UVLO for multicell LiIon battery

[rakeshm55]

Hi,
I plan to use 28V Liion battery  to power my system. I wish to have UVLO feature implemented so that deep discharge of battery could be avoided..I expect UVLO to have threshold of 24V with a 2-2.5V hysteresis...

By battery is connected to Push button controller LT2955 ... How to implement UVLO feature?? is there any standard circuit??

please let me know....

[mvs]

By battery is connected to Push button controller LT2955 ... How to implement UVLO feature?? is there any standard circuit??

You can use /KILL input to implement UVLO, just add voltage divider. Hysteresis will be 24*0.03/0.8=0.9V.

[rakeshm55]

So for 512ms the device will remain on before kill triggers...
I have about 400uF capacitor connected to this supply with inrush current limited to 3A....So this 3A for 30ms or about  will it be a stress on battery ??....For rest of 512ms the board will be in the process of waking up OS...by this time power will be removed immediately ... Abruptly halting booting process ...

[mvs]

For rest of 512ms the board will be in the process of waking up OS...by this time power will be removed immediately ... Abruptly halting booting process ...

You can use some voltage supervisor to block push button operation of LT2955 and send interrupt to your OS for graceful shutdown.

PS At some stage it makes more sense to discard LT2955 and use low power 8-bit MCU to control custom requirements. You will probably need some sort of low level control also for charging, etc.