O2Micro granted US patent for over-voltage controller

USA: O2Micro International Ltd, a global leader in the design, development and marketing of high-performance integrated circuits and solutions, was issued seven claims under United States patent number 8,232,773 for its Over-voltage Transient Controller; a continuation of the invention issued September 2009 under United States patent number 7,589,499.

Pre-charging (charging battery cells with a very low current) is required when a Lithium Ion rechargeable battery pack is too cold or deeply discharged. O2Micro's patented controller architecture enables lower cost pre-charging, without increasing the board size.

The patented architecture enables "adaptive" pre-charge to increase the charging current as the cell voltage increases, until finally reaching the full charging current level. Prior art utilized a fixed charging current, taking a longer time to charge the battery pack.

"Rechargeable battery applications include laptop computers, PDAs, cell phones, and any portable electronic device," said Bill Densham, strategic marketing director, O2Micro.