Hi,
we are using the BQ24600 to charge a 22.2V Li-Pol battery (6S).
At the beginning, it was working quite well, but after many tests, the BQ24600 is now defectuous.
In fact, the input SRN (pin 9) is shorted to the ground. The low side MOS has burned too, as the Rsns.
This problem happend after many hot plug of the battery.
Did you ever seen this kind of problem?
What can be change to avoid this kind of problem?
Best Regards
Frederic
Hi Frederic,
Have you found a solution for that hot plug issue? This would be really interesting since I'm struggling with the same problem!
I'm working with a 22,2V, 5Ah Lithium battery. When connecting the battery to the charger I can hear the current rushing into the circuit since all capacitors are uncharged. This worked out a few times but now the BQ24600 is defective. You can also see a tiny hole on its surface right in the corner above Pin 8, 9, 19 (VFB, SRN, SRP) now.
So I put my focus on those Pins and a simulation has shown that there is a voltage overshoot on VFB and SRP. I'm simulating a battery plugin with a voltage rise from 0V to 25,2V in 1ns. I'm also simulating the inductance of the sense resistor (10nH) which I think is responsible for the overvoltage on SRP.
This is my circuit:
My question is how can I avoid those overshoots? Should I place a TVS-diode (like 1V11) close to the IC?
Best Regards,
Stefan
