Hello. I'm experiencing battery charging IC problems. After a few charging cycles and hours of use of IC, it burns out. In screenshots, there is a schematic of circuits and there is also a PCB design. Whole device is charged with a USB port in the computer and often during charging it is Turn On, which should not be a problem. I went through the datasheet and can't see any possible mistake. Can you help me out?

 

Your IC may be over heating and burning out.
Use your finger and touch the IC for signs of overheating. Do it immediately on switching on so you don't touch an overheated IC and burn your finger.

 

Your IC may be over heating and burning out.
Use your finger and touch the IC for signs of overheating. Do it immediately on switching on so you don't touch an overheated IC and burn your finger.

I used Thermo camera and there is definitely some heat, but according to IC datasheet, it should be within tolerances - as it has about 50°C when operating. It was the reason why I put a current limiting resistor that IC should charge with half of the prescripted possibility.

 

IC has internal fold-back current limiting so shouldn't be able to burn out. Are you sure its actually burning out and there's not something else going on?

 

IC has internal fold-back current limiting so shouldn't be able to burn out. Are you sure its actually burning out and there's not something else going on?

Thanks, Irving for your reply. Burnout is my conclusion, however, there could be something else going on. Another option was that there have been small spikes on the USB port when turning on charging. There was a short spike up to 6,9V. I tried to put on main power line a bigger capacitor 22uF and it helped with the spike. Could that be a problem? What else could it be?

 

there have been small spikes on the USB port when turning on charging. There was a short spike up to 6,9V.

That doesn't sound right. The USB is being fed from what? Is that J3?

 

That doesn't sound right. The USB is being fed from what? Is that J3?

Yes, I use USB cable to Jack barell.

 

Given the absolute maximum input to that chip is +7v, and that a spike of 6.9v is likely to be much higher, this could be the source of the problem. Are you running this from a PC USB port or a dedicated charger 'wall wart' that has quick charge capability?

 

Given the absolute maximum input to that chip is +7v, and that a spike of 6.9v is likely to be much higher, this could be the source of the problem. Are you running this from a PC USB port or a dedicated charger 'wall wart' that has quick charge capability?

It's PC USB Port. I've tried to change main power line capacitor from 10uF to 22uF and spike doesn't get higher than 6V so I'll try ti to test it fr longer period of time.

 

Try a Tranzorb diode in parallel with the voltage input, like the 1.5KE6.8A