CSD21520 broke!! why?

Hi Serghei,

I have asked one of the applications engineers from the drivers team to respond to your question. It would be useful to provide some more information like gate drive waveforms and the part number for the mosfets.

Regards

Peter

I use csd18540 also from TI.

UCC21520 v2.7.pdf

Thanks very much, Peter,

Serghei, I am Wei and I will help to support you on the UCC21520. After reviewing the information, I have a few comments:

1. Was the Driver broke with Low Voltage (VCC, and 13V) only or it was broke when 65V was applied?

2. If it was broke with only only Low voltage, I think it might be a soldering short issue somewhere.

3. If it was broke with 65V applied, it is better to see the waveforms. I will advise which waveforms to catch after you confirmation.

Thanks a lot.

Wei

Its broke on ~65V with low load few Amps max 2A.
2. After output I put immediately 10 Ohm resistor. to protect driver. 13V => ~ 1.3 A is not much, correct, and on oscilloscope wave form is good, before broke :).

I think short to GND on any side circuit is not case on mine. Green is High side , Yellow is low side directly from nexfet Gate. 

I try to put oscilloscope next time and monitoring all lines High side low side and 13V.

Hello Serghei,

How is going with the debug? Does it continuely burn the parts?

if so I recommend the following suggestions:

1. Instead of runing continuous pulse, would you please send double pulse or a limited number of pulses to make sure we can see the abnormal waveform without hurting the circuit badly.

2. The following waveforms is a good choice.

a. HI, b. HO-HS(Differential probe), c. HO, d. LO, e. Inductor current.

I look forward to your reply.

Wei