Abstract: A method for regulating the output voltage of a power supply. A boost PWM switching converter adjusts the gate drive signals to a switching transistor and a pass transistor so that the power supply has an operating frequency, Fs, based on a comparison between a parameter and a reference. The parameter may be a ratio of an input voltage to an output voltage, a difference between the output voltage and the input voltage, or the value of an input voltage. In accordance with the comparison between the parameter and the reference, the switching control circuit linearly decreases the operating frequency of the power supply. By changing the operating frequency, the output and input voltages of the power regulator may be almost equal to each other when operating with a control signal having a low duty cycle while maintaining a low output voltage ripple and a low inductor current ripple.

Abstract: A method for regulating the output voltage of a power supply. A boost PWM switching converter adjusts the gate drive signals to a switching transistor and a pass transistor so that the power supply has an operating frequency, Fs, based on a comparison between a parameter and a reference. The parameter may be a ratio of an input voltage to an output voltage, a difference between the output voltage and the input voltage, or the value of an input voltage. In accordance with the comparison between the parameter and the reference, the switching control circuit linearly decreases the operating frequency of the power supply. By changing the operating frequency, the output and input voltages of the power regulator may be almost equal to each other when operating with a control signal having a low duty cycle while maintaining a low output voltage ripple and a low inductor current ripple.

Abstract: In one embodiment, a power supply controller is configured to operate a plurality of switches in a buck-boost mode to control an output voltage wherein at least one switch of the plurality of switches is enabled for a substantially fixed portion of a cycle of the buck-boost mode.

Abstract: In one embodiment, a power supply controller is configured to operate a plurality of switches in a buck-boost mode to control an output voltage wherein at least one switch of the plurality of switches is enabled for a substantially fixed portion of a cycle of the buck-boost mode.

Abstract: An apparatus for testing the impedance of a medical lead connecting an implantable stimulation device to a nerve or a muscle. The implantable device is of the type comprising a capacitor for stimulating the nerve or the muscle. The system of the invention comprises a current generator for generating a testing current “I” during a calibrated testing pulse and a power circuit coupled to the capacitor and to the current generator for determining if the capacitor is charged by the testing current during the calibrated testing pulse.

Abstract: An apparatus for testing the impedance of a medical lead connecting an implantable stimulation device to a nerve or a muscle. The implantable device is of the type comprising a capacitor for stimulating the nerve or the muscle. The system of the invention comprises a current generator for generating a testing current “I” during a calibrated testing pulse and a power circuit coupled to the capacitor and to the current generator for determining if the capacitor is charged by the testing current during the calibrated testing pulse.