Problem with reset in power line interrupt circuit

[saurav_sdpl]

I have designed a power line interrupt circuit which should occur at least 200mS before reset.

Vin=4.5V
Vout=3.3V
Cout=1000uF
cin=4.7uF

Interrupt is given through a transistor BC847 from low-to high, with 4.5V connected at base.

I am using TPS3823 as reset IC.

When i analyze it i see reset ocuuring before PDD.

I am not able to understand the reason
plz suggest

 

[arturt134]

Re: Power line interrupt

Need more info about hardware. Please send any schematic.

But, for the first look, try to change hardware to generate interrupt on high->low edge, or low level. When the power is falling, there may be not enough voltage to generate high state.

Regards.

 

[mg_designs]

Power line interrupt

trinng to change hardware to generate interrupt on high->low edge, or low level is good sugget