Patent ID: 8143845
Filing Date: 2012-03-27
Classification: H02J

Abstract:
1. A battery charger comprising: a transformer having a primary winding and a secondary winding; a transistor coupled to the primary winding of the transformer, the transistor being configured to couple the primary winding to ground when the transistor is ON and to decouple the primary winding from ground when the transistor is OFF, the transistor being configured to receive an inductor current through the primary winding when the transistor is ON; a comparator having a first input node and a second input node, the first input node of the comparator being coupled to receive a sense signal indicative of the inductor current, the second input node of the comparator being coupled to receive an error signal, the comparator being configured to generate at an output node of the comparator a control signal for controlling switching of the transistor by comparing the sense signal to the error signal; and an error amplifier having a first input node and a second input node, the first input node of the error amplifier being coupled to receive a reference voltage that changes as a function of the error signal, the second input node of the error amplifier being coupled to receive a sampling of an output voltage generated by the battery charger to charge a battery by way of a charging cable, the error amplifier being configured to generate the error signal at an output node of the error amplifier by comparing the sampling of the output voltage to the reference voltage, the error signal being indicative of a level of the output voltage, the error amplifier being configured to compensate for voltage drop on the charging cable by having a predetermined and limited DC gain.