Hello everyone,
We're working in a design with the STM32L151ZE and a power supply of 3V. We're trying to design a connector able to detect when specific resistances are present.
I've seen that there are some inputs of the chip that are 5V tolerant, where the max voltage should not go over 5.5V.
We're trying to design a voltage divider consisting on a supply of 5V, a fixed resistor from 5V to the ADC input pin and a connector from the ADC input pin to GND. We're thinking of placing in the connector different resistors in a way that the minimum resistor makes the voltage divider pin to drop to 2.9V, and every other resistor will make the voltage to drop to values under that.
My question here arises as we would like to know if there will be any problem if we connect the ADC input pulled up to the 5V supply (when no external resistance is placed on the connector) and we perform a reading. I don't know if something inside the chip can be damaged or it just will output a 100% value of the analog voltage. This last option is already considered (that's why we're designing the voltage divider to be 2.9V, being the chip supplied at 3.0V and also the Vref pin at 3.0V).
Many thanks for your time. Regards,
Manuel
