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398 Threads found on edaboard.com: Mosfet Problem
Using a complementary BJT voltage follower raises respectively reduces low and high level by about 0.7 V which involves no problem with standard mosfets.
hi i'm doing a battery balance project while using your mcu. i have an technical question for using battery. i'm using npn mosfet and for controll the batteries which are series connected. can i send 5v to npn fet for make it logic 1? or do i have to send to higher voltage of batteries(higher than 70v)?
i used lm339 comparator with the attached circuit .i want to drive mosfet but the output in simulation is 2.2 v on the pin1 of the comparator .however it should be Vsat. when i decreased R1 to 10 ohm the output on led increased to 5.1 v .what is the problem . i want to get 11 v from this circuit at least and that will only happened if i put R1 = 0
Hi guys. I have to design a comparator operating at high frequency (500MHz) The topology is based on the smetrical ota with crosscoupled load. From rom what I have been exploring I concluded that for the cross coupled mosfet the value of the W has to be lower than the L, that is, for example, 0.12/0.34. The transistors that I AM using are the 3.3
Hello! I need to charge a 1nF capacitor upto a reference voltage of around 1 to 2 volts. A mosfet doesn't serve the purpose because of the threshold issue. Can an analog switch solve the problem? The capacitor must charge right upto the reference voltage without any drop due to threshold or other issues. Please see the attachment for the conne
greetings, To evaluate a mosfet driver IC, I have implemented shown circuit. The upper switch work well. it means when it switch ON, upper lamp gets ON and the other lamp get OFF. but when down switch is fired, the down lamp does not get OFF, however the upper lamp get ON, even when I provide continuous high gate signal the gate resistor is 12 o
please am building a buck converter but am having problem with driving the mosfet switch at 20khz Show all work for best support. schematic, BOM, layout, DSO traces.
PWM regulator used to drive mosfet has FB pin to which sample of output voltage through attenuator is connected. For last circuit it is done with 1M and 6.19k resistors and at 200V output voltage FB gets 1.23V. FB is input to error amplifier with reference 1.24V. Take a look at LT1172 datasheet it has internal circuit.
Hi everybody Hope you all are fine. I'm working on a forward converter which is giving me a lot of hassle. The required output voltage and current ratings are 16V and 2.5A. The switching frequency is 100 kHz with a duty cycle of 35%. This PWM is generated by a microcontroller and fed to the gate via an IR2110 and a gate drive transformer. [AT
I have two identical diagrams here with the placement of the drain/source diode and RC snuber filter, the only difference. I like presenting my question with a diagram because it makes the question a visual subject. These diagrams are for reference purposes only. When I using a switch module, mosfet/IGBT, because they are a kind of single device
If you leave sufficient dead time in the mosfet drive, e.g. 5% then there is a natural reset of the core flux as long as the applied volt seconds are not too different, and this generally keeps the core flux with in reasonable bounds, the exceptions are pulse loads which are odd multiples of the switching half period long.
Question: Since you refer to P-devices, then your schematic #2 has the correct mosfet icons. However they still have a connection from the gate to the lower terminal. Did you intend this?
hello, i have made an inverter using cd4047 as per the circuit diagram i have uploaded here.. as per the circuit diagram gate pulse are given to the mosfet from pin 10 and pin 11 of the IC . but when i apply 12v to the ic i am getting 12v at pin 10 but not getting any voltage at pin 11 but i am getting 12v from pin 13 so i have connected 100ohm re
A Jfet can be used as a current source when its gate is connected to its source. Because a Jfet has depletion mode and conducts its maximum current when Vgs is zero.. A mosfet cannot be used because it has enhancement mode.
there are better ways to protect against an always ON PWM signal. run PWM digital signal through external logic gates being the most simple. on gate driver side, easiest way is to employ desat protection, even with mosfet switch. no problem.
Hi, read datasheet: is PIC capable of driving 100mA and keep an eye on the voltage. increasing current: * the simplest way is to just add a mosfet or BJT. * or complete halfbridge * or driver IC... it depens on what you need. * min voltage, at max sink current * max voltage at max source current * frequency * what load: completely resistive,
Two possibilities: * Your mosfet icons appear unconventional, because they contain an internal diode which points downward instead of upward. In such a case the mosfets will always conduct. * The gate should be pulled to 0V, in order to turn off the mosfet. However if pins D11-12 go to high impedance, the gate adopts an unknown voltage. It (...)
I have PWM of very low frequency and very low duty cycle. And max voltage comes out are 3.3. But thats not enough to open the mosfet's gate(IRFP250N). Now I want to amplify the voltage. I do not have op-amp right now. But I tried to use LM393P comparator but its seems too slow. So if I put LED direct to PWM output I can see it blinking but if I put
Hi... I do with mosfet switch with IRF9530. But It was not working properly. The prolem my switch on time 100 us for every second. Here i attached schematic and output wave form. 108688 How to solve this . Thanks
Somebody help me? I want to simulate a paper but it does not similar paper I download transistor model (mosfet32n h/k and finfet32n) from the site. Ptm., But I do not know what changes should do it on both: w=100n l=32 vin=0.5 My result with this models: Avgpwr mosfet was better than finfet. but
Hello forum I am trying to switch mosfet. I am using 1 ohm resistor. My aim is heating or cooling resistor. First, ı tried basic common source configuration. I used 1 ohm resistor as a drain resistor. My gate voltage is either 3.3 v or 0 v. With this configuration, mosfet cant enter triode region. So how can ı swi
Hi all, I like to drive some switches that half of them have complementary state to other half ( some thing like a full-bridge inverter). in other word if s1=ON, s'1=Off. the situation is like half-bridge operation; so I decide to use a half-bridge mosfet driver. since charging path of boot-strap capacitor is not secured, I have used two separate
Dear all. Recently I have started designing a radio frequency amplifier based on dual-gate mosfet BF998. I have simulated it in HSPICE simulation software, designed input and output matching networks. Unfortunately, This is a four-parameter problem which is suitable to be solved by optimization technique. I need to optimize three inductors and one
Hi I want to build the high voltage smps with the output voltage at about 30KV and maximum current= 20mA with L6599 For disabling standby mode I connect pin5 to pin4 . For disabling current sense I connect pin6 to GND . VCC(L6599_PIN 12)=15.3 volt , It supplied from one 15volt transformer. I have a problem for driving high side mosfet(IR
Hi All, May I ask for NMOS gate driving method with isolation using IR2110 and IR2117? For IR2110, without low side mosfet, the bootstrap capacitor cannot be charged. How can i solve the problem on driving isolation NMOS with high side driver only? Second, can I use IR2117 directly to achieve my goal? Does the bootstrap capacitor charging
I think you should try a mosfet e.g. 2N7000 with source at 'E' and drain at 'C' of Q2. *are you sure R3 is connected to Ground? Allen
i am using ir 2110 for mosfet driver but i am not getting the high side pwm untill unless i connect the output of ic to mosfet gate ? is it necessary to always connect , cant we check the pwm seperately? why is it so?
You see the mosfet substrate diode in forward bias, due to unsuitable transistor connection.
Dear All I am using mosfet in Dual feed convertor mode for driving Inductor coil for Mechanical Vibration as given in AN of IR2110 . I Modified the connection and Ckt is attached here.The Circuit is driven by the PWM pulses from Arduino UNO with default PWM frequency 455Hz. As I start it Both mosfets and IR2110 get Blast.I remove the Q1 Q2 D2 and
You must quick charge and disharge capacitenca on FETs gate: It is often stated that transistors such as mosfets with isolated gate electrodes can be driven without a power source, which is not correct. In contrast to bipolar transistors, mosfets do not require constant power input, as long a
Hi all, I am building a dc-dc boost converter with a UCC27254 (up to 5A peak current source/sink) to drive the low side mosfet. My input voltage is 20V at minimum, and switching frequency is 100khz. I am using an LM7815 linear regulator directly connected to the input voltage, to generate a fixed 15V to power the mosfet driver. I have attached t
Hi, Pls find the attached motor testing bipolar stepper driver circuit which has A4989 driver with IRLR024NPbf mosfet .. Motor runs smoothly upto 2KHz in full step mode only if step input duty cycle set to below 20% & the current through each coil shows 1.3A. if i increase the duty cycle slightly above 20% ..motor is not rotating p
hello i am trying to make a double gate mosfet 32nm through atlas i have made the code and i am getting basic current equation but i am facing problems in extracting the subthreshold slope can anyone help me please i really need some guidance whatever i have made i have done it with help of examples
Hi! I want to simulate AND operation using mosfet's in Proteus. I have attached a screenshot of the design. But I'm not getting the necessary output. (when A and B is logic 1 Z should be logic 1) What is the mistake? 105092
I have designed a three phase pure sine wave inverter with spwm unipolar scheme. I am using a three phase rectifier to supply 200 Vdc on the dc bus of the inverter. Upon connecting a low pass LC filter i am able to get a 100Vrms pure sine wave across all three phase and the inverter is working fine on 100W load per phase. All the mosfets in this co
Guys, I need some help with my circuit which I have attached circuit is intended to be a very cheap solution of a transmitter-receiver channel - the receiver is comprised of R1 and D1 and the rest components are the transmitter. The problem is with the gate voltag
Delay is CV/I, so if you know all these values and current equation of a mosfet (I), figuring out delay should be easy, right? Since this is an inverter, you want to make sure that the current through the NMOS and PMOS are the same, so essentially, size the PMOS so that you get the same current. There are better approximations given in textbooks, b
From the netlist, there are no connections to M2. So, perhaps the problem is not with the resistor but with the mosfet which does not appear in the netlist. Perhaps check your library and make sure M2 is found and it is correct.
IR2110 getting demaged in full bridge inverter with mosfet and Arduino Hi everyone! I've been in the forum for a while, reading and analysing the posts much more than posting, trying to find threads were the solved problems are similar to mine... In many situations I've found answers to my questions, but this time it didn't happened, so I'm
You need to give 12 V as supply and there has to be a low value resistor between the mosfet gate and the driver transistor in series.
The picture you gave is surely a merit figure for some circuit topologies based on switching inductive elements. I could not find above any mention about if you took some action for dump the spike, such as employing a snubber net on mosfet, did you that ? +++
Think about WHY should the power losses be small? If you've got a slow rise time on the mosfet gate, it will dissipate more power. If the mosfet has a high resistance it will dissipate more power. Further, that breadboard is probably not optimum; I'm sure you've got stray capacitance and inductances all over the place.
The general rule of thumb for heating mosfets is either from linear region use, not enough current for switching, or actual conduction (on resistance). 1.) Can you show the circuit? 2.) What is your load that you are driving? 3.) What is the switching frequency? The problem could lie within the speed you are switching at and the 500mA the chip i
i am having problem in creating the x and y mesh in atlas for 40 nm mosfet any one can help?
With a +12.0V supply and a 200mA load some 555 ICs have a maximum output voltage of +9.5V as listed on its datasheet. If you add a high current P-channel mosfet then the output will be close to +12.0V with plenty of Amps. Very correct, while using mosfet you need to wire two transistor (one NPN & one PNP) in a "tote
i am using Ir2112 to drive mosfet, i measured between Ho and Vs which is (Vgs ) and it was 12 volt but the signal wasn't pure square there were a little Curvature in the up side and low side of the pulse . i don't know if this curvature is normal or i can enhance the circuit performance to get it pure square .I sent you the complete circuit for dc
Lots of pictures, but what exactly is the problem? There are so many posts online about how Samsungs were identified by the ticking or clicking relays, and everyone said it was almost always a bulging cap, or failing that it was a mosfet... Well, my Samsung has just joined the fun, but I was surprised to find that upon d
I need to drive mosfet transistor of dc-dc converter using pwm from atmega 8 but the output voltage is 5 v while the mosfet need 10 v to be fully on ? how to process this problem?
Hi guys, I started this thread because my PC's PSU stopped working. When I opened it to check what the problem is, I found two elements damaged, they are a Power mosfet (CEF02N7) and a resistor of 1.2Ohms/1W. Additionaly connected to mosfet gate there are a small IC, on something like a SOT23-6 package, whose code marking is EA546 or EAS46, (...)
can you please be specific?? I mentioned several problems that are often observed in mosfet bridges. You didn't give substantial informations about your design except for showing a (simulation) circuit. No, I can't be presenly more specific.