ESP 8266 ADC input when ESP powered off
Posted: Thu Feb 24, 2022 12:02 pmI just want to check if having a voltage on the ADC input of an ESP12E when powered off would cause a problem, I don't think it will.
I have a wakeup latch circuit driving the enable pin of an SPX3819 LDO to supply the ESP12 but I have a voltage divider from the L-Ion cell (4.2) connected to the ADC input, the divider is very high impedance (3M / 1M) to reduce current in standby to a minumum.
In the circuit +BATT is connected to the ADC input via 3M resistor with a 1M resistor to ground so the ADC input will always see the battery voltage or atleast a proportion of it.
I have a wakeup latch circuit driving the enable pin of an SPX3819 LDO to supply the ESP12 but I have a voltage divider from the L-Ion cell (4.2) connected to the ADC input, the divider is very high impedance (3M / 1M) to reduce current in standby to a minumum.
In the circuit +BATT is connected to the ADC input via 3M resistor with a 1M resistor to ground so the ADC input will always see the battery voltage or atleast a proportion of it.