Hi all,
I need your help in designing a battery removal detection circuit.
My handheld device is powered by 2XAA batteries.
The signal should be as an interrupt to the MCU and it can't take more than 50uA.
I tried to use P-channel mosfet (S- connected to batteries and interrupt to MCU, G- GND, D- to power supply) but the problem was that the power supply has high capcaitors on the input that cause the mosfet never to turned off, than the drain and source voltage were the same all the way during the voltage decay.
I'm looking for solution that will apply fast interrupt to MCU when removing the batteries so that the MCU will be able to shout down the system correctly.
I thought using the FPF2125 load switch that contains reverse current blocking but the problem is that the input to the IC requires an 4.7uF capacitor, so still I have the same problem.
I need your help in designing a battery removal detection circuit.
My handheld device is powered by 2XAA batteries.
The signal should be as an interrupt to the MCU and it can't take more than 50uA.
I tried to use P-channel mosfet (S- connected to batteries and interrupt to MCU, G- GND, D- to power supply) but the problem was that the power supply has high capcaitors on the input that cause the mosfet never to turned off, than the drain and source voltage were the same all the way during the voltage decay.
I'm looking for solution that will apply fast interrupt to MCU when removing the batteries so that the MCU will be able to shout down the system correctly.
I thought using the FPF2125 load switch that contains reverse current blocking but the problem is that the input to the IC requires an 4.7uF capacitor, so still I have the same problem.