Patent ID: 6927610
Filing Date: 2005-08-09
Classification: H03K

Abstract:
1. A voltage ramp generator capable of linearly discharging a capacitor for slew rate control of a power driving stage, comprising: a decision-making element that is provided with a reference voltage and an output voltage of the capacitor and is coupled to a first supply voltage and to a second supply voltage, wherein the capacitor is coupled to a low impedance voltage; and a cascoded current source that is coupled to the output voltage of the capacitor and the first supply voltage; wherein when the decision-making element detects that the output voltage of the capacitor has discharged to a predetermined interim voltage that is less than the reference voltage, the decision-making element generates a control signal that causes the cascaded current source to operate as a non-cascoded current source to ramp down the output voltage of the capacitor from the predetermined interim voltage to the first supply voltage.