I'm looking for small PCB footprint solutions to charge a 45mAh LFP battery for a wearable device.
BQ25071 looks suitable except the datasheet specifies a minimum current of 100mA, but doesn't go into any detail about where that limit comes from, or what might occur if I try to set it lower.
What happens if I set a current of 20-50mA by simply using a larger Rset? Will the charge current simply be somewhat inaccurate (which I can deal with), or will some more problematic issue occur?
The internal diagram seems to show a dividing current mirror from an input current monitor, with an op-amp [ Iin(reg) ] to limit the current if the voltage at Iset exceeds 1.5v. Why would this arrangement have a minimum current?
Could I insert a resistor between OUT and GND with diode to BAT if simply putting a larger Rset somehow won't work?
Are there any parts that might be more suitable for my application?
