# Slobodan Cuk, Laguna Niguel US

## Slobodan Cuk, Laguna Niguel, CA US

Patent application number | Description | Published |
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20090185398 | Integrated magnetics switching converter with zero inductor and output ripple currents and lossless switching - Switching Converter with a novel two-loop Integrated magnetic structure integrates transformer and two output inductors and eliminates large circulating current in the transformer secondary side resulting in ultra high efficiency and zero ripple output current as well as zero ripple currents in both output inductors simultaneously. The novel lossless switching method eliminates the primary side switching losses to result in switching converter with highest efficiency, compact size and additional performance advantages, such as ultra low output ripple voltage, low EMI noise and improved reliability with additional benefits when operated with a front-end Power Factor Converter for computer server applications. | 07-23-2009 |

20100259240 | Bridgeless PFC converter - A truly Bridgeless PFC converter is provided which eliminates the four-diode bridge rectifier and operates directly from the AC line to result in high-efficiency, small size and low cost solution for Power Factor Correction applications. | 10-14-2010 |

20100259241 | Voltage step-down switching DC-to-DC converter - A number of non-isolated and isolated converter embodiments are disclosed all featuring the three switches and characteristic not present in prior-art converters such as: a) reduced voltage stresses on all three switches resulting in safe operation without a danger of voltage overstress of any of the three switches over the full operating range from duty ratio of 0 to 1.0 and thus resulting in wide input voltage operating. b) operating range with magnetics flux and magnetic size much reduced compared to prior-art converters c) stressless switching eliminates switching losses and reduces stresses which are present in prior-art converters. All three features result in simultaneous increase of efficiency, reduction of size and cost when compared with prior-art converters. | 10-14-2010 |

20110057640 | Storageless step-down switching DC-DC converter - A storageless DC-DC converter is provided having simultaneously ultra high efficiency of 99.5% in an ultra compact size leading to 1 kW/inch | 03-10-2011 |

20110169474 | Step-down switching PFC converter - The step-down switching converter is provided, which promises to replace the conventional buck converter in many applications due to its many advantage, such as higher efficiency, smaller size, fast transient response and lower cost among other benefits. | 07-14-2011 |

20110175591 | Step-down low ripple switching converter - The step-down switching converter is provided, which promises to replace the conventional buck converter in many applications due to its many advantage, such as higher efficiency, smaller size, fast transient response and lower cost and ultra low output ripple voltage among other benefits. | 07-21-2011 |

20110285369 | Three-switch step-down converter - A three-switch step-down converter provides efficiency, size, cost and other performance advantages over the conventional two-switch buck converter and other step-down converters, over the entire duty ratio operating range. | 11-24-2011 |

20110292703 | Single-stage AC-to-DC converter with isolation and power factor correction - A new class of Single-Stage AC-DC converters with built-in Isolation and PFC feature is introduced along with the companion hybrid switching conversion method. Several different converter topologies are introduced, which all feature three switches only, single magnetic component and low voltage stresses on all switches. | 12-01-2011 |

20120001612 | Four-switch step-down storageless converter - A four-switch step-down storageless DC-DC converter is provided having simultaneously ultra high efficiency of over 99% in an ultra compact size, while also providing a regulation and maintaining fast transient response while in regulation. Because of its storageless feature it is ideal for demanding computer applications, such as VRM (Voltage Regulator Modules), with extremely fast step-load load current change requirements and tight output voltage regulation requiring ultra low output ripple voltages during the transients. | 01-05-2012 |

20120044722 | ISOLATED SWITCHING CONVERTER - The isolated voltage step-down switching DC-DC converter has one magnetic component, the isolation transformer, and two small size resonant inductors. The transformer is built on a magnetic core with no air-gap, hence no DC storage and thus results in fast load transient response. Two active switches on the primary side have voltage stresses equal to input voltage and two current rectifiers on secondary side have voltage stresses equal to output DC voltage under all operating duty ratio conditions. The converter operates with two independent resonance's, one coinciding with the ON-time interval and the other coinciding with the OFF-time interval resulting in all switches being turned ON and turned OFF at zero current. Primary side high voltage switches operate with zero-voltage switching for all load currents. Despite the two resonance's, the output voltage is controlled by use of the variable duty ratio, constant switching frequency PWM method. | 02-23-2012 |

20120120697 | Three-phase isolated rectifer with power factor correction - A new class of Three-Phase Isolated Rectifiers with Power Factor Correction provides a high efficiency, small size and low cost due to direct conversion from three-phase input voltage to output DC voltage. | 05-17-2012 |

20120249102 | Hybrid-switching Step-down Converter with a Hybrid Transformer - The present invention employs a resonant inductor, a resonant capacitor and a hybrid transformer using a Hybrid-switching method with three switches which results in two distinct switched-networks: one for ON-time interval and another for OFF-time interval. Resonant inductor is placed in series with the hybrid transformer primary to insure the continuity of primary and secondary currents at the switching transitions. The hybrid transformer converts both inductive and capacitive energy storage from the source to the load. The two-phase extension results in tenfold reduction of the output current ripple. | 10-04-2012 |

20120262967 | SINGLE-STAGE INVERTER WITH HIGH FREQUENCY ISOLATION TRANSFORMER - The novel single-stage power processing DC-AC inverter topology with high frequency isolation transformer eliminates the four-transistor unfolding full-bridge stage and provides the output AC voltage at high power conversion efficiency. The new inverter topology has only three switches, two resonant capacitors, a resonant inductor, an output inductor and a small size high-frequency isolation transformer, which does not store the DC energy. The output AC voltage is obtained by the PWM sinusoidal modulation of the duty ratio control of the three switches and can be regulated against the input voltage changes. | 10-18-2012 |

20120268969 | DC-AC INVERTER WITH HIGH FREQUENCY ISOLATION TRANSFORMER - The novel DC-AC inverter topology with high frequency isolation transformer consists of an input DC-DC converter with high frequency isolation transformer and an output full-bridge unfolding converter with four transistors provides the output AC voltage from a DC source. The input DC-DC converter has two primary side controllable switches and a single rectifier on the secondary side, two resonant capacitors, a resonant inductor, an output inductor and a high-frequency isolation transformer, which does not store DC energy. The duty ratio D of the primary side switches is modulated by the rectified AC voltage to result in an output rectified AC voltage, which is unfolded into an AC sinusoidal output voltage by the output full-bridge unfolding converter. | 10-25-2012 |

20120281436 | ISOLATED DC-TO-DC VOLTAGE STEP-UP CONVERTER - An isolated DC-to-DC voltage step-up converter is provided with four switches, an input inductor, an isolation transformer, two resonant inductors and two resonant capacitors and operates with two distinct intervals: ON-time interval and an OFF-time interval. The two half-wave sinusoidal resonant capacitor charge and discharge intervals, one during the ON-time interval and the other during the OFF-time interval are chosen as to eliminate the losses due to energy stored in the leakage inductance of the isolation transformer and to operates with zero voltage switching of the primary side switches. It provides the output voltage regulation over the wide input voltage range with the same low voltage stresses of all four switching devices. The isolation transformer has full bi-directional flux capability and has DC bias. Despite the two independently controlled resonances, the output voltage is controlled by the duty ratio D control at constant switching frequency. | 11-08-2012 |