Texas Instruments Corporation

National Semiconductor Corporation

Texas Instruments Incorporated Deutschland, Gmbh

Daniel Ross Herrington

James Harbison Masson

James Michael Patterson

Timothy Roy Sullivan

Vahid Yousefzadeh

Sumeet Prakash Kulkarni

Perry Tsao

Christoph Goeltner

Werner Berns

Joseph V DeNicholas

Michael James Drake

Robert James Divivier

Michael John Shay

William V Miller

Steven Michael Barrow

Kent Bruce Waterson

Alexander Perez

Irwin Nederbragt

Jianhua Helen Pang

David Scott Weinman

Ralph Warren Haines

James Andrew Colgan

Stephen C Pries

Dan Craig O'Neill

John R Gunther

Brian J Marley

Chi Yuen Lai

A light emitting diode system allows for high current end user LED matrix applications while mitigating internal damage to control circuitry that may be caused by excess current flow. In one example, multiple switches operate in parallel across an LED. When an overvoltage condition is detected in a first switch, a logic circuit determines those switches programmed to operate in parallel and causes them to conduct current. This reduces the amount of current flowing through any one switch and mitigates harm to the device. The parallel configuration of switches may be driven by a single pulse width modulated current. This allows the drive current to be divided between parallel transistors, limiting the damaging effects that can be caused by high currents flowing through the transistors.

Overvoltage detection circuit with first and longer second response times

Configurable switch array

A light system (FIG.) is disclosed. The light system includes a plurality of series connected light emitting diodes (-). Each of a plurality of switching devices (-) has a control terminal and each has a current path coupled in parallel with a respective LED. A plurality of fault detector circuits (-) are each coupled in parallel with a respective light emitting diode. Each fault detector circuit has a first comparator (FIG.) arranged to compare a voltage across the respective light emitting diode to a respective first reference voltage (). When a fault is detected, a control signal is applied to the control terminal to turn on a respective switching device of the plurality of switching devices.

LED bypass and control circuit for fault tolerant LED systems

Method and circuits for balancing a first waveform used to drive an LED are disclosed herein. The first waveform has a first cycle with a first amplitude and a second cycle with a second amplitude. An embodiment of the method includes adjusting the first amplitude of the first cycle to match the second amplitude of the second cycle, the result being a second waveform. The LED is driven with the second waveform.

Circuits and methods for reducing flicker in an LED light source

A light system (FIG.) is disclosed. The light system includes a plurality of series connected light emitting diodes (-). Each of a plurality of switching devices (-) has a control terminal and each has a current path coupled in parallel with a respective LED. A plurality of fault detector circuits (-) are each coupled in parallel with a respective light emitting diode. Each fault detector circuit has a first comparator (FIG.) arranged to compare a voltage across the respective light emitting diode to a respective first reference voltage (). When a fault is defected, a control signal is applied to the control terminal to turn on a respective switching device of the plurality of switching devices.

A method includes receiving a sense signal having multiple pulses, where the sense signal is based on an output of a dimmer. The method also includes, for each of multiple sampling periods, sampling a subset of the pulses in the sense signal during that sampling period. The method further includes generating a holding current for the dimmer during the sampling of the subset of pulses in at least one of the sampling periods. In addition, the method includes, for each of the sampling periods, generating an output value identifying a duty cycle for driving one or more light emitting diodes (LEDs). The subset of pulses in each of the sampling periods includes multiple pulses during that sampling period but not one or more initial pulses at a beginning of that sampling period.

Dimmer decoder with improved efficiency for use with LED drivers

An integrated circuit (IC) includes multiple circuits and functions which share multiple internal signal buses, three physical and five logical, according to distributed bus access and control arbitration. The multiple internal signal buses are shared among three tiers of internal circuit functions: a central processing unit and a DMA controller; a DRAM controller and a bus interface unit; and peripheral interface circuits, such as PCMCIA and display controllers. Two of the physical buses correspond to two of the logical buses and are used for communications within the IC. The third physical bus corresponds to three of the logical buses and is used for communications between the IC and circuits external to the IC. Arbitration for accessing and controlling the various signal buses is distributed both within and among the three tiers of internal circuit functions. Maximum performance is thereby achieved from the circuit functions accessed most frequently, while still achieving high performance from those circuit functions accessed less frequently. The IC may provided with a processor core with features that support In-Circuit Emulation (ICE).

Integrated circuit with multiple functions sharing multiple internal

A display protection circuit includes a first OR gate which receives a first pulse at one input and a first clock signal at another input. A second OR gate receives the first pulse at one input and a second clock signal at another input. A first monostable multivibrator is coupled to the first OR gate and receives an output of the first OR gate and generates a second pulse in response thereto. A second monostable multivibrator is coupled to the second OR gate and receives an output of the second OR gate and generates a third pulse in response thereto. A first logic gate is coupled to the first and second monostable multivibrators and generate a fourth pulse which changes state in response to one of the first and second clock signals stopping transitioning for a first predetermined period of time.

Liquid crystal display (LCD) protection circuit

Growing community of inventors

Fort Collins, CO, United States of America

Daniel Ross Herrington