I am working on a device that is to use a 2S1P Li-ion pack. The hope was to avoid contributing to the clutter of wall warts, so USB became the recharging option. However, shortage of chips, especially of charger ICs, especially of USB charger-ICs, especially of USB-C charger-ICs, has dashed that hope. Add high prices to the mix!
Pretty much the sole option left for me is the mp2762a (which alas is not stand-alone, but uses i2c). This actually lists USB as a source option. However, the data-sheet is ambiguous about that. Is it legacy USB ports? I certainly don’t expect USB-C.
I see no CC1/CC2 or even D+/D- pins. So, AFAIK, no negotiation (‘enumeration’) can take place, leaving the current at 100 mA. Is this so? Even if i2c can set limits, my vague understanding of USB is that the negotiation is driven by the source, not the sink.
I’d be grateful for any light anyone could shed on this.
I’ve even thought of combining different ICs, but the risk+overhead would be excessive.
Thanks in advance!