Hello. I’m designing a board that includes the BQ35100 battery fuel gauge. I would like to also include the LTC4420 part that provides power priority between V1 & V2 inputs and reverse polarity protection (for installing batteries in backwards). The BQ35100’s SRP & SRM will monitor current across the sense resistor that is hangs off the Battery (-) contact. The Battery (+) contact will be a direct connection (through a mechanical switch) to the V2 input on the LTC4420 part that provides power priority and reverse polarity protection. The V1 input is prioritized and is a USB input (5V nominal). When the V1's USB is avail and is has a valid range, the LTC4420 will output the USB +5V nominal. Can the BQ35100’s VIN be connected to the LTC4420’s VOUT if it is scaled down as required in the BQ35100 datasheet (as discussed in paragraph 7.3.1.1 in the BQ35100 datasheet)? The intent would then be for the BQ35100 to only be enabled (asserting GE) when the battery is powering the circuit (as controlled and output by the LTC4420 when the LTC4420's V1's USB is not avail or valid and the battery is ok). The BQ35100's intent would obviously not be to monitor when the USB +5V is output from the LTC4420. I would like to know if connecting the BQ35100's VIN to the LTC4420 as I described here would work and if this would cause any issues with the BQ35100. Please advise soonest.
Thanks,
Eric
