Charging Method and Circuit Using Indirect Current Sensing

Abstract

The present invention relates to a charging circuit and method for generating a charging current supplied to an output terminal (15) to which a battery (40) to be charged is connected. The charging current is indirectly sensed to generate a sensing current having a predetermined relation to the charging current. This sensing current is then compared to a generated predetermined reference current, wherein the charging current is controlled in response to the result of the comparison. Thereby, accuracy, system costs and power efficiency can be increased as a low-ohmic precision resistor is no longer required in the charge current branch of the circuit. Furthermore, the proposed solution enables a simple implementation of the circuit as an integrated circuit.

Dependencies are inferred from the claim text.