Maxim Integrated Products, Inc.

Kinetic Technologies International Holdings LP

Kinetic Technologies

Semtech Corporation

Karl Richard Volk

Sofjan Goenawan

Brian Ben North

Brett A Miwa

Jan Nilsson

Jason Allen Wortham

Gary Michael Hurtz

Russell Deans

Thomas Joseph Karpus

David Paul Keesor

Paul Edward Hinson

Jeffrey Lewis Amram Summit

Andrew J Mrizek

Voltage regulator circuits and methods therefor provided. In some embodiments, a voltage regulator circuit comprises: a first switch coupled to a power input; a second switch coupled to the first switch; a switching node between the first switch and the second switch; an inductor coupled between the switching node and an output node; a capacitor coupled between the output node and ground; a driver configured to operate the first and second switches according to a pulse-width-modulated (PWM) signal; a PWM circuit configured to generate the PWM signal based on at least an error signal; and a phase detector configured to generate the error signal based on a phase difference between the PWM signal and a clock reference signal.

Adaptive on-time DC-to-DC buck regulators with constant switching frequency

Adaptive on-time switching voltage regulator circuits and methods therefor provided. In some embodiments, a voltage regulator comprises: a switching circuit configured to generate a switching signal at a switching node according to a pulse-width modulated (PWM) signal; a phase-lock loop (PLL) configured to lock the PWM signal to a clock reference signal, the PLL comprising: a PWM signal generator configured to generate the PWM signal according to an error signal, and a phase detector configured to generate the error signal based on the PWM signal and the clock reference signal.

Switching voltage regulators with phase-lock loops and lock range extension

A system includes an inductor having first and second terminals. First and second transistors have first terminals connected to the first and second terminals of the inductor, respectively, and second terminals connected to a power supply and a common potential, respectively. Third and fourth transistors have first terminals connected to the first and second terminals of the inductor, respectively, and second terminals providing first and second output voltages of first and second polarities, respectively. First and second feedback circuits generate first and second feedback signals based on the first and second output voltages, respectively. A first control circuit controls the first and third transistors based on the second feedback signal and not based on the first feedback signal. A second control circuit controls the second and fourth transistors based on the first feedback signal and not based on the second feedback signal.

Single-input multiple-output inverting and non-inverting buck/boost switching regulator control method and apparatus

Various embodiments of the invention allow for active AC ripple noise cancellation. In certain embodiments, noise cancellation is accomplished by modulating an LED driver output in a polarity opposite to the ripple, thereby, preventing interference with ripple-sensitive loads. Certain embodiments take advantage of a filter network to prevent the LED driver from modulating LED current in response to ripple that falls within a visible frequency range so as to prevent flicker in an LED backlight display. In addition to protecting ripple-sensitive loads from large ripple currents, efficiency is increased by reducing both I&#xb7;R losses and peak currents, thereby, extending the useful battery life time in mobile devices.

Method and apparatus for active ripple cancelation

A system and method is provided for preventing a dropout of an LED current. In one embodiment of the present invention, the system includes a voltage source, a first circuit, a second circuit, a controller, and at least one LED. The first circuit receives a reference voltage from the voltage source, receives set-point current data from the controller, and uses the reference voltage and the set-point current data to produce a threshold voltage. The threshold voltage is then provided to the second circuit, where it is converted into an output current, which is drawn through the LED. The second circuit then compares the threshold voltage to an output voltage corresponding to the output current, and provides an output to the controller. The controller then uses the output to determine whether a dropout has occurred. If a dropout has occurred, then second set-point current data is provided to the first circuit.

Automatic dropout prevention in LED drivers

A step-up/step-down switching regulator control method for a regulator having an inductor with first and second leads, a first switch for controllably coupling the first lead to a source of power, a first device between the first lead and a circuit ground, a second switch for controllably coupling the second lead to the circuit ground, and a second device between the second lead and a regulator, the method comprising operating the switches in a sequence of phases when the source of power has a voltage exceeding the regulator output and in the same sequence of phases when the source of power has a voltage less than the regulator output, the phases being phasewith the first and second switches closed, phasewith the first switch closed and the second switch open, and phasewith both switches open. The first and second devices may be switches or diodes. Various embodiments are disclosed.

Step-up/step-down (buck/boost) switching regulator control methods

Current source methods and apparatus for light emitting diodes providing constant diode current and illumination in the presence of voltage and process variations. The method comprises providing a predetermined current through a first transistor, and mirroring the current through the first transistor to at least one additional transistor while holding the voltage across the first transistor to a predetermined value, wherein each additional transistor is coupled in series with a light emitting diode. An exemplary circuit, as well as various illustrative applications are disclosed.

Current source methods and apparatus for light emitting diodes

Step-up/step-down switching regulators and pulse width modulation control therefor which can provide a high output current, high efficiency, use physically smaller inductor and transistors, have lower output voltage ripple, excellent line and load regulation stability and very fast transient response. The modulation control includes three operating states. The improved operating characteristics are obtained by including, as one of the operating states, the direct flow of current from the input of the regulator to the output of the regulator. This allows delivery of current from the inductor to the output a greater percentage of the time than in the prior art. An exemplary embodiment and exemplary method of operation are described.

Growing community of inventors

Scotts Valley, CA, United States of America

Karl Richard Volk