Hi support team
I am using BQ24600 IC in charger for drones.
I used schematic from datasheet (Icharge = 3 A, Ipre-charge = Iterm = 0.3 A) with little changes:
I use 6s battery, so I change VFB voltage divider to 1M1 and 100k resistors
On TS pin is voltage divider 470k and 470k (only for testing)
T1 and T2 is AOD444
Inductor is 3,3uH with saturation current 8A
First I connected battery through 20 Ohm resistor. Everything look good (Vref 3.3V, REGEN 6V, CE high, battery voltage 22V). Current from power supply was about 200mA and IC indicated charging. Charger worked in Non-Synchronous mode.
After this test I replaced 20 Ohm resistor for 5 Ohm. I connected charger to power supply and current from power source was obout 750mA and IC indicated charging. After few seconds of charging bottom transistor burned down. IC did not work anymore.
I was looking for some errors on PCB or schematic but I did not finde anything. I think, that transistor burned down because it was open too long.
Can you help me with this problem?
Thank you
Jozef Augustin
