I am working on a custom curcuit that has 2 different voltage outputs i need to protect from accidental voltage input up to 18v.
1. My project has a 5v ouput that runs to a sensor and i would like to protect this from higher voltages flowing back to the voltage regulator and microcontroller. I realise a diode would be very easy but would really like the 5v output( yes 4.7v after diode voltage drop would operationally be fine but im mostly interested in how this can be done as i just cant figure it out).
2. I am using the teensy analog pin to controll an opamp to then output a 0-5v signal. I would like to provide the same protection from current flowing backwards with this too.
I can find lots of designs using mosfets to prevent reverse current but im under the impression that in my use these will not work as although the drain of the fet might have 12v and be over voltage the source would still be at 5v and be over voltage.
The best solution i could find was this http://www.ti.com/lit/ds/symlink/lm74610-q1.pdf which i wasnt sure of its operation but then i read that it has no ground pin so without a ground pin it really has no option but to prevent reverse current does it ?
1. My project has a 5v ouput that runs to a sensor and i would like to protect this from higher voltages flowing back to the voltage regulator and microcontroller. I realise a diode would be very easy but would really like the 5v output( yes 4.7v after diode voltage drop would operationally be fine but im mostly interested in how this can be done as i just cant figure it out).
2. I am using the teensy analog pin to controll an opamp to then output a 0-5v signal. I would like to provide the same protection from current flowing backwards with this too.
I can find lots of designs using mosfets to prevent reverse current but im under the impression that in my use these will not work as although the drain of the fet might have 12v and be over voltage the source would still be at 5v and be over voltage.
The best solution i could find was this http://www.ti.com/lit/ds/symlink/lm74610-q1.pdf which i wasnt sure of its operation but then i read that it has no ground pin so without a ground pin it really has no option but to prevent reverse current does it ?