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440 Threads found on edaboard.com: Mosfet Problem
I'm having some problems with my mosfet (IRF840 Vds 500V). Im trying to get a 230V motor working with a 3.3V signal from a raspberry pi. I've included the schematic. The GPIO.OUT is the output of the raspberry pi. When the 100K resistor is in place the mosfet seems to be turned 'off'. When I remove the 100K resistor the (...)
Hi, please give us YOUR schematic. And please post a photo form your circuit. *** I know you use the same parts as in the LM datasheet. But I don´t like the mosfet selection. It is rated with ABSOLUTE MAXIMUM of 60V. But the application say input voltage up to 60V. So any little spike at the mosfet will run it out of specification. With a go
I am trying to drive H-bridge using MC33883, but at more than 2A my upper side mosfet get heating too much. 126640
I have a square wave (output from a mosfet bridge) that swings from -100V to 0V referred to AGND (see picture) at ~60kHz; in some situation the signal has very narrow positive peaks (width of few ns). I need to detect those peaks, since if they go too positive they can destroy mosfets. A threshold of 15V would be OK. I tried the circuit in figure:
Hi Everyone, am designing a class A power amplifier using a mosfet at high frequencies 100 MHz - 300 MHz and I just want to pass 100 mA current in the load. But I am facing some problems regarding: 1. The mosfet choice, thermal management is a problem; 2. I am using the LM324 for adjusting the drive signal; but it has a (...)
Why do you think it will work without the mosfet? Does your car drive fast without its engine?
Thanks for your help I changed my circuit. However, this error yet exist. 125564 How I can change time step and insert bootstrap diode? - - - Updated - - - Excuse me I changed my circuit to this and error was solved 125565 But when the PWM is '1' (=when LIN=
Hi, I want to build a buck converter. I use the IR2113 gate driver but the voltage of VB and VS Ho, HL is zero. what is my problem. I think my connection it's not correct. 125502 thank you so much
Nobody makes an NDT2955L, but they make an NDT2955NL. It is spec'd to work well when its gate-source voltage is as low as 4.5V but some of them barely conduct (250uA) when at the threshold voltage of 4V. Buy a few thousand of those mosfets and test them all. You might find one or two that work at a little less than 4V.
Hi, The Background: Trying to understand how a BLDC motor controller works. The system would comprise a microcontroller generating the PWM signals (6 of them, one for each mosfet), which would be fed to three IR2110 mosfet drivers using a synchronous rectification (active freewheeling) drive schema. (the microcontrolles handles the deadtime prob
COSEL make power supply model LDC30F1 not working due to missing of gate pulse of 5v for operating pulse for power mosfet K2045. I also replaced K2045 & optocoupler NEC2561 but problem still prevailing. Kindly do me a favour to rein in the problem. Moreover provide the schematic of the same.
Hello experts, I am working with Solar Charge controller. For charging battery with solar there is a diode (.3v junction difference) between Solar positive and Battery positive. Diode protects the flow of current from battery to solar. That's good but during day time it makes up a good power loss (.3 volt X Current) so i need a heavy heat sink.
I've done some bipolar power mosfet drivers (back in the '80s and '90s, before HV CMOS / BCDMOS was suitably robust for my end markets). Took a lot of care to stay out of saturation and meet the ~50nS prop delays, loaded. Those could run out past 1MHz but really the frequency is less the problem, than the short-pulse limit - where do you s
Hey,can any body provide to me the advises on how the IR2110 can be used for driving the six mosfet making up a full bridge,for controlling an asynchronous three phase machine,my PIC is generating the highly active PWM pulses on its three CCPX Modules. I have a problem on how I can connect the input pin LOW and HIGH of the Driver from the PIC,I
Hello, I start to work on modeling of SiC based converters and need to have reliable model of SiC mosfet in Pspice. I found a CREE model of SiC mosfets C2M0080120D on the following website: However, after impor
HI all, I am making a small project in which i am using a 3.7v li-ion 2600mah Battery, 20x4 LCD, step up converter, mosfet, 89S52 and a keypad. my concept is to just print a command on LCD. so for that i wrote a command like... printscreen("HELLO WORLD, HOW ARE YOU"); i prints absolutely fine. but the problem is it prints giving s
Dear All, I download and add the pspice model of the ir2113 and some other in the ir21xx family. In the model, there is a COMP subcircuit. What is this? When I simulate my circuit I encounter with the bellowing error: "There are not data values in section number 1" Can any body help with? Regards, Ras
Short-circuiting the mosfet would not help much to prevent simulation errors, particularly if the mosfet model is not likely to trustworthy represent the parameters of the real-world device. You are also not providing any gate resistence as would be expected at an authentic circuit. I would recomend you start by using some working curcuit/topolo
AS RdsON goes lower in mosfetS CIss and Coss increases. If your series cap is small compared to this, then the impedance ratio at this frequency will determine the response time THus if resonant , smaller L bigger C in the buck boost resonant circuit. or change the mosfet with better FOM for RdsOn*Ciss FOM is a designers figure of merit, you cal
I don't know the AWR AO tool, sorry. Does your CMOS Ring Oscillator use the same mosfet models (BSIM3V322(P)) as the "Push Push" Oscillator example?
Hi everyone, Currently, I am repairing a Power Supply 24V 20A of Siement, I have a problem with 2 power BJT and a mosfet. The BJT is BU508 and mosfet is BUK543-50B. The mosfet is switching on for the BJTs, and the BJTs is switching on for tranformer. They are broken, I have replaced the mosfet is IRFZ44 (I (...)
Maybe this? FDG332PZ P-Channel PowerTrench? mosfet -20V, -2.6A, 97mOhm
Dear all, Can anyone explain in details about soi structure.why it is good/bad.what are the issues with structure.the i-v model for this type of structure. Thanks.
Hi, what topology are u using, single conversion, double conversion, what voltage are you inverting from. you have to say. Many times what you give is what you have. even if u parallel a 100 mosfets if there is no where to source it you cant sink it. Thats one of the rule of thumb in Electronics. Enumerate further share your idea very well then pe
Hi, everyone, here is the problem, i used spice in of IC615 to convert the spice netlist to schematic, it says successful, but the width of mosfet is not correct, it is all 2u,which is obvious not right, but the total width of mosfet is exactly property in the netlist. I set the reference library and map file, so does anyone know this (...)
Hiii friends, .... if not how to make it working condition without changing circuit? what is the type no of the mosfet you have assembled already ?
Do you expect a mosfet being turned on with 1V gate voltage? Show the gate waveform.
Hi all, I simulate a clock oscillator with hspice using a priopretary mosfet model (.option scale=0.12u) . The weird thing is that in Hspice X-2005.09 under Windows 7 there is no problem at all. However, when I try to simulate the exactly same netlist in Hspice A-2008.03-SP1 under Linux I get the message: **error** reference 0:nfe
The TC4421A/TC4422A are improved versions of the earlier TC4421/TC4422 family of single-output mosfet drivers. result is better dead time and separate hi/lo outputs to control dead time in next stage. The problem is not that RdsOn is 2 Ohms max but that the
The 3.3V mosfet isn't appropriate for its 5V input voltage. Seems there is a voltage breakdown of the bulk-drain junction. You will need a 5V mosfet in this application. Or perhaps you can limit the bulk-drain voltage to max. 3.3V by design provisions.
Hi everyone, 115815115816 In the first picture, the circuit does not work when it is connected to the sbreak switch. In the second picture, the circuit works when it is connected to the gate driver (E) and the mosfet (IRF150), but the result goes wrong. I connected the upper dual flyback cir
Hi all, I am testing my designed circuit all things is alright, except the drivers. the driver circuit is shown in below picture. it is ok when mosfet is not connected to the source (second picture). but when I connect drain of the mosfet to the positive rail of the source (power section), the output waveform of the driver turn like the third pic
You didn't report any results (e.g. calculated versus measured losses), so I can just guess that you understimated the losses caused by charging the mosfet output capacitances. I presume you have varied deadtime to verify that it's not a cross-conduction problem.
Hi, I am aware that in order not to burn a n-ch while driving inductive load, a flyback diode is being used. I am current using a half bridge to drive a BLDC motor. The half bridge mosfet chip kept burning out. The n-ch was ok. It was always the p-ch that kept burning. The p-ch becomes a permanent short circuit. Flyback diode had been plac
For the mosfet Q3, from datasheet it looks like it cannot function at switching frequencies of more than 5.55MHz with typical values. Check the Switching Characteristics in its datasheet.
What's the duty cycle of your rectangular 500Hz signal? Seems like the bootstrap capacitor doesn't have enough time (or enough current) to charge. What's the voltage across the bootstrap capacitor? It has a high ripple, I suppose. You should try a faster bootstrap diode, a decoupling capacitor across Vcc and a smaller gate series resistor. [COLO
I'm trying to avoid an isolate power supply for the high-side switches (mosfet full bridge) so I came up to the only remaining options: bootstrap technique or a charge pump. The problem is that I need a powerful power supply as I'm going to use high current mosfet drivers (TC4452 - 12Amps). I have the possibility to use a bootstrap (...)
Hello dear edaboard members ; I'm really tired of getting the same error from proteus :( I have 48 to 12 V dc-dc converter pre-design(not completed to apply in real life) with UC2525 PWM regulator chip. My problem is when i am trying to drive to mosfet gates(IRFZ44N) PWM-A(pin-11) is nearly correct but PWM-B(pin-14) is about to gnd.(some 1V peak
My last question is how to calculate the input power with cadence i tried (Iavg*V) but it is too large Iavg*V is of course right. The question is how much power is consumed by shoot-trough, simulataneous conduction of both mosfets. You may want to generate separate gate signals with deadtime.
It's not clear what the gate resistor is, it looks like 1.1K to me, but I'm not sure; in fact, I can't really read anything on that schematic. That 1.1K would be inexplicably large, but shouldn't cause a static problem. It's also not clear what "1 Volt at low state" means. You mean when the mosfet is on? (Low). Or when the Gate voltage is low
HEllo, I want to plot the thermal impedance vs pulse width tp at different duty-cylce for a mosfet in pspice. I've the RC thermal network with me. I could plot for single shot but not able to plot at different duty-cycle. Thanks.
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
THe unspecified problem I believe is the OPs largest voltage Vdd is Vref or not much more and that 1 to 2V causes problems for precise tolerance of Vgs threshold, e.g. tolerance 1.5V +/-0.5V. The next is availability. THere are sub 1V Vgs switches, but what tolerance? What is required is an ultralow threshold switch with a low threshold. In t
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.
OK, do not put a full bridge to replace D6,7. You do need a snubber across the mosfet say 150pF 1kV, and 47 ohm for starters (2W), also a string of zeners across the mosfet, 750 volts worth, say 5 x 150V 1.3W in series, and snubbers across D6,7 say, 1nF 500V, and 10 ohm for starters (2W). The 1N5399 is too slow, you need 2 x 600V U-fast i