Hi, guys !
I have this schematics... It gives me a high level when my battery voltage drops under a threshold. For this I need a stable voltage reference... I choose LT1790... The problem is that I want to add hysteresis to this comparator. And the only way I know is by connecting a high impedane resistor to the non-inverting imput. For this hysteresis to work, I need to put a voltage divider to the reference, because if i connect directly the IN+ to the reference it won't work. Ok, but now, the opamp si powered from 12V and it will output 12V when signaled, and that voltage will go to the 5V reference output through the 1Mohm and 47K resistors. In simulation the circuit is working, but I don't know if the LT1790 is safe in these circumstances ? Won't a current flow from the 12V to the 5V ? In the simulation there is 54uA at the output of the reference when the comparator is low, and when the comparator turns high, the curent from the reference output drops to 48uA... But is not negative or else...

I have this schematics... It gives me a high level when my battery voltage drops under a threshold. For this I need a stable voltage reference... I choose LT1790... The problem is that I want to add hysteresis to this comparator. And the only way I know is by connecting a high impedane resistor to the non-inverting imput. For this hysteresis to work, I need to put a voltage divider to the reference, because if i connect directly the IN+ to the reference it won't work. Ok, but now, the opamp si powered from 12V and it will output 12V when signaled, and that voltage will go to the 5V reference output through the 1Mohm and 47K resistors. In simulation the circuit is working, but I don't know if the LT1790 is safe in these circumstances ? Won't a current flow from the 12V to the 5V ? In the simulation there is 54uA at the output of the reference when the comparator is low, and when the comparator turns high, the curent from the reference output drops to 48uA... But is not negative or else...

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