Other Parts Discussed in Thread: TPS25751
Tool/software:
Hi,
I have previously communicated with Christopher Lim on this subject:
Using the evaluation module, I have not been able to charge beyond 4 A. We had a separate discussion about that earlier.
I now have my own design with TPS25751 for USB-C front-end, and a 2nd 20VDC input switched into the VBUS input of the charger by two external back-to back MOSFET circuits (excerpt below)
I am able to write the configuration file that I generate using the online config tool, into the EEPROM and able to negotiate 20V from USB-C, charger switches to the USB input and charge up to 4A with USB-C port connected (PPHV above)
When the 2nd input is connected (UAI-20V above) only, meaning USB-C input is disconnected, charger switches to the 2nd input. ACDRV2 asserted, MOSFET is switched, I measure 20V at VBUS input pins. Good.
BUT charger never comes ON! What am I missing? Is the charger not supposed to charge from the 2nd input? I do not se any mention of that on the data sheet.
Thank you,
_Iz