In order to make the sweeping robot really play a role, intelligent control and efficient driving are very important. In the design and application of the sweeping robot (EV) vacuum cleaner, the selection of the right MOSFET is the key. As one of the core components of the sweeping robot vacuum cleaner, the performance of MOSFET directly affects the charging efficiency, system stability and the long life of the equipment. Our MOSFET product, VBE2610N- -VB-semi, is widely used in this scheme because of its low on resistance and high threshold voltage, high efficiency and high reliability. It provides stable and reliable power support for these components, ensures the efficient operation of the robot in a variety of complex environments, and improves the cleaning effect and intelligencelevel.
We sincerely invite you to attend the upcoming Munich Electronics Fair, scheduled for October 14 to 16, 2024, at the Shenzhen International Convention and Exhibition Center (Bao'an New Hall)! Shenzhen Weibi Semiconductor warmly welcomes you to our booth 1J21, where we will explore cutting-edge semiconductor technologies and applications together.
This exhibition will feature a range of popular technologies and application areas, including the Internet of Things, new energy vehicles, smart homes, consumer electronics, wearable devices, industrial automation, 5G, green energy, integrated circuits, as well as power semiconductors and third-generation semiconductors. These frontier technologies will provide limitless possibilities for future industrial development. Weibi Semiconductor's products are widely utilized in control boards, battery management systems, LED drivers, smart homes, new energy, and motor drives. We work closely with partners in the power management sector, such as Maoshuo and Kegu, to drive technological innovation and market expansion. Additionally, we collaborate with industry leaders like Foxconn, Xiaomi, and Huawei to enhance smart solutions in the IoT sector. Our partnerships with giants like Midea, TCL, and Ecovacs Robotics further improve the performance of small appliances and motor drive products.
With high-quality products and exceptional service, Weibi has earned the trust of numerous industry leaders and established solid partnerships with many well-known companies. We look forward to collaborating with more outstanding enterprises to promote technological advancement and market development. During the exhibition, we will showcase the latest product technologies and industry solutions, sharing successful case studies from various application fields. Whether you want to learn more about our products or explore cooperation opportunities, our team looks forward to engaging in in-depth discussions with you.
Booth reservations are in full swing! Book now to join us at this industry event and embark on a new chapter in the future, exploring new prospects in the semiconductor field together!
First, microcontroller I/O ports have limited load capacity, typically allowing currents around 10-20 mA. Therefore, they are generally not used to drive loads directly.
Let’s briefly compare the differences in driving BJTs and MOSFETs.
Bipolar Junction Transistor (BJT):
BJTs are current-controlled devices. As long as the base-emitter voltage (Ube) exceeds the threshold voltage, typically 0.7V, the transistor will turn on. For BJTs, 3.3V is certainly greater than Ube, and the base current (Ib) can be calculated as \( Ib = \frac{(VO — 0.7V)}{R2} \). By connecting an appropriate resistor in series with the base, the BJT can operate in saturation. Microcontrollers usually aim for low power consumption, so the supply voltage is typically low, around 3.3V.
MOSFET: MOSFETs are voltage-controlled devices. The gate-source voltage (Vgs) must exceed the threshold voltage to turn on, generally around 3–5V, with saturation drive voltage at 6–8V, which is higher than the 3.3V from the I/O port. If driven with 3.3V, the MOSFET may not turn on fully or could operate in a partially conducting state. In this state, the MOSFET has high internal resistance, which limits its ability to handle high current loads, leading to increased power dissipation and potential damage.
Therefore, it is usually preferable to control a BJT with the microcontroller, which in turn drives the MOSFET. Why use a BJT to drive a MOSFET? This is because BJTs have lower load capacity compared to MOSFETs, making them suitable for control applications. Can MOSFETs be driven directly? While it is possible for some low-power MOSFETs, it is generally not advisable for larger loads.
We understand the switching process of the MOS tube. When an NMOS is turned on, the gate is charged. When the Cgs charge is full, the gate will turn on the threshold. When the NMOS is turned off, the GS charge needs to be discharged. When the charge is discharged, the gate will turn off the threshold. This explains the fast switch and deceleration switch we talked about earlier.
So what is its fundamental mechanism? In essence, it is related to the gate resistance of the MOS tube. Because the gate resistance directly controls the size of the gate current, the switching speed varies with the gate resistance value. And choosing the right one is very important. Different gate resistors can be used for different switching speed requirements of MOSFET.
When the MOS tube is turned on, the gate resistors: R1 and R2 are connected in parallel, and R2 is closed when it is turned off, so that it can be turned on faster and turned off slower; or like this circuit, the MOS tube passes through the gate resistor R1 when it is turned on, and R1 and R2 are connected in parallel when it is turned off, so that it can be turned on slower and turned off faster.
The turning on and off of MOS is a dynamic process. The control end and the gate level are the same during continuous off or on, but the control end and the gate level are different at the moment of turning on and off. The gate level changes slower than the control end level, so the different levels will cause the gate current to flow into or out of the gate.
Increasing the gate resistance value will slow down the switching speed of the MOSFET and increase its switching loss. Reducing the gate resistance value will increase the switching speed of the MOSFET.
This has actually been mentioned in the previous section about the selection of the size of the resistor. It is not recommended to use K-level resistors when controlling the switching speed. Common resistance values are 3.3Ω/10Ω/33Ω, etc. Some relatively large discharge currents can be achieved by selecting low output impedance MOSFETs or voltage devices, such as using accelerating diodes.
Why is the voltage higher in a BMS system than in a system?
Before the MOS tube is shut down, a large current flows through the MOS tube to power the load, which is almost the same voltage across the load as the battery at each end.
Because the current does not change much, the parasitic inductors L1 and L2 are like wires.
When the MOS tube is turned off, the current of the inductor cannot change suddenly, so a loop is required to maintain the current, and the inductor becomes a small power supply.
The energy previously stored in the inductor requires the release of an electric current, but the current creates a voltage on the inductor.
In other words, this circuit (including the battery) has three power supplies connected in series and applied to the MOS tube.
Therefore, this total voltage must be higher than the battery voltage.
How much taller is it?
The L2 inductance is generally related to the positive and negative poles of the battery and the leads of the BMS system, and the parameters are generally relatively small; L1 inductors are different. In the case of over-current protection and short-circuit protection, the current is relatively large when the current is turned off, and the voltage drop will be large enough to penetrate the MOS transistor.
How to solve it?
You can make the MOS tube close slower, so that the di/dt will be much smaller and the voltage on L1 will be lower.
What is the function of the pull-down resistor on the of a MOSFET?
The pull-down resistor between the gate (G) and source (S) of a MOSFET serves several functions: 1.Preventing False Turn-On: The Miller capacitance, a parasitic capacitor between the gate (G) and drain (D), can cause the MOSFET’s drain-source voltage (Vds) to change from nearly 0 (saturation voltage drop) to the bus voltage when the MOSFET is turned off. This rate of voltage change is "dv/dt." Since a capacitor responds to voltage changes by generating a current, the voltage change across the capacitor generates a current "i."
The gate-source (G-S) junction has an insulating layer, usually silicon dioxide (SiO2), making G-S a high-impedance path (tens to hundreds of megaohms). If there is a driving abnormality, the current through the Miller capacitance can charge the G-S junction. A small current through a high impedance can correspond to a high voltage, potentially charging the gate voltage above the threshold voltage "Vgs(th)," causing the MOSFET to turn on again, which is a dangerous situation.
2.Providing a Discharge Path: In a flyback power supply topology, the Miller capacitance current is discharged through a low-resistance path inside the driver chip, preventing the gate from being charged high enough to cause a false turn-on.
Here, we understand that there is already a discharge pull-down resistor inside the driver chip. However, if the gate resistor (Rg) is open-circuited or not connected for any reason, the external pull-down resistor (R8) can provide a discharge path for the Miller capacitance, keeping the G-S junction of the MOSFET at low impedance for a stable and safe state. This is a critical function of the pull-down resistor.
3.Pre-Protection Resistor: Another function of the pull-down resistor is as a pre-protection resistor. The G-S junction of a MOSFET is high-impedance, which is why it is sensitive to ESD. High voltage applied to the gate is not easily discharged and, over time, can damage the silicon dioxide layer between the G-S junction, leading to device failure.
Therefore, the pull-down resistor balances power consumption and effective discharge. Typically, for low to medium power supplies (0-500W), a resistor value of around 10K-20K is chosen, while for high-power supplies, 4.7K-10K is selected.
That concludes this content! Thank you for your support!
How to distinguish whether the tube in your hand is N tube or P tube?
First, let's take the enhancement MOS tube as an example. This is the circuit symbol of the two:
You can see that the directions of the two arrows are inconsistent.
This arrow is its substrate, because the internal substrate and source of the MOS tube are connected together.
The biggest difference between the NMOS and PMOS circuit symbols lies in its substrate. The arrow of NMOS points to the gate, while the arrow of PMOS points back to the gate.
The direction of this arrow is related to the direction of the PN junction between the internal substrate and the channel inversion layer of the MOS tube.
Secondly, the body diodes of NMOS and PMOS are opposite.
The anode (i.e. positive pole) of the body diode of the NMOS tube is connected to the source, the anode of the body diode of the PMOS is connected to the drain, and the negative pole of the body diode is connected to the source.
So, how to distinguish the three pins of the MOS tube?
You can use a multimeter to test it. Here is a brief explanation.
Take a MOS tube packaged as TO220, which usually has a heat sink, and the heat sink will be connected to the drain. Use a multimeter to test which pin can be connected to the heat sink, which corresponds to the drain.
Because of the connection of the diode, there are diode characteristics between the drain and the source.
Therefore, when using a multimeter to test the drain and which pin can be connected in both forward and reverse directions, it is the source.
The rest is the gate.
In summary, there are two points:
1. The positive pole of the NMOS diode is generally connected to the source
MOS has a body diode connected in parallel between the D and S poles, so why is this diode connected in parallel?
This starts with the process and structure of MOS. The diode is composed of a pair of PN junctions. The P-type region corresponds to the positive pole of the diode, the N-type region corresponds to the negative pole of the diode, and the PN junction is in the middle. SiO2 in the MOS tube itself is not conductive, so the driving pole G basically does not carry current.
In addition to the three poles D, G, and S, there is also an intermediate pole, which is connected to the S pole, so in the circuit symbol of MOS, the arrow pointing to the channel N channel inside the MOS is connected to the S pole.
In addition, the drain of the N-type region is connected to the middle P-type region and then to the source, which just forms a diode structure, so a diode is connected in parallel in the MOS symbol.
What is the use of this body diode?
In some scenarios, such as battery protection, after the lithium battery is over-discharged, the protection function will be turned on: turn off the discharge MOS. When the charger is plugged in, the MOS body diode is used to make the circuit conductive and the system work normally. However, in some scenarios, the existence of this diode is undesirable because it may cause leakage between the S pole and the D pole.
When the gate voltage is greater than the turn-on threshold, the MOSFET is turned on; when the gate voltage is lower than the turn-on threshold, the MOSFET is turned off.
In actual applications, due to the influence of other factors such as device and peripheral circuit parasitic parameters, the originally turned-off power device may be mistakenly turned on.
Today, let's talk about the mistaken turn-on of MOSFET in the drive circuit and its countermeasures.
Let's talk about two cases of mistaken turn-on: mistaken turn-on caused by Miller effect and mistaken turn-on caused by parasitic inductance.
False turn-on caused by Miller effect
When the MOSFET is turned off and then turned on, the Vds voltage (the maximum voltage that can be applied between the drain and the source) rises rapidly to produce a high dv/dt (the rate of change of the drain-source voltage during the switching transient), thereby generating a displacement current (igd) in the capacitor Cgd (Miller capacitor).
This displacement current will generate a voltage spike after flowing through . If this voltage spike exceeds the turn-on threshold of the MOSFET, the MOSFET will be turned on, causing the circuit to be turned on or even damaged.
Another type of false turn-on is caused by parasitic inductance on the line. As shown in the figure below, Ls is the parasitic inductance on the source of the MOSFET.
When the MOSFET is turned off quickly, the current decreases rapidly to produce a high di/dt, and then a negative voltage (VLS) is generated across the two ends of the parasitic inductance. If this VLS voltage exceeds the gate threshold of the MOSFET, the MOSFET will be turned on by mistake.
So, what methods do we have to deal with the phenomenon of MOSFET being turned on by mistake?
1. Adjust the gate drive resistor and capacitor
The turn-on/off speed of the MOSFET can be adjusted by adjusting the size of the gate drive resistor and capacitor: increase the gate drive resistor and capacitor to slow down the turn-on/off speed of the MOSFET, reduce dv/dt (di/dt) and thus reduce the gate voltage spike.
2. Add a transistor
A transistor can be placed near the gate of the power tube to prevent false opening during the shutdown period, effectively suppressing the false gate opening caused by the Miller effect.
3. Use an anti-parallel diode
The current in the inductor can disappear through the diode loop, thereby avoiding the generation of reverse potential.
In the context of the current global energy transition, the utilization rate of renewable energy continues to increase. Clean energy such as solar and wind energy has become an important part of the energy structure. However, there are still challenges to the efficient conversion and storage of these renewable energy sources VBP1254NMOSFETs were introduced by VBsemi because their excellent performance and reliability are key factors in solving these problems.
High-efficiency inverter core
The inverter is an important equipment that converts direct current into alternating current, and is widely used in solar power generation systems and wind power generation systems. The emergence of VBP1254N provides strong support for the efficient energy conversion of inverters. Its drain-to-source voltage (VDS) of 250V and drain-to-source current (ID) capability of 60A enable MOSFETs to handle high-power power conversion.
In addition, VBP1254N uses advanced trench technology to provide low on-resistance (RDS(on)). When VGS=10V, the typical value is only 40mΩ. This feature significantly reduces energy loss, improves the conversion efficiency of the inverter, helps the system maintain low heat accumulation at high power output, and extends the life of the equipment.
A reliable choice for battery management systems
In renewable energy systems, the battery management system (BMS) is critical to the performance of energy storage devices. VBP1254N is a reliable choice for battery management systems due to its stable performance and high threshold voltage (Vth, 3.5V typical). MOSFETs can effectively control the current during charging and discharging to ensure the safe and efficient operation of the battery pack under different working conditions.
Its ±20V gate-to-source voltage (VGS) capability enables VBP1254N to operate reliably under extreme conditions. This is particularly important for fast response and high reliability requirements in energy storage systems, ensuring that the system can quickly adjust the current under various load conditions, avoid overcharging or overdischarging the battery, and prolong the battery life.
Application prospects and advantages
The high performance of this VBP1254N makes its use in renewable energy systems very promising. Whether it's an inverter or a battery management system, this MOSFET performs well. Its excellent performance in high-power energy conversion and energy storage applications perfectly overcomes the relevant technical difficulties and provides a solid guarantee for the efficiency and reliability of the energy system.
Examples of other areas of application for this product
1. Industrial Automation:VBP1254N can be used for motor drives and control systems in industrial automation. Its high current handling capability and low on-resistance make it ideal for high-efficiency motor drives. Whether in factory automation equipment or robot control, the equipment provides reliable power transmission and stable performance.
VBP1254N perform well in power management modules, especially in high-efficiency switching power supplies and DC-DC converters. Its low on-resistance and high threshold voltage guarantee high efficiency and system stability for energy transfer, making it a core component of an efficient power management system.
High-performance devices designed to address high-power energy conversion and energy storageIssue. It not only improves the overall efficiency and stability of the renewable energy system, but also provides strong...Read more
We know that push-pull circuits come in many types, such as class A or class B amplifiers. Class B amplifiers are the ones used in practical applications. They are more efficient than class A, but they are often affected by crossover distortion.
So how does it affect it? How can it be reduced?
When the signal is distorted at 0V, the transistor will provide a voltage of 0.7v at the base-emitter junction before turning on. When the AC input voltage is applied to the push-pull amplifier, it increases from 0 until it reaches 0.7V, and the transistor remains off without any output.
So why does crossover distortion occur when VIN reaches zero? (Class B amplifier)
In fact, transistors Q1 and Q2 cannot be turned on at the same time. If Q1 is turned on, VIN must be greater than Vout, and if Q2 is turned on, Vin must be less than Vout. If VIN is equal to zero, Vout must also be equal to zero.
When VIN increases from zero, the output voltage Vout will also remain at zero. Until V IN is less than 0.7V, the output voltage shows a dead zone, and the same situation will occur when V IN starts to decrease from zero.
How to reduce the crossover distortion of the push-pull transistor circuit?
It can be corrected by using two diodes that are turned on at the transistor position, that is, the class AB amplifier circuit.
It uses the characteristics of both. From 0V to 0.7V, the diode is biased in the on state to make up for the 0.7 V loss of the emitter follower. At this time, the transistor has no signal at the base, which solves the crossover distortion problem.
In addition, it can also be achieved by reducing the resistance value.
This is because the resistor RB1 controls the current of D1. The smaller RB1 is, the greater the current is, that is, the greater the voltage of the diode is, so when there is no input signal, the Vbe will be greater. This increased deviation will further reduce the distortion.
However, the specific application situation is still based on the actual circuit design.
VBGP1201N, a dedicated MOSFET for electric vehicle (EV) charging piles, guarantees your charging efficiency and system stability
In the design and application of electric vehicle (EV) charging piles, choosing the right MOSFET is the key. As one of the core components of the charging pile system, the performance of the MOSFET directly affects the charging efficiency, system stability and long life of the equipment. VBsemi's VBGP1201N power MOSFET has become an ideal choice in the field of electric vehicle charging piles with its excellent technical characteristics and performance advantages. This article will focus on the application of VBGP1201N in electric vehicle charging piles, analyze how it improves charging efficiency, ensures system stability, and the actual application scenarios in charging pile design.
---VBGP1201N core technical parameters
VBGP1201N is an N-channel MOSFET in a TO247 package with a 200V withstand voltage and a ±20V gate-source voltage. Its typical threshold voltage (Vthtyp) is 4V, and the on-resistance (RDS(on)@VGS=10Vtyp) is only 8.5 mΩ.
Voltage Withstand (VDS)
200V voltage withstand: The VBGP1201N is able to operate stably under high voltage conditions, which is critical for electric vehicle charging piles. Charging piles usually need to handle higher voltages when performing power conversion. The high voltage withstand capability of the VBGP1201N ensures that there will be no breakdown under these high voltage environments, thereby ensuring the safety and reliability of the charging process.
Gate-Source Voltage (VGS)
±20V gate-source voltage range: This feature provides great flexibility in circuit design, allowing designers to adjust the switching characteristics of the MOSFET according to actual needs. This design flexibility is very important for circuit optimization and performance adjustment of charging piles, which can better adapt to different operating conditions and circuit configurations.
Typical Threshold Voltage (Vthtyp)
4V typical threshold voltage: The low threshold voltage means that the VBGP1201N can achieve stable switching action at a lower gate drive voltage, thereby improving switching efficiency. This is particularly important under the high efficiency requirements of charging piles, which can reduce power loss and increase charging speed.
On-resistance (RDS(on)@VGS=10Vtyp)
Low on-resistance of 8.5 mΩ: This feature reduces energy loss during power transmission, reduces heat generation, and helps improve charging efficiency. This is particularly prominent in charging piles, because low on-resistance can reduce power loss and improve the energy utilization of the overall system.
Continuous drain current (ID)
High drain current capability of 120A: The VBGP1201N can support high current charging requirements, which makes it excel in high-power charging applications. The high current carrying capacity ensures the stability of the charging pile under fast charging and high load conditions, preventing overheating and performance degradation.
---Advantages of VBGP1201N in electric vehicle charging piles
System stability of electric vehicle charging piles is crucial to ensure safe and reliable charging. VBGP1201N uses advanced SGT (Silicon-Germanium Technology) technology, which makes it excel in handling high power and high temperature environments.
Improve charging efficiency
Charging efficiency is a key indicator in electric vehicle charging piles. The low on-resistance (8.5 mΩ) of VBGP1201N can effectively reduce the power loss caused by on-resistance during charging. The efficiency of the charging pile directly affects the charging time and energy consumption. VBGP1201N can improve charging efficiency by reducing power loss, thereby shortening charging time and reducing energy consumption. This high-efficiency MOSFET is particularly important for fast charging technology and can meet the needs of modern electric vehicles for fast charging....
VBsemi is proud to introduce the new TO220 package VBM115MR03 designed specifically for high-voltage applications. With its excellent performance and reliability, this product has become an ideal alternative to traditional high-voltage products.
Excellent performance:
Ultra-high withstand voltage: The VBM115MR03 design supports voltages up to 1500V to ensure stable operation in harsh high-voltage environments and ensure the safety and reliability of the system.
Very low on-resistance: The low on-resistance of only 6000 milliohms effectively reduces energy consumption and heat dissipation requirements, improves system efficiency, and extends equipment life.
Powerful current-carrying capacity: The maximum current reaches 3A, allowing VBM115MR03 to easily handle the high load requirements in most industrial and consumer electronics applications and ensure stable operation.
With its excellent performance, VBM115MR03 has become the first choice for engineers designing high-voltage circuits. It is widely used in industrial automation, power conversion, medical equipment, electric vehicle charging systems, and other fields, with extraordinary reliability and capability.
Benefits & Highlights:
Wide compatibility: VBM115MR03 has excellent compatibility and can directly replace a variety of high-voltage products, including but not limited to IRFBG30, SiHFBG30, IXTP3N120, etc., providing engineers with greater flexibility and choice.
Stable and reliable: After strict quality control and comprehensive performance testing, it ensures that the VBM115MR03 maintains stable electrical performance and reliability in long-term use, reducing maintenance costs and risks.
Diverse applications: VBM115MR03 are widely used in key fields such as industrial control systems, power converters, medical equipment, and electric vehicle charging systems, providing efficient and reliable solutions for various application scenarios.
With these advantages, VBM115MR03 stands out in high-voltage circuit design and is ideal for engineers to choose a reliable solution.
Applications:
VBM115MR03 are widely used in a number of key areas, including but not limited to the following:
Industrial automation control system: In industrial automation, VBM115MR03 is the core component of motor drive, power management and electrical control system to ensure the reliable operation of equipment in high-voltage environments.
Power conversion and inverter: As a key component of power converters and inverters, VBM115MR03 can efficiently convert and manage electrical energy, and are suitable for solar inverters, grid-connected and off-grid energy systems, ensuring stable and efficient energy conversion.
Medical devices: In medical devices, VBM115MR03 are used for high-voltage power management, precision control circuits, and electrical isolation to ensure the safe operation and precise control of medical devices, including imaging equipment, surgical instruments, and monitoring equipment.
EV Charging Systems: VBM115MR03 EV charging systems provide charging efficiency and circuit safety, support fast charging and long-term use, and meet the stringent requirements of the EV market for efficient energy management and reliability.
In addition to the three poles D, G, and S, there is also an intermediate pole, which is connected to the S pole, so in the circuit symbol of MOS, the arrow pointing to the channel N channel inside the MOS is connected to the S pole.
So how does it affect it? How can it be reduced?
