Hey there, I am new here. I am working with MOSFETs IRFZ44N to be more specific. I am trying to switch it at 50 Hz. But Its output Waveform looks weird. There is no gate resistor. Vds is 12v . R_load is 750 ohm. I am giving Vgs 5v with arduino. There is no Inductos/Capacitor attached. I have connectrd 10 kohm resistor across gate and source.
Please post a plot of the gate voltage.
Here it is bro. Just to remind you that there is no gate resistor. I tried to change MOSFET too, but still getting same result.
You’re trying to control a device that requires a 10v gate signal but you’re only providing a 5 volt level. Perhaps that discrepancy might be the source of you difficulties.
It looks like the Gate is being driven via a very high resistance. Maybe there is something wrong inside of the MOSFET.
Check the Source waveform also.
Try reducing the the RLoad
You’re trying to control a device that requires a 10v gate signal but you’re only providing a 5 volt level. Perhaps that discrepancy might be the source of you difficulties.
Perhaps you are looking at a different datasheet? The one I'm looking on will has a threshold of max 4.0V...
Try reducing the the RLoad
You see the triangular wave because of the high R-load and the capacitance at the drain.
I replicated your circuit with a similar MOSFET IRFZ46N and load. I get a square wave output with a 5mA draw current.
Recheck all your GDS connections.
It looks like capacitor charging and discharging through precisely same resistance. Also knowing that it is 50Hz, it should involve huge capacitor or huge resistor. I can not see how it is possible to get such waveform with the components which were mentioned in any configuration possible. And it is not about gate drive.
Please post information about your power supply, how you are probing the output and everything else.
What is the highest frequency at which I can toggle this mosfet with load of 10K ?
What MOSFET should I use to switch it at 10 MHz with same load?
I often use IRF44Zs with 5V drive for light loads. I have just bench tested one. It passed 3A with a 250mV D-S drop.
With 5V on the Gate and the 750Ω load, D-S must be only a few millivolts.
Maybe the MOSFET is faulty in some way.
Time to show us some photos.
pic_173_6.jpg
even a cheap crap knock off in my stock wont produce such a weird Vd plot (even in BJT lines). i think what you got is a sheet crap knock off stock from an "immitator" who dont believe they will be judged in the afterlife. IRFZ44N should be doing fine up to more than 10A at 5V Vgs
https://www.vishay.com/docs/91291/91291.pdf let alone your 750ohm load.
Hey there, I am new here. I am working with MOSFETs IRFZ44N to be more specific. I am trying to switch it at 50 Hz. But Its output Waveform looks weird. There is no gate resistor. Vds is 12v . R_load is 750 ohm. I am giving Vgs 5v with arduino. There is no Inductos/Capacitor attached. I have connectrd 10 kohm resistor across gate and source.
Could it be your power supply impedance and too much capacitance on the load?
the load is 750 ohms?...16mA? that's not huge btw...
Also...if you're using an SMPS/ chink bench power supply try some other method.
Also, do know that, Indian shops don't handle mosfets properly enough to not damage them with static electricity.
I also think the power supply may have troubles driving the circuit. I'd put a capacitor between Vdd and ground to see if it makes a difference. Say, 100uF or more.
Do you actually have a ground connection between the Arduino and the MOSFET source?
Do you actually have a ground connection between the Arduino and the MOSFET source?
maybe in that case...it's switching because of mains background noise