Q)over current detection circuit

[asicpark]

over current detector circuit

Hi All,

I am going to desgin the over current detection circuit to diable the drive funtion when the current goes over some limit(maybe 2~300mA).

It should be needed low operating current and quite precise level.

For now, I am thinking some circuit using sense element with metal resistor in power line. The each side of voltage across the metal resistor are each input of a comparator. But, I think it might be only tens of mili volt (40mohm*300mA), so I wonder it would be fine to detect the level.

If someone who have an idea for this, please let me know.

P.S. I also need 2u current bias to operate under 1.2V.

Thanks,

 

[sunking]

over-current detecting circuit

sample the current (such as 5u) and change to voltage for a compartor