Ir2153 based smps mosfet failure

Thread Starter

rahul411

Joined Feb 19, 2018
260
hi there,
i did some measurement on oscilloscope and the results are,

this is the clock signal on pin 3
IMG_20190916_111925.jpg



output waveform on pin 5 (LO)
IMG_20190916_111935.jpg




output on pin 7(HO) this should also be a square wave with alternate switching time, but what is this mess? is this because the IC is damaged or anything else.
IMG_20190919_130242.jpg
check out the pin7.rar file, it is a video of waveform (if it is necessary)


and the waveform on pin5 gets distorted when i connect the mosfets, mosfets are in good condition. for this mosfetconnected.rar file. in that you'll see as soon as i connect the mosfets the waveforns get too distorted that it is not a square wave anymore.
 

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Alec_t

Joined Sep 17, 2013
14,280
If, as shown, you're getting 2.38kV peak-to-peak on pin 5 (LO) I'm surprised the IC or the FETs have survived!
For security reasons I don't open rar files.
 

Thread Starter

rahul411

Joined Feb 19, 2018
260
If, as shown, you're getting 2.38kV peak-to-peak on pin 5 (LO) I'm surprised the IC or the FETs have survived!
For security reasons I don't open rar files.
Lol.. something is wrong with the settings of oscilloscope as it is from my college and so it's for public and not everyone knows what to do with all those buttons on there, so they press them for no reason.
I'm using 17V dc to power it and not actual mains supply. You can have a look to those videos they are safe.
 

Thread Starter

rahul411

Joined Feb 19, 2018
260
I read something related to this, that i will need a differential probes to see the waveform on pin 7 wrt pin 6
 
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