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Hello guys, I am driving DC motor 12volts 6Amp via mosfets with Heat sink & cooling fan, the problem is that when I decrease the duty cycle below 20% the mosfets become very very hot (some times burns out), It works fine above 50% duty cycle runs motor under normal temperature. How I can protect mosfets from burning??
Hello to all. I am trying to design a VCO in 90nm TSMC. The problem is that the current mirror i am designing has large mismatch between the Iref and the Iout. I am using rf nmos transistors to design it. The model i have available has maximum length in nmos 240nm. Can i use a dc mosfet to design the curent mirror? Thnx
Both lower side mosfets have a pull down resistor connected to the gate, these resistors switch the lower side mosfets on by default and it doesn't seem a good idea
Hi! I am trying to build a high power speed controller for a DC motor. I want to control the motor only to one direction. I decide to use a single mosfet with a mosfet driver as the following schematic
i use this mosfet the schematic is the gate of the PMOS is connected to Vcc and the gate of the NMOS is connected to GND, the problem that i found there is a current that pass th
A. Situation -------------------------------------------------------------------------- 1. I wanna a pulsed current(1mA, 0mA) to a load resistor(R0). 2. M1, M3 are current mirror pairs. 3. M1 is generating a Vgs1(for 1mA) and M3 is copying a Vgs1 so that M3 can flow current of 1mA. 4. M2 is a switch for shorting and opening between Vg1
Hi, Sorry if the questions sound stupid!! I'm just confused and need help! I'm working on a power inverter project, im using two Power mosfets 'FQP30N06', at 100KHz PWM, do I need a gate driver to control the FETs or connecting the gate directly to the PWM pin output from STM32F4 is enough? I tried connecting them directly from the pinout, t
I have not MTP3055.Can I use IRFZ44N in this
PROJECT DESCRIPTION: There are 6 different channels or filters ( based on frequency ) to route the RF signal. Each channel or filter is made up of a circuit containing a set of PIN diodes. To switch on to the particular channel or filter (let say channel-1)PIN diodes of that channel(ch-1)needs to be switch ON (by providing +5V) & simu
i use the folling charger for charging 48v battery but have problem mosfet blast after some time plz suggest
Sinisa how do you get 4K/W, can you show more details, .....will mosfet's share current evenly? what about temerature effects? 4K/W was approximate calculation for example given, based on static ON condition. Rth(h-a)= ΔT/Pd -Rth(j-c) -Rth(c-h), ΔT=Tjmax-Tamax With insufficient data given on how MOSF
Hi all, I am writting my diploma about TCADs and have a problem in a practical part. I must simulate mosfet. And I have a process list of the real one. I use Sentaurus Process. And I don't know how to realize phosphorus diffusion to silicon(to generate source and drain regions) with 5e19 concentration, 900C temperature and 10 min. Silvaco
I replaced mosfet irfp460 with irfbc30 having 600v 3.6A rating, 200nf with 1uf capacitor and diodes with mur160.I added TLP optos between MCU and IR2111. I gave 24V dc to the power dc rail and connected 24V lamps in star .GND signal of logic circuit was connected to negative dc rail.The lamps glows well. So I opted to give 325DC voltage to the
I think you should upgrade your mosfet to higher curent ratings and observe
Hi All I am using LTC3810 in one of my application. As given in the datasheet ,I used Si7852 / Si7174 mosfets as TOP and BOTTOM mosfets. My Input is 24V ( range is 21v to 62v)and Out put is 12v @ 3A and switching frequency is 250Khz. This gives us duty cycle of 50% at Swithcing node. I got very clean switching node waveform. My application
Hi, I am working on the electrical system for a small race car, and have a problem. In my dash, I have a Polaris/Arcticat snowmobile/atv kill switch (Polaris part no 4012269). The kill switch is to turn on/off the master relay (tyco 1904000-1 with internal voltage suppression resistor) in the fusebox which in turn feeds the switched +12 to the fuse
HI. i have constructed this linear amplifier 500w rms (2kw pep) (50ohm) with 12 mosfet irfp360, for 160m band. When i gave 3watts of driving r.f power, it gave to output only 190w at 106VDC (6A current). Two radio amateurs who have construct this linear claim tha it gives 500w r.f power at 110vdc. But
700V mosfet 0f TSMC. When I use 700V mosfet model in spectre. Error of spectre simulation is that 'hisim_hv' is an undefined primitive device. When I exchange "hisim_hv" with "hisim" in process file of TSMC, warning of spectre simulation is that 'xqy' is not available in HISIM1.0.1, and error occurs in netlist. When I exchange "hisim_h
Hello there, Currently I doing DC simulation on P-channel Power mosfet. at normal temperature(25 degree c) the leakage current is very small but when simulated at high temperature(90 degree C). problem pop up. Even when the mosfet is OFF. thre still current leak through to ground (the transistor output is connected to re resistor before (...)
Will this half bridge circuit have a problem? If High side mosfet kept on with constant voltage at its gate, but having very low current spikes through the gate, e.g approx 0 amps low side mosfet driven by pulses signal, e.g pwm, and having around 1A spikes through the gate.
Respected sir, i m implementing a N channel mosfet H bridge circuit but i faced a problem for heating of mosfet 1, which connected with the 24 volt supplies. give me proper solution with schematic diagram
hi everybody, iam going to build a buck-boost converter and i use the tlp250 to fire the mosfet and i have a problem that the o/p voltage is much lower than the correct value and i think that i have a problem with grounds (ground of the cct of the converter,the ground of the microcontroller and the ground of the tlp250) images.elektr
Hello sir I am facing a little problem in my DC motor speed control project. when i connect the oscilloscope probe with the Gate of the mosfet its show the pulses but it looks like the pulses have some high voltage spikes as shown in the picture. How to suppress these spikes ??? 64107 64108
Hi, I`m new here and my english is not good but I`ll try to describe all details related to my problem at best possible way and I hope that somebody will help me in this problem... I have old APC BACK-UPS PRO 420, and for some reason on this ups stop to work, after checking what is problem I see that main transformer is burned and one (...)
As one constraint in my assignment I have to use P-channel mosfet, as the switching device in my SMPS. Switching frequency is 100kHz. As illustrated in the image, during switching on, there is a ripple (which cripples everything). what can i do to overcome this? Quick replies are very very valuable as I'm in a hurry. 68655[/AT
hi.. i am using mosfet driver ic EL7104 for the pulsed laser SPL LL85. the circuit is giving proper response on the breadboard and the laser is emitting pulses. but now once i made the PCB of the same circuit. the driver ic is not giving any response. i have used the oscilloscope to check the response at various point. the pulse generator
The mosfet acts as a switch. So, when it is on, you can think of it being a short between drain and source. You will get 120V across the load and 0V across the mosfet (ideally). That's why you don't measure 120V at the drain. Instead, when the mosfet is off, the voltage reading at drain with respect to source, will be 120V, since drain is (...)
I am working on IPD90R1K2C3 mosfet in the DC-DC converters. The mosfet withstand upto with 900V and 150 degrees. But, I am supplying 40V to the input of the circuit and the mosfet getting too much hot which nearly equal to the 150 degrees and above, so that the mosfet's are broken. So, please can you give me the suggestions (...)
hello everyone, I am using ir2110 for driving two mosfet in synchronous mode for DC DC converter, I have irf540 (mosfets) and for driving them i am using ir2110, just tell me that for driving two mosfet in synchronous mode, do i need to give driving signal to both the inputs of ir2110 and do i need to add delay between the switching (...)
The problem is in the mosfet driving. Remove R (short it) or reduce it drastically. Reduce Rb and Rgate. What is the frequency are you using for PWM?
I have a problem with my amplifier input to gate of mosfet is 2Mhz from microcontroller and bias voltage is 30v.when I measure voltage at the terminal of the dc blockin capacitor as i have given in the following picture it shows voltage low close to zero and the frequency about 300 khz.what is the problem ?Because according to the princ
If you check my profile, you will discover that about a month ago I had the same problem. I have the following to tell you: The SG3524 Ic has insufficient dead time to switch the mosfets ON and OFF very well. Consider adding a totem pole arrangement to the output of the IC to fully drive the mosfet. Try using a driver IC like IRF2110 or (...)
Hi everyone. I have built this AC-DC converter, but can't get it working properly. I tested it in simulator and it worked just fine, but on a breadboard (or on PCB) I have had problems. The biggest problem is that the pulse at mosfet's (Q12) gate gets rounded, which heats up the mosfet. Or at least I think that's the main (...)
i am having problem in creating the x and y mesh in atlas for 40 nm mosfet any one can help?
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
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 ? +++
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.
Lets leave apart the the solenoid, motor etc. etc. The problem is if the mosfet is overloaded, only the mosfet should blow, not the driver! Destruction of the driver insists something else... 1. I don't see any series gate resistor to limit the inrush sink/source current from the driver. 1R2110 can handle only 2A current. First and (...)
Hi Finally, the mosfet warming problem was solved. I think this problem was caused by the L6599 and they resolve it by producing the newer generation of resonant controller(L6699). I set the maximum frequency to 200khz and F-start=190khz and F-min=60khz . CF=330pf( due to table6 of L6699 datasheet ) Resonance capacitor=110nF Ls(series (...)
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
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?
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
Dear friend, Each mosfet model has its merits and drawbaks, like accuracy or simulation time, thus converting them maybe loss the accuracy. some programs like @dv@nced D esign Sys. can open all spice format like HSpice or PSpice without any problem like mosfet modeling incompatibility,also this new softs. have a large number of known and (...)
in fact,you problem is not so easy.but if you want low power dispension,maybe mosfet is the only can use four 20V 0.005 oum mosfet parallel,get a very low instance, only about 1W dispension,and four SO8 chip mosfet can work well with about 30 degree temprature warry about others,if you find a error in one power (...)
hi,can anyone can tell me about how to reduce the rf noise of SMPS? and a strange problem,a build a smps of about 50w ,24v2a.when it works,sometimes is good,but sometimes it will sent out 100Hz sound noise,i find when this hanpens,the voltage of mosfet drain is not the same as it works well.but sometimes it will be ok after a few seconds,and maybe
sorry .. how large leakage current about your powerMos ?? as I know power mosfet Ids =6A Cgs=1000p leakage = 0.1ua (Vds=0 Vgs =20v) or SI2031 have large leakage current ..
I have a mosfet that controls a dc motor. Without snubber, mosfet gets hotter and hotter. With a diode snubber, this time diode gets hot. I used a slow diode. I'll also try a fast diode but i wonder that does snubber helps to reduce the dissipated power or does it take it from mosfet onto itself? I mean, must i use a huge diode or can i (...)
I have a 24V dc motor. I'm driving it using a mosfet by using pwm method which is at 20KHz. I remember that i was able to apply max voltage(I mean i suddenly apply any duty cycle e.g. %50) and the motor was responding it before. I don't know what happened but know the motor doesn't start normally. It starts if i connnect a diode across the motor t
It looks like you are making a constant current source or current limiter. You will need to use a P type mosfet for the series pass transistor and put the source to the input and the drain to the output. This is a good situation where SPICE type simulators are very good because you can examine the simulated currents. PSpice has a free studen
Speaking for BSS89 small signal nmos, If I do not use gate resistor then the transistor is more likely to be damaged. I throw away tens of these mosfets to find if the problem realy comes from unused gate resistors...and now I am sure....