I am suspecting the high side and low side FET’s turned on at the same time, in either leg of the H bridge or both resulting in pretty much a direct short across the rail. It seems to happen when I connect the power, so I was thinking maybe the lowside pulldowns are too big and didn’t discharge the gate while the power was disconnected and then one of them were on when I reconnected the power. For a better experience, please enable JavaScript in your browser before proceeding. On the subject of clamping diodes: If they have a little internal resistance though that helps too.

Uploader: Vocage
Date Added: 10 November 2016
File Size: 66.47 Mb
Operating Systems: Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X
Downloads: 40204
Price: Free* [*Free Regsitration Required]

TSM CS, power MOSFETs – elpro Elektronik

Any idea what went wrong? This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. I am suspecting the high side and low side FET’s turned on at the same time, in either leg of the H bridge or both resulting in pretty much a direct short across the rail. The body diode will clamp it. If you want to use 1 ohm resistors that should be ok too as you can change them later once everything is working.

In theory, one could use the Mosfet’s internal body diode. I was running the unloaded motor at a frequency and would just change it in my code, so I disconnected the circuit from Vin, did the quick change in code, recompiled, reprogrammed the PIC and connected the Vin again, this took around seconds. That might prevent another blowout while you are doing the initial testing.


TSM 4424 CS

You must log in or register to reply here. To participate you need to register.

The resistors would be there for protection against non recurring cross conduction. Deadtime is the very short period one must have between the time a Mosfet is turned off and the time the opposite Mosfet is turned on. Did you try the scope and resistors yet?

Bacause I haven’t been doing any of that. On the subject of clamping diodes: Futterama Member Feb 6, Ah, yes, but one of the highlighted features of the FETs are this: Futterama Member Feb 7, That would help fe blowout from false turn on no matter how it occurred power up, power down, bad dead time setting, any false signal.

fft But think of it this way, if you have a 12v supply voltage and 1 ohm resistor the maximum current would be 12 amps. You can then look across each resistor with a scope to see if there are any large spikes which would indicate that the bridge is not being switched properly.

Fett practice, with the current levels you are working with, it may be better if an external diode conducts that current. Check as an example, the following driver, it has adjustable deadtime: But these seem pretty fast. The PIC hardware PWM module should prevent cross-conduction, but there is no dead-band delay, this must be provided in software.


I have had the circuit working just fine and my code seems to work like it should, I could run the motor at different duty cycles and different frequencies. Forums New posts Search forums. It might be difficult to control the power up and power down phases so you might want to see if your application can tolerate those 0. A fuse isnt a bad idea but sometimes they are not fast enough. You can always “deadbug” a resistor across G-S. Thread starter Futterama Start date Feb 6, I supose you could just divide the 12 volts down, but that will slow it down a bit so you would need to be careful on reversals.

Hi, A lot of things could have happened. You probably 4424 need to clamp the gate voltage on the PFET. By continuing to use this site, you are consenting to our use of cookies.