A power supply circuit having a standby mode includes an input terminal, an output terminal and a reference terminal. A direct voltage source is connected to the input terminal and the reference terminal and a load is connected to the output terminal and the reference terminal. A series arrangement of an inductive element and a diode are connected to one another at a first node. The inductive element is connected between the input terminal and the first node and the diode is connected between the first node and the output terminal. A first electronic switch has a main current path connected between the first node and the reference terminal. A drive circuit periodically makes the main current path of the first electronic switch conductive and non-conductive. The drive circuit comprises a first switching device for making the main current path of the first electronic switch permanently non-conductive in response to a standby signal (SBS). A second electronic switch has a control electrode and a first and a second main electrode which constitute a main current path connected in parallel with the diode. A second switching device makes the main current path of the second electronic switch permanently conductive in response to the standby signal. In the standby mode the second electronic switch short-circuits the diode whereby more voltage is available at the output terminal.
A DC/DC converter for supplying a plurality of direct-current output voltages using a single pulse-width-modulator. A voltage regulator in the DC/DC converter comprises first and second switch elements, a pulse width modulator for generating a switching signal to control the switching of the first switch element, an inductor the generation and the collapse of the magnetic field thereof being controlled by selective conduction of the first switch element, and a capacitor charged with current supplied in response to the collapse of the magnetic field of the inductor as conducted thereto by selective conduction of the second switch element. The level of output voltage from the voltage regulator means is sensed to generate a control voltage, applied through output feedback circuitry for cutting off the generation and the collapse of the magnetic field of said inductor responsive to the control signal indicating that the level of the output voltage exceeds a prescribed value, thus to regulate the amount of charge supplied to the capacitor in response to the switching signal generated by the pulse width modulator. The output feedback circuitry includes first and second transistors that are connected by Darlington method with a base electrode of the first transistor having an emitter electrode of the second transistor connected thereto, with a base electrode of the second transistor connected to receive the control voltage, with an emitter electrode of the first transistor connected to receive the switching signal generated by the pulse width modulator, and with an interconnection of the collector electrodes of the first and second transistors connected to the first switch element for controlling the selective conduction thereof.
The present invention relates to a linear regulator of a voltage for supplying a load, including circuitry for setting to partial stand-by the regulator as a response to a control signal supplied by the load setting of a linear regulator to stand-by the regulator in response to a control signal supplied by the load.
A computer processor includes a plurality of storage elements, such as logic gates and flip-flops, that are interconnected in a first configuration during normal operation of the processor. A plurality of selector elements connected to the storage elements are used to rearrange the storage elements into a second configuration upon entry into a low-power mode of operation. In general, the storage elements, when rearranged into the second configuration, form a chain through which data passes serially for storage in a storage device, such as a memory device or a hard drive.
A simple, self-oscillating, DC-to-DC converter current source, using a small number of simple components, with hysteresis around the current switching thresholds. Slight design modifications allow operation in any of several topologies. In another aspect of the invention, operation as a regulated DC-to-DC converter voltage source is achieved through the addition of a small number of additional components, with slight design modifications allowing operation in any of several topologies.
