CHARGING CONTROLLER PROVIDING CONSTANT-CURRENT MODE AND CONSTANT-VOLTAGE MODE

摘要

A charge controller is provided to improve a safety level of a charging process by maintaining a control device charging voltage at a constant value after the charging process is completed. A charge controller includes a pull-up current source(I_up), first and second amplifiers(A1,A2), and first and second control transistors(Mc,Mv). The pull-up current source is inserted between a control node and a first voltage. The control node is connected to a control terminal of a power transistor. The first amplifier amplifies a difference between a charging current voltage and a first reference voltage and outputs the amplified voltage difference. The first control transistor turns on/off a second voltage in response to a first difference voltage which is outputted from the first amplifier, and selectively turns on/off the second voltage. The second amplifier amplifies a difference between a device charging voltage and a second reference voltage and outputs the amplified voltage difference. The second control transistor selectively turns on/off the second voltage in response to a second difference voltage which is outputted from the second amplifier.