- Thu Dec 17, 2015 11:48 am
#36661
I have been programming mine while going direct off a LiPo battery (nominal 3.7v but in reality 4.2volts when fully charged) never had a problem.
I recall seeing one reference in the deep dark bowels of the datasheets that the die is up to 6v MAX tolerant but that was not consistent with all the other documentation so I thought it was a typo. That said, I have NEVER fried one and I have even had them running off 5v myself (dodgy, el-cheapo 5v-3.3v step-down converter was just letting it through as-is).
I still run them in production with a regulated 3v3 suply but I have even found that the I/O (on RX and TX) to be long term 5v tolerant on old ESP-01 connected directly to an Arduino Nano v3 compatible.