The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 11, 2001
Filed:
Jul. 25, 2000
Serban-Mihai Popescu, San Jose, CA (US);
O2 Micro International Limited, Grand Cayman, KY;
Abstract
A power management circuit for battery systems composed of a switch defining a single charge/discharge path. The switch is selectively controlled using analog signals to couple a battery to a power source for charging, or to couple the battery to an active load. For charging, the switch is controlled by a controller circuit that monitors the battery voltage, the power source and the individual battery cells. The battery is only coupled to the power source if it is determined that the power source is present and that each of the battery cells is capable of receiving a charge. During discharge, the controller monitors the discharge current from the battery and compares this value to a threshold current. If the discharge current falls below the threshold, the switch is controlled to decouple the battery from the load. In this way, an overcharge condition is avoided if, for example, a power source is reapplied to the system. In a multiple battery system (where the battery and battery circuits are connected in parallel to a load and a power source), the use of the threshold current prevents a cross-conduction between batteries.