I am really sorry, I can't share whole schematic due to restriction.
In schematic:
There is only a IC that is connected between battery and power supply and output is labeled with "VBAT". No IC is mentioned for +3.3v, VDDIO pin.
In datasheet:
They have mentioned:
Power Supply:
LDOIN is 3.3V to 5.5V
VDDIO is 3.0V to 3.6V
And also found that voltage of I/O pins are rated when VDDIO is 3.3v.
Do schematic mean that it has only one power supply?
Or they have forgotten to add voltage regulator for VDDIO pin.
I asked to company but it'll take long to answer due to heavy traffic.
impossible to answer without schematic and datasheet.
***
It´s like asking a taxi driver for the cost to visit your friend. But you can´t tell him the addres of your friend because it is a secret place.
A dilemma only you can solve.
The VDDIO pin may be a "tap" from an internal LDO
that allows an external decoupling / reservoir for
internal pulse loads and pin load steps.
But really you ought to at least read the datasheet
for yourself as it probably addresses this question,
either in application figures or in description text.
Hello carl5,
It seems to me Pins 13 and 14 are connected to 1uF bypass capacitors and are not directly
connected to any voltage rails.
C12 in Pin 13 with a value of 1uF.
I cannot see the cap number on Pin 14, but that has a value of 1uF as well.
Regards,
Relayer
Sorry guys, I realize this thread was solved, but I didn't want anyone to miss the obvious...