Single-Cell Li-poly Overdischarge Protection ICs for <200mA, 3V Cutoff, Low Quiescent Current

Hello all,

I work on a project where we use 1 cell Li-poly battery (without protection). The battery is embedded in the device with a charger (MCP73831). I need a circuit that is able to protect it against discharging under 3 V. Currently I use circuit MCP112 + MOSFET which makes the job but I do not think it's the best way to do it. I believe there must be a specialized IC for it but I didn't succeed to find such one. The desired switching current is bellow 200 mA. The expected current from discharged battery is around 1 uA. Does anyone have more elegant solution than mine?

Thank you.

A possible performance drawback to using the MCP112 is the small threshold hysteresis. It may disconnect the battery but then reconnect it as the cell voltage rises under no load.

I looked at TI, Richo, Seiko, Linear Technology, and Maxim and didn't find quite what you are looking for, which is a single IC that implements undervoltage protection without an external MOSFET.

I would have to research this some more to come up with a definitive answer, but I would consider using a combination micropower comparator/voltage reference and a MOSFET. With that you have complete control over the undervoltage threshold and the hysteresis. An example of this type of IC is the LTC1998.

You can check for its performance. There are serious safety issues with the current lithium-ion batteries that are used in electric and hybrid automobiles. However, a research firm states that it has discovered a way to make a safer battery that can create a longer driving range by utilizing a solid electrolyte instead of a liquid one.

Thank you for your opinion. I understand the comment about the small hysteresis - fortunately I haven't encounter such behavior.
I have a little current and I can affect it by measuring the voltage and disabling some functions.
Thank you also for the hint with LTC1998, it seams to be more specialized for my needs.