Patent ID: 6603341
Filing Date: 2003-08-05
Classification: H02M,H03K

Abstract:
A load drive circuit comprising:a charge pump circuit for receiving a power voltage from a power source, increasing the power voltage and outputting an output voltage; a low voltage detecting circuit for receiving the output voltage from said charge pump circuit and outputting an output signal to indicate whether the output voltage of the charge pump circuit is in a low voltage state or a high voltage state, wherein said low voltage state is for indicating the output voltage of said charge pump circuit is lower than a predetermined level; and a switch circuit located in a power supply path for connecting said power source and a load for setting said power supply path to an opening state or a closing state based on a drive command signal, the output signal from said low voltage detecting circuit and the output voltage of said charge pump circuit; and wherein when said low voltage detecting circuit detects said low voltage state, said switch circuit sets said power supply path to the opening state irrespective of said drive command signal, and said drive command signal instructs said charge pump circuit to increase said power voltage.