Patent ID: 9391467
Filing Date: 2016-07-12
CPC Classification: H02J

Claim Text:
1. A battery charger, comprising: a) a step-up converter configured to generate an output signal by boosting a DC input voltage, wherein a threshold voltage is greater than said DC input voltage; b) a charging control circuit configured to receive said output signal from said step-up converter, and to control charging of a battery; c) said charging control circuit being configured to regulate said output signal by a power transistor operating in a linear region to maintain a charging current for said battery charging as a trickle current when a battery voltage is less than said threshold voltage, wherein said power transistor is coupled between said step-up converter and said battery; and d) said charging control circuit being configured to charge said battery directly by said output signal by said power transistor operating in a saturation region when said battery voltage is greater than said threshold voltage.