Dear Support,
I have a question pertaining to the BQ25890 and the ilim hardware pin. I have a current design where the microprocessor is not required to be on to charge the device. Under this scenario I was relying on the hardware ilim resistor to limit the battery current. By default and watchdog reset, the BQs charge current default is set to use 2 Amps to charge the battery. This is a little too high for my application. I had sized the ilim resistor to prevent charge current from being too high for my particular battery assuming a typical 5V USB input. With maxcharge and HVDCP enabled by default, will I have a potential problem if a high voltage charger is used prior to the microprocessor being turned on for the first time, or after a power on reset due to a battery swap?
For example. With an ilim set to a maximum input current at .9A on a 5V input power there is 4.5W of charging power. Assuming perfect efficiency and the battery has just left pre-charge state, this is still below my battery’s charge limit. However, If maxcharge or HVDCP are negotiated, the power may go up to 10.8W.
Am I correct in assuming that this higher power converted to charge the battery may be an issue, if the processor has not yet lowered the fast charge current registers?
-Jam