Patent ID: 6163187
Filing Date: 2000-12-19
Classification: G11B,H03L

Abstract:
A charge pump circuit comprising:an output node through which an output current and an input current flows;a current source connected to a first source of power voltage and flowing out a constant current;a first current mirror circuit having a first current path connected between said current source and a second source of power voltage different in potential level from said first source of power voltage, a second current path connected between said output node and said second source of power voltage and a first parasitic capacitor connected between a first control node for said second current path and said second source of power voltage, activated with a first control signal of an active level, and responsive to a first potential at a first monitoring node between said current source and said first current path after the activation so as to vary a first current passing through said first current path and a second current passing through said second current path proportionally to one another;a second current mirror circuit having a third current path connected between said first source of power voltage and said output node, a fourth current path connected between said first source of power voltage and an intermediate node and a second parasitic capacitor connected between a second control node and said first source of power voltage, activated with a second control signal of an active level, and responsive to a second potential at a second monitoring node between said fourth current path and said intermediate node after the activation so as to vary a third current passing through said third current path and a fourth current passing through said fourth current path proportionally to one another;a third current mirror circuit having a fifth current path connected between said constant current source and said second source of power voltage and a sixth current path connected between said intermediate node and said second source of power voltage, and responsive to a third potential at a third monitoring node between said current source and said fifth current path so as to vary a fifth current passing through said fifth current path and a sixth current passing through said sixth current path proportionally to one another;a first switching circuit connected between said first control node and said second source of power voltage, and changed from an on-state to an off-state with said first control signal of said active level so as to charge said first parasitic capacitor through said first current path; anda second switching circuit connected between said second control node and said first source of power voltage, and changed from the on-state to the off-state with said second control signal of said active level so as to charge said second parasitic capacitor through said sixth current path.