Patent ID: 7705661
Filing Date: 2010-04-27
Classification: G05F

Abstract:
1. A current control apparatus applied to a transistor having a control terminal, a first terminal, and a second terminal, the current control apparatus comprising: a current control module, for outputting a current control signal; a first current mirror module, having a first output terminal, a second output terminal, and an input terminal, the first output terminal being coupled to the first terminal of the transistor, the input terminal being coupled to the current control module, and the first current mirror module utilized for generating a first current mirror current and a second current mirror current respectively at the first output terminal and the second output terminal in accordance with the current control signal, wherein there is a predetermined current ratio between the first current mirror current and the second current mirror current, and the transistor generates a second current at the control terminal in accordance with the first current mirror current; a second current mirror module, having a first terminal and a second terminal, the first terminal coupled to the control terminal of the transistor, and the second current mirror module utilized for generating a third current mirror current at the second terminal of the second current mirror module in accordance with the second current, wherein there is a predetermined current ratio between the second current and the third current mirror current; a current subtractor, coupled between the second output terminal of the first current mirror module and the second terminal of the second current mirror module, utilized for generating a third current in accordance with the second current mirror current and the third current mirror current; and a current adjusting module, coupled to the current subtractor, utilized for adjusting the third current to a fourth current, wherein there is a fixed current ratio between the fourth current and the third current.