My objective:
I'm designing a charging station that need to charge 100+ single cell Li-Po battery together. L6924D fits all my requirements like it can specify the charging current, termination current and max charging time.
My challenge:
Since the battery is cylindrical cell and both polarities of the battery pack looks exactly same with only a plus and minus marking. There might be a chance to insert the battery in reverse polarity. Also, my customer decided to keep the hardware fixture and no chance to modify it.
My problem:
The L6924D datasheet mentions about the "reverse blocking diode" inside the IC, but there is no section to explain how the blocking diode works. Does it means that the IC has the ability to protect itself from reverse polarity battery?
I had tried to test it by connect a reverse battery between the IC's Gnd and Vout (shorted to Vosns). The IC survived if I limit the input supply current to 400mA (my charging current is 200mA, so it runs on linear mode). However if I raise the input current to 500mA then the IC burned by drawing all 500mA into the IC. Is there any limitation about the blocking diode or I miss understand the things since reverse blocking not equal to reverse polarity protection?
