Eric A King

US Patent:

8212493, Jul 3, 2012

Filed:

Jun 30, 2009

Appl. No.:

12/495720

Inventors:

John L. Melanson - Austin TX, US
Mauro L. Gaetano - Austin TX, US
Eric King - Dripping Springs TX, US
Robert Grisamore - Austin TX, US
Zhaohui He - Austin TX, US

Assignee:

Cirrus Logic, Inc. - Austin TX

International Classification:

H05B 41/36
H02M 3/335

US Classification:

315247, 363 16

Abstract:

A cascaded power converter having an auxiliary power supply operated from the second switching power stage provides efficient operation by activating the auxiliary power supply early in the startup process. A low energy transfer operating mode is initiated in the second switching power stage to charge the auxiliary power supply output without generating significant disruption at the load. After the first switching power stage is started and the intermediate node voltage has increased to a level sufficient to operate the second switching power stage, the final switching power stage enters a normal operating mode. The low energy transfer operating mode has a substantially reduced switching rate and pulse width from that of the normal operating mode.

US Patent:

8536799, Sep 17, 2013

Filed:

Mar 31, 2011

Appl. No.:

13/077483

Inventors:

Robert T. Grisamore - Austin TX, US
Firas S. Azrai - Austin TX, US
Mohit Sood - Austin TX, US
John L. Melanson - Austin TX, US
Eric J. King - Dripping Springs TX, US
Jean-Charles Pina - Austin TX, US

Assignee:

Cirrus Logic, Inc. - Austin TX

International Classification:

H05B 37/02

US Classification:

315294, 315185 R, 315200 R, 315291

Abstract:

In at least one embodiment, a lighting system receives an input signal, such as a supply voltage, that can be affected by a dimmer. The supply voltage can be affected by a dimmer when, for example, a dimmer phase cut (i. e. chopped) the supply voltage. A dimmer detection system of the lighting system determines if a dimmer is affecting the supply voltage. In at least one embodiment, the dimmer detection system also determines a type of the dimmer, such as detecting if the dimmer is a leading edge or trailing edge dimmer. In at least one embodiment, the dimmer detection system provides dimmer type data to one or more other circuits such as a switching power converter controller. The one or more other circuits utilize the dimmer type data to affect their operation.

US Patent:

8547034, Oct 1, 2013

Filed:

Nov 16, 2011

Appl. No.:

13/298002

Inventors:

John L. Melanson - Austin TX, US
Eric J. King - Dripping Springs TX, US

Assignee:

Cirrus Logic, Inc. - Austin TX

International Classification:

H05B 37/02

US Classification:

315247, 315224, 315291

Abstract:

In at least one embodiment, an electronic system includes a controller, and the controller provides compatibility between an electronic light source and a trailing edge dimmer. In at least one embodiment, the controller is capable of predicting an estimated occurrence of a trailing edge of a phase cut AC voltage and accelerating a transition of the phase cut AC voltage from the trailing edge to a predetermined voltage threshold. In at least one embodiment, the controller predicts an estimated occurrence of the trailing edge of the phase cut AC voltage on the basis of actual observations from one or more previous cycles of the phase cut AC voltage.

US Patent:

8610364, Dec 17, 2013

Filed:

Jul 29, 2011

Appl. No.:

13/194808

Inventors:

John L. Melanson - Austin TX, US
Eric J. King - Dripping Springs TX, US

Assignee:

Cirrus Logic, Inc. - Austin TX

International Classification:

H05B 37/00
H05B 37/02

US Classification:

315200R, 315224

Abstract:

A system and method includes a controller that is configured to coordinate (i) a low impedance path for a dimmer current, (ii), control of switch mode power conversion and (iii) an inactive state to, for example, to allow a dimmer to function normally from cycle to cycle of an alternating current (AC) supply voltage. In at least one embodiment, the dimmer functions normally when the dimmer conducts at a correct phase angle indicated by a dimmer input setting and avoids prematurely resetting while conducting. In at least one embodiment, by coordinating functions (i), (ii), and (iii), the controller controls a power converter system that is compatible with a triac-based dimmer. In at least one embodiment, the controller coordinates functions (i), (ii), and (iii) in response to a particular dimming level indicated by a phase cut, rectified input voltage supplied to the power converter system.

US Patent:

8207788, Jun 26, 2012

Filed:

Apr 7, 2008

Appl. No.:

12/082081

Inventors:

Wai L. Lee - Austin TX, US
Patrick A. Quinn - Beaverton OR, US
Garry N. Link - Pacific City OR, US
Adam C. Broun - Portland OR, US
Eric T. King - San Jose CA, US

Assignee:

Avnera Corporation - Beaverton OR

International Classification:

H03F 3/217

US Classification:

330251

Abstract:

A differential feedback amplifier is provided with a feedback network wherein that feedback network is adjustable so as to improve the PSRR of the amplifier. In another aspect of the present invention, a differential feedback amplifier is provided with a feedback network wherein that feedback network is adjustable so as to improve the CMRR of the amplifier. In a further aspect of the present invention, a Class D amplifier is provided with a passive differential feedback, summing with an input current at a differential virtual ground produced by an amplifier which is a sub-section of the Class D amplifier.

US Patent:

20100117450, May 13, 2010

Filed:

Sep 4, 2009

Appl. No.:

12/554262

Inventors:

Firas Azrai - Austin TX, US
Arthur T. Kimmel - Dallas TX, US
Eric J. King - Dripping Springs TX, US
Eric B. Smith - Austin TX, US
Michael E. Yates - Austin TX, US

International Classification:

H02M 3/335

US Classification:

307 31

Abstract:

A voltage converter includes a plurality of power conversion circuits that receive respective digital control inputs and supply respective output signals that are separately programmable to have respective desired voltages. A control circuit, a portion of which is shared by the power conversion circuits on a time multiplexed basis, supplies the digital control inputs. The shared portion of the control circuit includes, a first selector circuit to select on the time multiplexed basis set points for respective ones of the output signals; a digital-to-analog converter to convert a selected set point to an analog set point signal, a second selector circuit to select one of measured signals that correspond to respective ones of the set points, and a summer coupled to determine a difference between the analog set point signal and a corresponding measured signal and generate an error signal indicative thereof

US Patent:

20120025608, Feb 2, 2012

Filed:

Mar 31, 2011

Appl. No.:

13/077421

Inventors:

John L. Melanson - Austin TX, US
Eric J. King - Dripping Springs TX, US

International Classification:

H02J 4/00

US Classification:

307 24, 307 43

Abstract:

An electronic system includes two power supplies to supply an operating voltage to a switching power converter. The first power supply, referred to as a start-up power supply, includes a first source follower transistor to conduct a start-up current for a controller and supply an operating voltage for the controller. The controller controls operation of the switching power converter. A second power supply, referred to as an auxiliary power supply, includes a second source follower transistor to conduct a steady-state operational current for the controller and supply an operating voltage for the controller. In at least one embodiment, once the second power supply begins supplying the operating voltage to the controller, the start-up power supply automatically ceases supplying the start-up current to the controller.

US Patent:

20120025729, Feb 2, 2012

Filed:

Jul 29, 2011

Appl. No.:

13/194531

Inventors:

John L. Melanson - Austin TX, US
Eric King - Dripping Springs TX, US

International Classification:

H05B 37/02

US Classification:

315224

Abstract:

A circuit for powering high-efficiency lighting devices from a thyristor-controlled dimmer predicts a zero-crossing time of the AC power line supplying the dimmer and causes a glue impedance to be imposed at the output of the dimmer starting at the time of the zero-crossing, so that the timer in the dimmer will operate properly to generate the turn-on event at the correct time. At turn-on, a lower level of impedance is presented to absorb the energy associated with the turn-on event. A higher level of impedance may be presented after the energy is absorbed until all of the energy needed for the cycle is transferred. Then, a high impedance state is maintained until the next zero-crossing time. The impedance control may be provided by non-uniform operation of a power converter that supplies the lighting devices, or by a combination of non-uniform power converter operation and dissipative loading.