Part Number: BQ76200
Hi,
I'm studying ref design TIDA-010030 (13s BMS based on BQ76940 with high side fet drivers and gauge). It implements a pre-discharge path with 300 ohms bleeding resistor in parallel to the discharge FET. I saw this before in other BMS boards, even with much smaller resistor values.
I read the datasheets, and understood that this is useful for discharging a high capacitive load for detecting load removal, to reestablish the system in case of a fault..
1. In the circuit, I can't understand the current path, when activating the pre discharge fet, that will discharged a capacitor in the load. How is it works?
2. When should I activate the fet? Only in case of SCD or OCD before I try to activate FETs again? Should I sense in that case PACK+ terminal through TIDA-010030 waiting for a condition? What would be that condition?
I'm sorry about these questions, I really tried to figure them out and still can't understand it.
Kind regards.