Other Parts Discussed in Thread: BQ24780S
TCA9517-Q1Hi,
In my application, I have a battery charger chip (BQ24780S) and a battery BMS (some BQ chip I don't know precisely) talking together on a shared SMBus, and a FPGA sending some requests from time to time. There is a condition where the FPGA is powered OFF while the battery and its charger are still communicating. I would like to use the TCA9517-Q1 to "isolate" the FPGA from the rest of the bus when powered OFF.
As I don't want the TCA9517-Q1 to sink current on the battery, I plan to power both A and B sides with the FPGA 3V3 network (i.e. both sides can be powered OFF at the same time). The A side would be connected to the charger/battery network while the B side would be connected to the FPGA. The pull-up resistors on the charger side would not be polarized by the A side power, but to a "permanent" 3V3 issued from the battery, because I need the charger to keep on working with its battery even when the FPGA 3V3 is down.
Can I do that ?
In such condition, if reliable, what leakage current would sink the SDAA and SCLA pins ?
Is there a better way to "unplug" my FPGA from the SMBus without consuming energy from the battery ?
Thank you by advance !
Cyril
