Overcurrent protection circuit for GaN servo driver
The GaN servo driver overcurrent protection circuit, which integrates a current sampling module and a resistor voltage divider module, solves the problems of slow response, complexity, and low accuracy of traditional circuits, and achieves fast and accurate overcurrent protection, ensuring safe and reliable circuit operation.
Patent Information
- Application Number
- CN202520102018.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-01-16
AI Technical Summary
Traditional GaN servo driver overcurrent protection circuits have slow response speed, complex circuitry, low precision, and poor reliability. They cannot protect devices in a timely manner, and they consume a lot of power in battery-powered applications and are easily affected by temperature and noise.
It employs a current sampling module, a resistor voltage divider module, an overcurrent signal output module, and an overcurrent signal reset module, combined with a current sampling chip, to achieve high-precision current sampling and flexible overcurrent protection threshold setting, quickly respond and shut down the power switch, and has anti-interference capabilities and a reliable reset mechanism.
It achieves fast and accurate overcurrent protection, reduces circuit size and cost, improves circuit stability and safety, and adapts to the needs of different application scenarios.
Smart Images
Figure CN223898963U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of overcurrent protection, and particularly relates to an overcurrent protection circuit for a GaN servo driver. BACKGROUND
[0002] With the rapid development of power electronic technology, GaN (gallium nitride) devices have gradually begun to be applied in power electronic equipment such as servo drivers due to their high efficiency, low power consumption and fast switching characteristics. However, these devices may encounter overcurrent conditions during operation, which may cause damage to the devices themselves and the entire system. Therefore, the design of the overcurrent protection circuit is particularly important.
[0003] At present, traditional overcurrent protection circuits generally use discrete components such as current detection resistors, operational amplifiers, comparators, etc. Although these circuits can achieve the function of overcurrent protection to some extent, when an overcurrent event occurs, the response speed of the traditional protection circuit is not fast enough, and the device may not be protected in time; the use of multiple discrete components leads to complex circuit, increased volume, and is not conducive to system integration; due to the large number of components, the accuracy and reliability of the circuit are affected to a certain extent.
[0004] The traditional circuit usually has high offset voltage, drift and gain error, resulting in low current measurement accuracy; the signal bandwidth and slew rate of the traditional circuit are usually low, resulting in slow response speed of the overcurrent protection; the traditional circuit needs to use multiple discrete components, leading to complex circuit design, increasing the number of components and the circuit board space; the traditional circuit is difficult to debug and needs to carefully adjust the parameters of each component; the power consumption of the traditional circuit is usually high, which is a problem for battery-powered applications; due to the use of multiple discrete components, the reliability of the traditional circuit is low and it is more susceptible to temperature, noise and other factors. CONTENT OF THE INVENTION
[0005] The purpose of the present application is to provide an overcurrent protection circuit for a GaN servo driver, which provides comprehensive overcurrent protection for the GaN servo driver and ensures its safe and stable operation under various working conditions.
[0006] In order to achieve the above purpose, the embodiments of the present application provide an overcurrent protection circuit for a GaN servo driver, comprising:
[0007] a current sampling module, a resistance voltage division module, an overcurrent signal output module, an overcurrent signal reset module and a current sampling chip, wherein
[0008] The current sampling module is connected with the overcurrent signal output module through the current sampling chip, and is used for sampling the current between the power input and the power output, and converting the current signal into a voltage signal through resistance voltage division;
[0009] The resistance voltage division module is connected with the overcurrent signal output module through the current sampling chip, and is used for setting a threshold of overcurrent protection.
[0010] The overcurrent signal output module is connected with the current sampling module, the resistance voltage division module and the overcurrent signal reset module through the current sampling chip, and is used for outputting a signal to close the power switch when detecting an overcurrent condition.
[0011] The overcurrent signal reset module is connected with the overcurrent signal output module through the current sampling chip, and is used for resetting the overcurrent protection signal.
[0012] According to the method provided in the embodiment of the application, the following additional technical features can be further included.
[0013] Further, the current sampling module includes a resistor R21, a resistor R22, a resistor R24, a capacitor C54 and a capacitor C55, wherein,
[0014] One end of the resistor R21 is connected to a power input, and is connected to the 8th pin of the current sampling chip after being connected with the resistor R22, and the other end is connected to a power output and is connected to the 7th pin of the current sampling chip after being connected with the resistor R24;
[0015] The capacitor C54 is connected between the 8th pin and the 7th pin of the current sampling chip, and is used for filtering a sampling signal input; and the capacitor C55 is connected between the 1st pin and the 4th pin of the current sampling chip, and is used for filtering a power input.
[0016] Further, the resistance voltage division module includes a resistor R23 and a resistor R25, wherein,
[0017] One end of the resistor R23 is connected to the 2nd pin of the current sampling chip, and the other end is connected to the 3rd pin of the current sampling chip; and one end of the resistor R25 is connected to the 3rd pin of the current sampling chip, and the other end is connected to the ground.
[0018] Further, the overcurrent signal output module includes a resistor R31, wherein,
[0019] The 6th pin of the current sampling chip is connected to a 3.3V power supply through the resistor R31, and a signal is output to the / OCL_O network.
[0020] Further, the overcurrent signal reset module is connected to the 5th pin of the current sampling chip, and a low-level signal is sent to the current sampling chip by the overcurrent signal reset module when it is needed to reset the overcurrent signal.
[0021] Compared with the prior art, the high-performance overcurrent protection circuit for the GaN servo driver provided in the embodiment of the application has the following beneficial technical effects:
[0022] The current sampling module in this embodiment samples the current between the power input and output through high-precision resistors (R21, R22, R24), and converts the current signal into a voltage signal through resistor voltage division. This conversion is not only accurate, but also reflects the changes in current in real time, providing a reliable data basis for subsequent overcurrent protection.
[0023] The resistor divider module (including R23 and R25) in this embodiment allows users to set the overcurrent protection threshold according to actual needs. By adjusting the resistance values of these two resistors, the output voltage of the voltage divider network can be easily changed, thereby achieving precise control of the overcurrent protection threshold. This flexibility enables the circuit to adapt to the overcurrent protection requirements of different application scenarios.
[0024] When an overcurrent signal output module of this application detects an overcurrent condition, it can quickly output a signal to shut down the power switch, thereby effectively cutting off the current path and protecting the circuit from damage. At the same time, the overcurrent signal reset module allows the overcurrent protection signal to be reset when needed, so that the circuit can return to normal operation. This reliable overcurrent protection mechanism ensures the stability and safety of the circuit.
[0025] In this embodiment, capacitors C54 and C55 are used for filtering the sampling signal input and power input, respectively, effectively filtering out high-frequency noise and interference signals, improving the circuit's anti-interference capability and stability. This excellent filtering performance enables the circuit to work stably in harsh electromagnetic environments. Attached Figure Description
[0026] Figure 1 A structural block diagram of a high-performance overcurrent protection circuit for a GaN servo driver according to an embodiment of this application is shown;
[0027] Figure 2 A schematic diagram of a high-performance overcurrent protection circuit for a GaN servo driver according to an embodiment of this application is shown. Detailed Implementation
[0028] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.
[0029] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.
[0030] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.
[0031] like Figure 1 As shown in the figure, this application embodiment provides an overcurrent protection circuit for a GaN servo driver. This overcurrent protection circuit is specifically designed for GaN servo drivers and aims to provide an effective overcurrent protection mechanism. It mainly consists of a current sampling module, a resistor voltage divider module, an overcurrent signal output module, an overcurrent signal reset module, and a current sampling chip. These modules work together to ensure timely response and circuit protection in the event of an overcurrent.
[0032] The current sampling module is responsible for sampling the current between the power input and output, converting the current signal into a voltage signal, and connecting it to the overcurrent signal output module via a current sampling chip. The sampling process involves resistor voltage division to convert the current signal into a suitable voltage signal for processing.
[0033] The resistor divider module is used to set the overcurrent protection threshold. It is also connected to the overcurrent signal output module via a current sampling chip. The resistor divider module determines the trigger point for overcurrent protection by adjusting the resistance value.
[0034] The overcurrent signal output module outputs a signal to shut down the power switch when an overcurrent condition is detected. It connects to the current sampling module, resistor divider module, and overcurrent signal reset module via a current sampling chip. When the current exceeds a preset threshold, the overcurrent signal output module triggers a signal that shuts down the power switch, thus cutting off the overcurrent path.
[0035] The overcurrent signal reset module is used to reset the overcurrent protection signal. It is connected to the overcurrent signal output module via a current sampling chip. After the overcurrent condition is handled, the overcurrent signal reset module sends a signal to reset the overcurrent protection state, restoring the circuit to normal operation.
[0036] This overcurrent protection circuit achieves a highly integrated design by integrating multiple modules and a current sampling chip, which helps reduce circuit size and cost. The current sampling and overcurrent detection process is rapid, enabling it to detect overcurrent conditions and trigger the protection mechanism in a short time, effectively preventing circuit damage. The resistor divider module allows users to adjust the overcurrent protection threshold as needed, providing flexible configuration options. The use of advanced GaN technology and a reliable overcurrent protection mechanism ensures high reliability and stability of the circuit.
[0037] like Figure 2 As shown, the current sampling module is responsible for sampling the current between the power input and output and converting this current signal into a voltage signal for subsequent processing and judgment. The current sampling module specifically consists of the following components:
[0038] Resistor R21: As the main component for current sampling, one end of R21 is connected to the power input terminal, and the other end is connected to the power output terminal. Simultaneously, to convert the sampled current signal into a voltage signal, R21 is connected in series with resistors R22 and R24, respectively, and then connected to a specific pin of the current sampling chip.
[0039] Resistor R22: After being connected in series with R21, the other end of R22 is connected to pin 8 of the current sampling chip. In this way, when current flows through R21 and R22, a voltage drop proportional to the current will be generated on R22. This voltage drop represents the sampled current signal.
[0040] Resistor R24: Similar to the connection of R21 at the power output terminal, R24 is also connected in series with R21 to pin 7 of the current sampling chip. In this way, a voltage drop proportional to the current will be generated across R24, serving as another sampling signal.
[0041] Capacitor C54: Connected between pins 8 and 7 of the current sampling chip, its main function is to filter out high-frequency noise and interference in the sampling signal, ensuring the accuracy and stability of the sampling signal.
[0042] Capacitor C55: Connected between pins 1 and 4 of the current sampling chip, it serves as a power input filter capacitor. The function of C55 is to smooth the power input voltage and reduce the impact of power fluctuations on the sampling signal.
[0043] When current flows between the power input and output, it flows through resistors R21, R22, and R24 respectively. Since the resistance values are known, the current flowing through R22 and R24 can be calculated by measuring the voltage drop across them. These two current values (or corresponding voltage values) are then sent to a current sampling chip for processing. The current sampling chip uses these two sampled signals, along with the overcurrent protection threshold set by the resistor divider module, to determine whether an overcurrent condition has occurred.
[0044] If an overcurrent condition is detected, the overcurrent signal output module will output a signal to shut off the power switch, thereby protecting the circuit from damage. The overcurrent signal reset module is used to reset the overcurrent protection signal when needed, allowing the circuit to return to normal operation.
[0045] The current sampling module provides an accurate and stable current sampling signal for the overcurrent protection circuit through precise resistor sampling and capacitor filtering, which is a key part to ensure the safe and reliable operation of the circuit.
[0046] like Figure 2 As shown, the main function of the resistor voltage divider module is to set a threshold for overcurrent protection. When the current signal acquired by the current sampling module is converted into a voltage signal, this voltage signal is compared with the threshold voltage generated by the resistor voltage divider module. If the sampled voltage exceeds the threshold voltage, the overcurrent signal output module will be triggered, outputting a signal to shut off the power switch, thereby protecting the circuit from damage.
[0047] Specifically, the resistor divider module is composed of resistors R23 and R25, where,
[0048] Resistor R23: One end is connected to pin 2 of the current sampling chip, and the other end is connected to pin 3 of the same chip. This connection makes resistor R23 part of the voltage divider network, participating in the generation of the threshold voltage.
[0049] Resistor R25: One end of it is also connected to pin 3 of the current sampling chip (sharing a connection point with the other end of resistor R23), while the other end is grounded. The function of resistor R25 is to form a voltage divider circuit together with resistor R23. By adjusting the resistance values of these two resistors, the output voltage of the voltage divider network can be changed, which is the overcurrent protection threshold voltage.
[0050] In a resistor voltage divider circuit, the output voltage (i.e., the threshold voltage) is determined by the input voltage and the resistance values of resistors R23 and R25. Based on Ohm's law and the voltage divider principle, the expression for the threshold voltage can be calculated. Typically, this threshold voltage is set to a safe value to ensure the circuit functions properly under normal conditions and to provide a rapid response and protection against overcurrent.
[0051] The resistor divider module, through resistors R23 and R25, provides a reliable threshold setting mechanism for the overcurrent protection circuit of the GaN servo driver. This mechanism not only enhances the circuit's safety but also improves its response speed and stability. In practical applications, the resistance values of R23 and R25 can be adjusted according to specific requirements to optimize the performance of the overcurrent protection circuit.
[0052] like Figure 2As shown, the overcurrent signal output module is used to respond quickly when the current in the circuit exceeds the preset safety threshold. The module outputs a control signal to turn off the power switch, thereby preventing circuit damage or safety accidents such as fires.
[0053] Specifically, the overcurrent signal output module includes resistor R31, which acts as a pull-up resistor, connecting pin 6 of the current sampling chip to the 3.3V power supply. The pull-up resistor ensures that when pin 6 of the chip outputs a low level, the signal is stably and reliably transmitted to subsequent circuits. Simultaneously, resistor R31 also limits the current, protecting the current sampling chip from excessive current surges.
[0054] Signal output to the / OCL_O network: In addition to connecting to the 3.3V power supply, pin 6 of the current sampling chip also outputs a signal to the / OCL_O network. The / OCL_O network is typically a circuit section used to receive and process overcurrent signals. When an overcurrent signal is received, the / OCL_O network further processes the signal and triggers corresponding protection measures, such as shutting down the power switch.
[0055] The reliability and response speed of the overcurrent signal output module are crucial to the safety of the protection circuit. If the module responds too slowly or the signal transmission is unstable, the power switch may fail to turn off in time, increasing the risk of circuit damage. Therefore, when designing an overcurrent protection circuit, the resistance value of resistor R31 and other related circuit components must be carefully selected to ensure that the module's stability and response speed meet the requirements.
[0056] like Figure 2 As shown, when the current in the circuit exceeds a preset safety threshold, the overcurrent protection mechanism is triggered, causing the power switch to shut off, thus protecting the circuit from damage. However, in some cases, overcurrent protection may be caused by false triggering or other non-fault factors. In this case, the overcurrent signal reset module becomes particularly important, as it allows the power switch to be reactivated by sending a reset signal after confirming that the circuit is safe, restoring the circuit to normal operating status.
[0057] Specifically, the overcurrent signal reset module implements its function by connecting to pin 5 of the current sampling chip. When the overcurrent signal needs to be reset, the reset module sends a low-level signal to the current sampling chip. This signal is recognized by the current sampling chip as a reset command, thereby triggering internal logic to clear the previous overcurrent protection state. Once the overcurrent protection state is cleared, the power switch can be reactivated, and the circuit returns to normal operation.
[0058] The overcurrent signal reset module resets the overcurrent protection state by sending a low-level signal to the current sampling chip, allowing the circuit to resume normal operation after confirming safety. When designing the reset module, factors such as signal stability, safety, and maintainability need to be considered to ensure stable circuit operation and safety.
[0059] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.
[0060] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
Claims
1. An overcurrent protection circuit for a GaN servo driver, characterized in that, It includes a current sampling module, a resistor voltage divider module, an overcurrent signal output module, an overcurrent signal reset module, and a current sampling chip, among which, The current sampling module is connected to the overcurrent signal output module through the current sampling chip. It is used to sample the current between the power input and the power output, and convert the current signal into a voltage signal through a resistor voltage divider. The resistor voltage divider module is connected to the overcurrent signal output module through the current sampling chip and is used to set the overcurrent protection threshold. The overcurrent signal output module is connected to the current sampling module, the resistor voltage divider module, and the overcurrent signal reset module through the current sampling chip, and is used to output a signal to turn off the power switch when an overcurrent condition is detected. The overcurrent signal reset module is connected to the overcurrent signal output module through the current sampling chip and is used to reset the overcurrent protection signal.
2. The overcurrent protection circuit as described in claim 1, characterized in that, The current sampling module includes resistors R21, R22, and R24, and capacitors C54 and C55, wherein... One end of resistor R21 is connected to the power input, and after connecting resistor R22, it is connected to pin 8 of the current sampling chip. The other end is connected to the power output, and after connecting resistor R24, it is connected to pin 7 of the current sampling chip. Capacitor C54 is connected between pins 8 and 7 of the current sampling chip for filtering the sampling signal input; capacitor C55 is connected between pins 1 and 4 of the current sampling chip for filtering the power input.
3. The overcurrent protection circuit as described in claim 1, characterized in that, The resistor voltage divider module includes resistor R23 and resistor R25, wherein, One end of resistor R23 is connected to pin 2 of the current sampling chip, and the other end is connected to pin 3 of the current sampling chip; one end of resistor R25 is connected to pin 3 of the current sampling chip, and the other end is grounded.
4. The overcurrent protection circuit as described in claim 1, characterized in that, The overcurrent signal output module includes a resistor R31, wherein, The current sampling chip's 6th pin is connected to a 3.3V power supply via resistor R31, and the signal is simultaneously output to the / OCL_O network.
5. The overcurrent protection circuit as described in claim 1, characterized in that, The overcurrent signal reset module is connected to pin 5 of the current sampling chip. When it is necessary to reset the overcurrent signal, the overcurrent signal reset module sends a low-level signal to the current sampling chip.