External Voltage Reference Pin

[mlibby]

Hello, I want to use an external voltage reference of 2.5V for ADC, but I have not found in the documentation what the pins are for connecting this device. Any help please? Also what changes in registers are required to use that external Vref? Thank you

[Sprite]

Sorry, the ESP32 does not support an external reference voltage.

[mlibby]

Thank you, then how to access the internal voltage reference and what is that value? Also what is the +/- voltage range for the analog channels inputs?
Best regards