Hi everyone, I try to make this circuit (Solar panel and supercapacitors - #51 by gromit1) with TPS3839 voltage supervisor and I want to add a voltage divider after the RESET pin to protect the ESP microcontroller. So I have a few questions.
What is the maximum voltage that ESP8266 / ESP32C3 can handle on EN pin?
If it's only 3.3V then am I right that I only need one resistor connected to GND from the RESET pin because the other resistor in the voltage divider is already in the circuit, the one which is connected to the VDD pin (R1).
What happens to R2? There is 0.4V voltage drop compared to VDD in the voltage supervisor. Does it influence the voltage divider I want to use? Is there an internal resistance of the TPS chip?(that would affect the divider)
The old post is closed unfortunately, I couldn't continue there. Post #51 is the only important. I didn't find resistance data in the datasheet.
I want to charge a super capacitor with a boost converter and a solar panel.
An LDO will be used to lower the supercapacitor voltage to 3.3V which is suitable to power the esp microcontroller. The voltage supervisor chip is there to deactivate the microcontroller if there is not enough voltage in the capacitor and the 2 resistor you see is for hysteresis, so the circuit won't turn on immediately as it reaches 3.3V but after it reaches 4V for example.
Can I reduce the voltage with an npn transitor? I would like to connect 3.3v to drain and the RESET pin to gate, source to GND.
For now I used a current limiting resistor in series with the RESET instead of R9(you can see in my previous post) but this doesn't work well neither the original circuit I posted.
