Hey, i would like some assistance with my circuit. I need to design a current cut-off circuit that will disconnect when the current coming into the circuit exceeds 100mA. Also, i would are there any ideas of designing a voltage limiter circuit, it should not allow the voltage to be more than 3.3volts, these are protection circuits for a cpld.

 

I would think about using a SparkFun Low Current Sensor Breakout - ACS712. While the ACS 712 is actually a 5 Amp sensor the linked breakout board should offer up good sensitivity down to the 100 mA range using the onboard trim pots. This way for a little over $10 USD you have a fabricated turn key solution. Then drive whatever you want to remove power. As to overvoltage? I would think about just using a comparator.

Ron

 

Hey Ron,
Thanks for the reply, can how would you design the comparator circuit?

 

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