Patent ID: 6828766
Filing Date: 2004-12-07
Classification: H02M,Y02B

Abstract:
A regulator of the supply voltage for a load comprising:a supply node at an unregulated voltage; a ground node; an output node providing an output voltage; a power stage, connected between the supply node and the ground node, and including at least one power switch; an inductor driven by the power stage, and connected by the power switch to the supply node; an output capacitor connected between the output node and the ground node and having a parasitic series resistance; a first comparator with hysteresis producing a stand-by signal when the output voltage exceeds a reference voltage; an integrator, the power consumption of which may be reduced by the stand-by signal, including a capacitive integration branch, and generating a feedback signal representing a programmed output current; a clamp connected in parallel to the capacitive integration branch for making the feedback signal greater than a minimum threshold corresponding to a minimum programmed output current; a first current sensing circuit to generate a first signal proportional to current in the inductor; a second comparator disabled by the stand-by signal, receiving the feedback signal and the first signal, and producing a logic comparison signal; a controller to control the at least one power switch of the power stage, receiving the logic comparison signal and the stand-by signal; and a second current sensing circuit to sense current in the clamp and generate a second signal representative of the sensed current; the first comparator receiving the second signal to enable the stand-by signal when the current in the clamp exceeds an upper threshold and disable the stand-by signal when the current in the clamp drops below a lower threshold.