The USB-IF has at times specified 4.4V as minimum and 5.5V maximum, but that doesn't matter much; the Pico and Pico W use a buck-boost regulator which should mean they are usable for operation with VBUS between 2V and 5.5V.for a serious project 4.6V would give me the jeebies. Minimum VUSB measured upstream is 4.75V in the USB standard.
But, yes, the divide-by-two resistor divider on VBUS may not provide a high-enough signal to indicate power is connected at low voltages. I agree the CYW43's GPIO digital inputs are 0.8V/2.0V, so powering below 4V may cause issues. Not expected over USB but could be seen with external power connected to the VBUS pin.
Statistics: Posted by hippy — Wed Jul 17, 2024 11:59 am
