Patent ID: 6686723
Filing Date: 2004-02-03
Classification: H02J

Abstract:
An apparatus for charging a cell that may be deeply discharged, comprising:a pass circuit that includes a first pass circuit input that is coupled to a power signal, a second pass circuit input that is coupled to a first node, and a first pass circuit output that is arranged to provide a charging signal in response an input received at the second input; a primary charging circuit that includes a first primary charging circuit input that is coupled to the first pass circuit output, a first primary charging output that is coupled to the first node, a second primary charging circuit output that is coupled to the cell, wherein the primary charging circuit is configured to regulate the pass circuit to charge the cell when the primary charging circuit is enabled; and a deeply discharged charging circuit that includes a first deeply discharged charging circuit input that is coupled to the first pass circuit output of the pass circuit, a first deeply discharged charging circuit output that is coupled to the first node, a second deeply discharged charging circuit output that is coupled to the cell, wherein the first deeply discharged charging circuit output is configured to regulate the pass circuit to charge the cell when the primary charging circuit is disabled.