Lithium-ion (Li+) rechargeable batteries have gained the attention of portable electronic equipment manufacturers because of a 70% increase in specific energy (150 W-hr/kg) over nickel based chemistries. Unlike NiCd or NiMH cells, Li+ cells require in-pack electronics for protection against inadvertent electrical over-stress. The topic of this paper is the micro-power design techniques utilized for an in-pack protection IC that is powered continuously from a single Li+ cell without significant discharge of the cell