i'm using a MKE15Z128VLL7 with available VREFH pin. VREFH will be connected to a 4.096V shunt precision reference (LM4040).
I have to create a project that allows the system to be brought to an ultra low power condition. For this reason, when I put the MCU to deep sleep I would like to turn off all peripherals including the shunt precision reference. Essentially there will be a battery supplying the 5V to the MCU VDD pin and shutting down the 5V that goes elsewhere.
From datasheet it shows that the minimum voltage of VREFH is 2.5V, I wonder if for some reason I can damage the MCU if I bring it to 0V.
Solved! Go to Solution.
It's an interesting solution. But using shunt reference voltage like LM4040 it have relatively high quiescent current even if the voltage is lower than the reference voltage
I'm considering using a nano power reference voltage like REF35 that has a quiescent current below 1uA
Adding the diode in series to the reference voltage makes it meaningless. This is because the quality of the reference is subject to the fall of the diode and therefore not very precise and accurate