National Semiconductor Corporation

Maxim Integrated Products, Inc.

Linear Technology Corporation

Hendrik Santo

Dimitry Goder

Mansour Izadinia

Thomas Szepesi

The present invention offers a low cost, reliable, on chip implementation that takes advantage of the nature of the average current mode topology to detect phase failures within a multi-phase system. The invention further includes sensing average current to the load, generating error voltages and changing duty cycles when the sensed load current is not at the desired level.

Phase failure detector for multi-phase switching regulators

A switching voltage regulator is described which provides multiple independently regulated outputs. A switch control independently monitors two or more voltage outputs and generates control signals for driving a main switch and two or more auxiliary switches to charge selective ones of the outputs which have fallen below their target voltages. Time sequencing techniques are utilized to control the switching of the auxiliary switches such that energy stored in an inductor is transferred to the appropriate voltage outputs. The switching voltage regulator may be implemented as an integrated circuit and may have various topologies, such as boost, buck, flyback or SEPIC.

Multiple output regulator with time sequencing

Improved controller circuitry for a switching power supply is disclosed. The switching power supply is of the type having a transformer having primary and secondary windings for generating an output voltage at the secondary winding, a power switch for driving the primary winding, and controller circuitry for activating the power switch. The improved controller circuitry includes an oscillator and frequency shift means. The oscillator generates PWM pulses having a predetermined frequency for use in activating the power switch. The frequency shift means gradually shifts the frequency of the PWM pulses at a shift rate in response to the output voltage decreasing to below a threshold level. In another embodiment, a controller for use in a switching power supply includes an oscillator for generating PWM pulses having a predetermined frequency which determine the switching condition of the supply. Frequency shift means is used gradually shifting the frequency of the PWM pulses at a shift rate in response to an output voltage of the switching power supply decreasing to below a threshold level, and programming means is used for programming the shift rate and the threshold level.

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Milpitas, CA, United States of America

Hendrik Santo