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463 Threads found on edaboard.com: Mosfet Problem
Hi, i had done simulation on proteus for pure sine wave inverter using pic16f877A and ir2112 it was working fine till the ir2112 output but givig out transient error for the complete inverter output . After reading some articles and blogs i found that it is the problem with proteus. hence i moved towards hardware part, The output from pic is goi
The voltage will drop slightly during the charge pump refresh, as the mosfet turns off and the body diode starts to conduct. That should not be a problem for your equipment. Now, if you want a droop-free output, you may try the Linear LTC4358. It employs the same charge pump principle like the TI unit, but it has an external connection to add a ho
TMR1IE_bit, once cleared in the ISR, is not set again which bars the ISR to act endlessly. #define ON 1 #define OFF 0 sbit Relay at GP1_bit; sbit mosfet at GP2_bit; sbit Charged_Led at GP4_bit; sbit Charging_led at GP5_bit; unsigned char my_flags = 0; unsigned char state_counter = 0, led_blink_counter = 0, led_blink_count = 2, led_blink_d
Hello guys, I am driving 15a lamp via mosfets without Heat sink . How I can protect mosfets from burning?? is necessary pull down resistor? mosfets are very hot.Also ı used logic level ırlz44
SCR might stay latched on, probably a bad choice. An "avalanche rated" mosfet might solve the problem cleanly, depending on the stored energy. Should be app notes / selection info for any such parts. A "catch diode" that returns overshoot energy to the supply could also do the job, less dissipatively than the TVS (TVS will have a Joule energy pe
I'm using an IRS2117 mosfet Driver connected in the circuit below 136321 I'm using a DC power supply to provide the 15V Vcc, and 1uF capacitors for both circuits. The problem is, attaching an input signal from a function generator (square wave, 0-5V, 1kHz), the U8 output is always at 9.8V, and U9 output at 1V. I've
Going to the original question: "Can you tell me are two gate's are interchangeable?" The answer is: Depends by your application. Originally the Dual-Gate mosfet was invented to get a gain-controlled device (input signal on G1, and DC gain-control on G2). Also this device can be used as an RF mixer, applying two RF signals to the gates, and outp
Hi folks, I have four nMOS switches connected in Series with flying cap to boost input voltage to higher level ( circuit schematic attached). I am driving them using Arduino which has capability of 20mA/pin, my switches need only 5mA/switch, So I think I don't need a gate drive. The problem I am facing now how to shift the signals for upper swit
Hi in this schematic the Q1 & Q2 are P&N channel mosfet. but Q1="1RFP450" and Q2="IRFP450" I can't find any datasheet about "1RFP450" Is there any alternative to this two mosfet's
For the benefit of other readers: This problem is as old as audio amplifiers. An active stage, whether a vacuum tube, BJT, JFET, mosfet or an opamp requires some amount of DC voltage "bias" to operate in class "A"; thus allowing an AC waveform to be amplified. Unfortunately this DC would have a detrimental effect on the previous stage, and thus i
Hello I am working on 3 phase motor control by V/F control. my circuit consist microcontroller > IR2110> IRF640. Pwm freqency is 1KHZ Design is non isolated my problem that while mosfet switch on and switch off it create posivite and negative spikes upto +/- 25volts resultant +5v and +15 for microcontroller and ir2110 contant spikes or trans
You should know how you are controlling the stepper motor differently in both modes. We can't. A possible reason for device overheating might be an inappropriate high PWM frequency in combination with a high mosfet gate capacitance.
Hi everybody I have a problem with design a circuits which it has to work at any corner case but it dosen't work. How can I design a mosfet that it will be work at any corner cases? My teacher said that if you want to design a circuits which it work at different corner case you have to look at Vdsat value. I don't know what is relation between
Hi, I am experimenting with a half bridge built arount the IR2110. When trying to determine the turn-on/turn-off times by using an oscilloscope and changing the values of the gate resistor, I found a weird problem: As I reduce the gate resitor value I observe that the turn-on time decreases, as expected. Turn-off time is however aprox. equal
Zero threshold voltage mosfet are called native transistors. They require special masks. You need to check your process. Native transistors have larger lengths typically 2x compared to standard threshold voltage transistors.
Hi. My question is: Why High value of signal OUT drop down when signal for read information is logical "1". The signal OUT drop for about 0.7 V. That is case when is treshold voltage lower (bulk and sours is connected together -mosfet with line of information and write line)-that we need to get higher value of OUT (logical 1). When I us
The schematic in post #3 reveals a problem that couldn't be guessed from the original question. In the picture, switches are going to be mosfet and assume that 4 lithium ion cells are used. As shown, the post #3 circuit requires the gate drivers source reference for all transistors (except the bottom transistor) to swing over the f
Hi, buy mosfets (all things) from reliable suppliers. Then you can rely on the datasheets. Every big manufacturer of mosfets will keep on the specifications given in the datasheets. If you buy parts from unreliable sources, then you never have a guarantee, even if you test them.. Klaus
Variables that also affect switching are rectified voltage and decay RC time constant between pulses and the impedance and voltage of your pulse generator. If it is 50 Ohms, thats a problem. then with only 10uF with a decay time of 4.7ms, with a 8,3ms off time... thats another problem. A 4V threshold mosfet would just barely work with the (...)
R1 connects the gate to the source causing the mosfet to be turned off then the voltage at Node 1 is 0V.
Hi all, i have a circuit that power by 5V/125mA ( usb). i included in my design an P-mosfet as a reverse voltage protection i have used the following pmosfet : PMZB320UPE here is the data sheet : is my pow
The circuits you have seen will have an active circuit driving the gate. That means the driver will make the gate voltage go to (or close to) the source voltage and prevent the mosfet conducting. The problem you observed happens when nothing drives the gate at all and residual charge or interference pick-up keeps enough gate to source voltage prese
Does there any paper related to this topic? high supply voltage, cmos folded-cascade amplifer made by low voltage mosfet and high voltage mosfet both. thanks.
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
If it's wired as you show and the part values are correct (double check the value C99 that it is 470nF and not 470pF) then I see no obvious reason that the upper mosfets should get hot.
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.
Don't understand which problem you are talking about. A mosfet can be always switched on with 6 - 12 V Vgs, indepedendent of Vds. Respectively supplying the IR2110 with Vcc of 12 V will handle all possible situations. Review a mosfet datasheet in case of doubt.
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 Geeks, I am doing a 250V 50Hz 500W bipolar spwm inverter project using Atmel microocntroller .I successfully generated signals and using look up tables to control output voltage.Now the problem is when i apply spwm signals to the mosfet the mosfet does not turn fully on.I checked the gate voltage it is around 3.15v (Vavg) at spwm duty (...)
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.