Hi,
I’m designing a device, that can work (and communicate) on USB cable or standalone supplied by LiPo parallel cell array for a long time. I chose MP2632 chip, because it seems perfect to hit my goals: charging cells with 3A current, leds showing battery status and push-button operation to switching device on and off.
I’m asking for help, because during tests of assembled prototype, I encountered some problems.
- Behaviour of status LEDs. Datasheet stated, that during boost operation, after pushing button LEDs are indicating battery status for 5 seconds. Instead of that, one diode is constantly one diode is constantly lit and pushing button does nothing.
- My device is using USB-C connector to be more modern compatible, but using standard USB 2.0 protocol. When connected to high-current chargers with USB-C to USB-A and USB-C to USB-C cables, charging works fine. When connected to computer with USB-C port, device is charging and communicating with data transfer (FT232 chip connected directly to DM and DP ports, parallel with DM1 and DP1 of MP2632). But connected to USB-A port with USB-C - USB-A cable, device supply gets hiccups. It seems like MP2632 is trying to get full charging current immediately after connecting, without negotiating current with computer first. I checked that when doing this with unattached battery, connection goes without that problem, and when battery is attached after connection ewerything still works fine and battery is charged. What can be cause of this problem?
Additionaly to topic, I have two questions:
- I read on this forum, that there is possibility of working without power lose when attaching or detaching external power supply, using some external circuit. Can I ask for help with that?
- What actually is “torch-light control”? I must confess, that I can’t understand this function when reading datasheet.
I will be gratefull for help, also I’m very sorry for lots of text, but I hope it will be helpful in understanding my problem.