls the output stage to output a high level, thereby turning on the power transistor. The driver module is used to drive large-area power transistors, ensuring the magnitude and stability of the current. A voltage divider is used to reduce the input voltage, providing the required lower voltage level for the charge pump module; The current sensing resistor is used to measure the current in the circuit, and can also protect the circuit and control the working state of the charge pump module. A comparator is used to compare the difference between the actual output and the desired output and convert this difference into a control signal. At the same time, the comparator monitors the output voltage or current and compares it with the set value, thereby adjusting the control signal of the switch to maintain the stability of the output. An error amplifier is used to amplify the error signal output by the comparator, giving it sufficient driving force to control the switching on and off. The DSP control module employs a DSP control algorithm. This algorithm acquires signals from the current detection module, calculates the deviation from the set current value in real time, and dynamically adjusts the switching control signal of the charge pump module based on a PID control algorithm to achieve closed-loop control of the output current. The DSP control module includes a protection mechanism module. The DSP monitors the output current or voltage of the charge pump circuit to determine load changes. When the load becomes lighter, the DSP reduces the switching frequency to decrease switching losses; when the load becomes heavier, it increases the switching frequency to ensure a stable output voltage or current. The DSP adjusts the switching frequency by calculating circuit efficiency and by monitoring circuit temperature to compensate for the temperature's influence on circuit parameters.

2. The charge pump step-down constant current circuit using DSP control according to claim 1, characterized in that: The charge pump module includes a switching element, a capacitor element, and a voltage source. The switching element consists of a transistor, a relay, and a diode, and the capacitor element consists of a fly capacitor and an output voltage regulator capacitor.

3. The charge pump step-down constant current circuit using DSP control according to claim 2, characterized in that: The protection mechanism module includes an overcurrent protection module, an overvoltage protection module, a temperature protection module, a short circuit protection module, an undervoltage protection module, and a software protection module.

4. The charge pump step-down constant current circuit using DSP control according to claim 3, characterized in that: The overcurrent protection module monitors the current value in the circuit in real time through the DSP and compares it with a preset threshold. Once the current exceeds the threshold, the DSP will immediately trigger the protection mechanism, thereby reducing the output voltage or completely cutting off the power supply to prevent damage caused by excessive current. The overvoltage protection module monitors the output voltage of the circuit through the DSP to ensure that it remains within a safe range. The temperature protection module monitors the temperature of the circuit in real time through the DSP. The short-circuit protection module quickly cuts off the power supply through the DSP to prevent short-circuit current from damaging the circuit. The undervoltage protection module shuts down the circuit or adjusts the output voltage through the DSP to ensure that the circuit operates within the normal operating range. The software protection prevents circuit abnormalities caused by program errors or external interference. A watchdog timer is set to monitor the program's running status. Once a program abnormality occurs, the DSP is immediately reset.

5. The charge pump step-down constant current circuit using DSP control according to claim 4, characterized in that: The DSP control module includes a soft-start function, which is used to gradually increase the current to a preset value to protect the circuit from startup shock.

6. A control method for a charge pump step-down constant current circuit using DSP control, characterized in that, The control method is applicable to the DSP-controlled charge pump step-down constant current circuit described in any one of claims 1-5, and specifically includes the following methods: S1. Initialization Configuration: Configure the DSP's clock, interrupts, and I / O ports to prepare for the control of the charge pump module, and initialize the ADC register in the charge pump circuit for reading voltage or current values. S2. Voltage and Current Control Algorithm: Write a control algorithm to adjust the output voltage or current of the charge pump module. This can be achieved through a PID control algorithm. The DSP's PWM module sends control signals to the charge pump module to adjust the on-time and duty cycle of the switching elements, thereby achieving voltage or current control. S3. DSP control program performs PID parameter tuning: The operation is carried out by trial and error. Initially, a small KP value is set to avoid system oscillation. Then, the KP value is gradually increased until the system response speed becomes faster but oscillation begins to occur. At this time, the KP value should be appropriately reduced and integral action should be added to eliminate steady-state error. Finally, derivative action should be added to further improve the stability of the system. S4. Monitoring the status of the protection mechanism module: The DSP's ADC module is used to periodically read various data in the protection mechanism module to monitor the circuit's operating status and implement overvoltage and overcurrent protection mechanisms. At the same time, the DSP monitors various data in the current detection module and feedback loop module. When an abnormal signal occurs, the DSP should immediately adjust the control signal or even shut down the charge pump circuit to prevent damage. S5. DSP Adaptive Frequency Adjustment: The DSP judges the load change by monitoring the output current or voltage of the charge pump circuit. When the load becomes lighter, the DSP reduces the switching frequency to reduce switching losses. When the load becomes heavier, the switching frequency is increased to ensure a stable output voltage or current. The DSP adjusts the switching frequency by calculating the efficiency of the circuit. The DSP adjusts the switching frequency by monitoring the temperature of the circuit to compensate for the effect of temperature on the circuit parameters. S6. Debugging and Testing: Add debugging and testing code to the control program to verify the circuit's functionality and performance. Use a JTAG debugger to monitor and control program execution for troubleshooting and optimization.

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