Patents

• “High Efficiency Power Factor Corrected Power Converters”, US Patent 11,626,795  This invention reveals power factor correction circuits that achieve much higher efficiency and power density using a topology that achieves soft switching and dramatically reduces the amount of power processed and the number of circuit elements in the main power path. The circuit achieves very high power factor (>0.99) and very tight load regulation, i.e., no line frequency ripple. A novel auxiliary circuit that processes a small fraction of the load power is the key to the exceptional performance. (34)  https://patents.google.com/patent/US11626795

A single stage power factor correction system with smaller size, lower cost, lower power losses, lower processed power and both highly precise near unity power factor and highly precise load regulation free of all line frequency ripple. US11,626,795

 

• “Zero Voltage Switching Flying Capacitor Power Converters”, US Patent 11,515,789 This patent describes methods to eliminate switching losses in flying capacitor networks.(33)  https://patents.google.com/patent/US11515789

Techniques for achieving zero voltage turn on switching thereby eliminating the majority of switching power losses and enabling higher frequency operation are described in this patent. US11,515,789

 

• “Small Form Factor Power Conversion System”, US Patent 11,211,724  This patent describes a very low profile power conversion system. (32)  https://patents.google.com/patent/US11211724

• “Multi-phase Hysteretic Power Converters”, Application Number 61/569,433  A control scheme for fast load transient hysteretic converters that requires no loop feedback and control circuits and methods for accomplishing precise frequency and phase control of hysteretic converters for multi-phase control. This application and several that follow were abandoned by the assignee, ASIC Advantage, after its purchase by MicroSemi in 2011.  These published applications are free to use if not revealed by other patent applications with earlier application dates.

• “Bridgeless Coupled Inductor Boost Power Factor Rectifiers”, Application Number 61/376,178  A zero voltage switching coupled inductor boost power factor rectifier which eliminates the line bridge rectifier, thereby reducing conduction losses.

• “Auto-Optimization Circuits and Methods for Cyclical Electronic Systems”, Application Number 61/370,444  Circuits and methods for optimizing switch timing for zero voltage switching power converters and synchronous rectifiers.

• “Multiple Independently Regulated Parameters Using a Single Magnetic Circuit Element”, Application Number 61/231,116  Control schemes for converters with multiple independently regulated outputs plus power factor correction requiring only a single magnetic core.

• “Zero Voltage Switching Boundary Mode Coupled Inductor Boost Power Converters”, Application Number 61/221,049  A zero voltage switching low conduction loss approach to low power PFC converters.

• “Boundary Mode Coupled Inductor Boost Power Converters”, Application Number 61/221,050  A lower conduction loss approach to PFC converters using a control scheme that eliminates reverse recovery losses.

• “Power Converter Circuits Having Bipolar Outputs and Bipolar Inputs”, US Patent 7,944,188  A bridgeless PFC scheme that solves the problem of common mode noise characteristic of many bridgeless PFC circuits. (31)  https://patents.google.com/patent/US7944188

• “Integrated Multitransformer”, U.S. Patent 7,956,491  A novel method of combining multiple independent transformers on a single core. (30)  https://patents.google.com/patent/US7956491

A technique for using outer leg windings of a power transformer to pass signals across the isolation boundary independently of the power transformer for system control is revealed. US7,956,491

 

• “Zero Voltage Switching Coupled Inductor Boost Power Converters”, U.S. Patent 7,864,549  Continuation in part of U.S. Patent 7,551,459. (29)  https://patents.google.com/patent/US7864549

A coupled inductor boost converter which eliminates turn on switching power losses and provides EMC and transformer utilization advantages over all other simple isolated circuit topologies is revealed. US7,864,549

 

• “Adaptive Switch Timing Circuits for Zero Voltage Switching Power Converters”, U.S. Patent 7,714,548  Reveals adaptive switch timing circuits that enable optimal switch timing for maximum efficiency in zero voltage switching circuits. (28)  https://patents.google.com/patent/US7714548

Optimal switch timing for the three different energy sufficiency conditions. US7,714,548

 

Circuits that accommodate all three energy sufficiency conditions for achieving optimal adaptive switch timing for zero voltage switching power converters are revealed. US7,714,548

 

• “Zero Voltage Turn Off Transition Gate Driver Circuit and Method”, serial number 60/970,748  Reveals circuits and methods of achieving zero voltage turn off transition switching, including high peak current gate drive turn off drivers integrated with power MOSFETs for low or zero loss turn off transition switching.

• “Multiple Inductor Integrated Magnetic Circuit Elements”, serial numbers 60/941,274 and 60/970,249  Reveals methods of accomplishing multiple independent inductors on a common core and methods to accomplish enhancing leakage inductance and eliminate winding eddy current losses due to fringing flux.

• “Self Limiting Zero Voltage Switching Power Conversion Networks”, U. S. Patent 7,649,754  Reveals a family of non-isolated zero voltage switching power conversion networks with inherent over load protection and with the ability to easily achieve zero voltage switching over a broad range of line and load voltages. (27)  https://patents.google.com/patent/US7649754

• “Uncoupled and Loosely Coupled Integrated Magnetic Circuit Elements”, serial number 60/744,823  Reveals some new integrated magnetic circuit element structures for combining multiple independent magnetic circuit elements on a common core and new magnetic structures that seek to enhance leakage inductance. Some of the structures also seek to eliminate fringing flux and its associated eddy current power losses.

• “Zero Voltage Switching Coupled Inductor Boost Power Converters”, U.S Patents 7,551,459  A new simple low parts count isolated coupled inductor power converter which achieves low emi and high efficiency for moderate and high output voltage applications is revealed. (26)  https://patents.google.com/patent/US7551459

• “Tapped Inductor Power Conversion Networks”, US Patent Number 7,480,156  New non-isolated tapped inductor power conversion networks for a variety of applications having lower component stresses and higher efficiency than previously known tapped inductor networks is revealed. Included in this application are both hard and soft switching versions of the minimum voltage tapped inductor buck converter. (25)  https://patents.google.com/patent/US7480156

Tapped inductor power converters are revealed with reduced component stresses compared to prior art tapped inductor power converters. Other new converters revealed include members of the SEPIC family. US7,480,156

 

• “Fully Clamped Coupled Magnetic Circuit Elements in Power Conversion Circuits”, U.S. Patent 7,606,051  A widely applicable circuit technique for improving power conversion circuits which eliminates EMI and reduces the number of required magnetic circuit elements is revealed. A simple integrated magnetic circuit element for ZVS converters that can be used with the new circuit technique is also revealed. (24)  https://patents.google.com/patent/US7606051

Fully clamped circuit structures for simultaneously reducing both EMI and switching power losses are revealed. US7,606,051

 

• “Synchronous Rectifier Control Circuits” published application number 11/379,820  Circuits for optimal timing of high frequency synchronous rectifiers are revealed.

• “Capacitively Coupled High Side Gate Driver”, U.S. Patent Number 7,589,571  A simple, inexpensive, but effective high side gate driver circuit for active clamp converters and half bridges which uses neither level shifting circuits nor magnetics. (23)  https://patents.google.com/patent/US7589571

A fast gate drive circuit for a high side switch or floating switch accomplished with simple logic gates and a low side driver integrated circuit. No conventional level shifting circuit is required. US7,589,571

 

• “Secondary Side Post Regulators”, U.S. Patent Number 7,439,717  A synchronously switched buck post regulator for forward converters. (22)  https://patents.google.com/patent/US7439717

Secondary side post regulators for forward converters are revealed with reduced total magnetic core volume. US7,439,717

 

• “Synchronous rectifier gate drive circuits for zero voltage switching power converters”, U.S. Patent Number 6,856,522  Practical circuits that improve prior art circuits that rely on a small choke for driving a ZVS turn on transition of a main switch for providing drive energy and timing for a synchronous rectifier at the same time. (21)  https://patents.google.com/patent/US6856522

• “Floating Gate Drive Circuits”, U.S. Patent Number 7,466,168  Gate drive circuits for improving and optimizing the performance of ZVS power converters are revealed. (20)  https://patents.google.com/patent/US7466168

A boot strap powered gate drive circuit for a switch having a floating reference voltage between two DC voltages neither of which are ground, such as a tapped inductor buck converter as shown here. US7,466,168

 

• “Adaptive gate drivers for Zero Voltage Switching Power Conversion Circuits”, US Patent 6,580,255  Adaptive gate drivers that optimize the switch timing for both energy sufficient and energy insufficient turn on transitions is revealed, also a circuit that limits the gate drive charge and energy and provides protection from gate over voltage is revealed. (19)  https://patents.google.com/patent/US6580255

A simple adaptive gate drive circuit for a ZVS converter that facilitates optimal turn on timing. US6,580,255

 

• “Synchronous Rectifier Self Gate Drive for Zero Voltage Switching Power Conversion Circuits”, U.S. Patent Number 6,650,550  A simple synchronous rectifier self gate drive mechanism that relies upon the voltage generated by a small magnetic circuit element already contained in many zero voltage switching cells is revealed. (18)  https://patents.google.com/patent/US6650550

• “Circuits and Circuit Elements for High Efficiency Power Conversion”, U.S. Patent Number 6,822,427  New ZVS switching cells are revealed. (17)  https://patents.google.com/patent/US6822427

• “Zero Voltage Switching Power Conversion Circuits”, US Patent 6,462,963  A ZVS switching cell that contains an integral input and output filter, using a single small magnetic that also serves as the ZVS drive mechanism, to force both the input and output current to be continuous in a tapped inductor buck converter is revealed. Also revealed is a resistorless current sensing mechanism for ZVS converters. (16)  https://patents.google.com/patent/US6462963

• “Composite MOSFET Cascode Switches for Power Converters”, US Patent 6,483,369  A composite switch for fast switching and elimination of most gate drive losses which enables the use of larger amounts of silicon without a gate drive loss or speed penalty.(15)  https://patents.google.com/patent/US6483369

A composite cascode switch wherein a small die low voltage low on resistance switch is used to control the on/off state of a high voltage large die switch by controlling the current in the source circuit of the high voltage switch. This arrangement has become very popular for wide band gap semiconductors and is now commonly known as “source switching”. US6,483,369

 

• “Zero Voltage Switching Cells for Power Converters”, US Patent 6,452,814  Two universally applicable zero voltage switching cells are revealed, both cells require two active switches, a capacitor, and a small magnetic circuit element, one cell incorporates an integral input filter, the other cell can be accomplished with two low side N channel FETs. The second cell yields cost and space improvements and simplification in the popular zero voltage active clamp flyback converter of US Patent 5,402,329 (above), as just one example. The second cell when applied to a boost converter yields a simple high efficiency ZVS PFC circuit. (14)  https://patents.google.com/patent/US6452814

Several zero voltage switching cells have been invented at Power Electronics Innovations Laboratory for which patents have been issued. In this one a switching cell replaces a main switch in a hard switching circuit to yield a similar circuit with identical properties and also zero voltage switching thereby largely eliminating power circuit switching losses and enabling higher frequency operation and smaller capacitor and magnetic elements without incurring higher switching losses. US 6,452,814

 

• “Synthesis Methods for Enhancing Electromagnetic Compatibility and AC Performance of Power Conversion Circuits”, US Patent 6,507,176  Methodologies for transforming prior art power conversion networks into new networks with improved terminal current properties, improved common mode performance, and improved bandwidth and transient response performance are revealed. (13)  https://patents.google.com/patent/US6507176

The synthesis method shown in the figure illustrates how a three terminal network such as a buck converter can be changed from a converter having pulsating terminal currents and a high level of displacement currents to a converter with non-pulsating terminal currents with a high degree of ripple cancellation and a first order cancellation of displacement currents for dramatically improved noise properties. US6,507,176

 

Shown is a boost converter having both non-pulsating input and output currents. This patent and several others that followed revealed many converters, both non-isolated and isolated, with inherently improved EMC performance including some with both reduced ripple current and much reduced displacement current achieving both much better differential mode noise performance and much better common mode noise performance and some with ripple current cancellation. The last of these patents revealed circuit synthesis methods for creating new topologies with much improved EMC characteristics from well known circuits having poor EMC characteristics. US6,252,383, US6,304,065, US6,437,999, US6,507,176

 

• “Power Electronic Circuits With Ripple Current Cancellation”, U.S. Patent 6,437,999  This patent outlines a methodology for transforming three terminal networks with some or all terminals pulsating to forms with all terminals zero ripple. In most cases the magnetics requirements are a single simple core such as a toroid or E core of approximately the same size as the unaltered three terminal network. Included are buck, boost, flyback, SEPIC, and four quadrant three terminal networks using a single simple core with two switches and zero ripple at all three terminals. Also included are ZVS zero ripple tapped inductor, zero ripple quadrature, and active reset ZVS flyback, forward, and interleaved coupled inductor buck converters with zero input current ripple. (12)  https://patents.google.com/patent/US6437999

• “Power Electronic Circuits With All Terminal Currents Non-Pulsating”, U.S. Patent 6,304,065  This patent outlines a methodology for transforming almost any converter that can be reduced to a three terminal network from a form with some terminal currents pulsating to a form with all terminal currents non-pulsating. The patent describes the transformation of buck, boost, flyback, SEPIC, four quadrant, and quadrature converters to non-pulsating forms. All of these converter forms use a single magnetic of approximately the same size as the unaltered converter except for the quadrature forms which require two magnetic elements of approximately the same size as the unaltered converter. (11)  https://patents.google.com/patent/US6304065

• “A Universal Zero Voltage Transition Switching Cell”, U.S. Patent 6,411,153  A generic two terminal switching cell that, when substituted for the main switch in a PWM converter, renders the new converter soft switching without changing the other properties of the converter. (10)  https://patents.google.com/patent/US6411153

• “Buck and Boost Power Converters with Non-Pulsating Input and Output Terminal Currents”, U.S. Patent 6,252,383  Improved buck and boost power converters using a single simple magnetic circuit element and two switches. (9)  https://patents.google.com/patent/US6252383

• “Self Clamping Zero Voltage Switching DC Transformers”, U.S. Patent Number 6,195,270  Reveals high efficiency DC transformer circuits suitable for high switching frequency, high power density, and synchronous rectifier self drive. (8)  https://patents.google.com/patent/US6195270

• “Zero Voltage Switching Active Reset Power Converters”, U.S. Patent Number 6,198,260  This is a generalized switching cell that achieves zero voltage switching for a wide variety of non-isolated and isolated power converters. ZVS versions of buck, boost, buck boost, Cuk, SEPIC converters, etc. are formed from basic hard switching converters using the generalized switching cell. (7)  https://patents.google.com/patent/US6198260

• “High Efficiency Soft Switching Coupled Inductor Power Converters”, U.S. Patent 6,272,023  This is a continuation of the next item below but with a different ZVS drive mechanism. (6)  https://patents.google.com/patent/US6272023

This circuit provides zero voltage switching in an alternate arrangement of a forward converter. One variation of this circuit provides ripple current cancellation at nominal line voltage with a single ended forward converter transfer function. US6,272,023

 

• “Efficient Power Converter Having Zero Voltage Switching”, U.S. Patent Number 6,560,127  Full bridge forward converter which harnesses the stored energy in the output choke(s) to drive the resonant transitions. ZVS is accomplished without reversing the choke current. (5) https://patents.google.com/patent/US6560127

• “Dual Opposed Interleaved Coupled Inductor Soft Switching Converters”, U.S. Patent Number 6,147,886  This is a family of soft switching converters. One member of this family achieves zero output ripple at nominal line, synchronous rectifier self drive, and has load invariant ZVS drive energy, i.e., same drive energy available at no load and full load, another member is a low parts ZVS full bridge, high power, forward transfer function converter with lower conduction losses and higher packaging density than the standard ZVS full bridge forward converter and which eliminates staircase saturation. (4)  https://patents.google.com/patent/US6147886

• “Regulated Input Current Regulated Output Voltage Power Converter”, U.S. Patent Number 6,101,108  An efficient two stage power factor control scheme. (3)  https://patents.google.com/patent/US6101108

This patent reveals a non-isolated PFC power converter with both tightly regulated line current and tightly regulated load voltage with reduced power processing. US6,101,108

 

• “Planar Stacked Layer Inductors and Transformers”, US Patent Number 6,114,939  This patent describes a magnetic element structure that largely eliminates the proximity effect losses common to spiral wound planar magnetics. (2)  https://patents.google.com/patent/US6114939

This patent reveals a four layer planar magnetic circuit element structure wherein copper winding layers are interleaved vertically with layers of ferromagnetic material. US6,114,939

 

• “Zero Voltage Switching Pulse Width Modulated Power Converters”, U.S. Patent Number 5,402,329  This patent contains a family of converters including a ZVS coupled inductor buck converter and the commercially viable (several companies are using these circuits in high volume products) version of the ZVS Active Clamp Flyback Converter which is a low parts count resonant transition converter that achieves zero voltage switching for all switches for all transitions as well as elimination of rectifier reverse recovery effects. (1)  https://patents.google.com/patent/US5402329

This patent describes flyback and coupled inductor buck converters operating at fixed frequency that achieve zero voltage switching over the full operating range without the requirement that the magnetizing current be reversed thereby eliminating the conduction loss penalty of prior art zero voltage switching flyback converters. Shown is the coupled inductor buck embodiment of the invention. US5,402,329