Monolithic Power Systems, Inc.

Harman International Industries, Inc.

Zheng Luo

Yu-Huei Lee

Junjian Zhao

Tong Chen

Chia-Lung Ni

Huan Liu

Eric X Yang

Chao Liu

Yuancheng Ren

Kaiwei Yao

Qingshan Zhang

Michael Ren Hsing

Yiqing Jin

Ze-Qiang Yao

Heng Li

Liwei Hou

Suwei Wang

Liyun Lv

Ken Yi

LED driving circuit includes a first current source, a second current source, a current sensing circuit, and a control circuit. The first current source, coupled in series with a heat dissipation resistor, provides a first current path to the LED string. The second current source, coupled in parallel with the serially coupled first current source and the heat dissipation resistor, provides a second current path to the LED string. The current sensing circuit is configured to sense a current sense signal representing a current flowing through the LED string. The control circuit is configured to control a current distribution of the first current path and a second current path in response to the current sense signal. When the current sense signal is greater than a threshold, a current flowing through the first current path is larger than a current flowing through the second current path.

LED driving circuit and method for controlling a current distribution to an LED string

A LED driving system for driving a LED matrix. The LED driving system includes an interconnection structure having a first surface and a second surface opposite to the first surface and a plurality of driver dies/chips attached to the first surface of the interconnection structure. The LED matrix is divided into a plurality of sub LED matrix sections that are attached to the second surface of the interconnection structure. The interconnection structure is configured to electrically couple each one of the plurality of sub LED matrix sections to a corresponding one driver die/chip in the plurality of driver dies/chips.

LED matrix driving system

An LED driving system for synchronizing two LED driving integrated circuits to drive LED strings. The LED driving system sequentially activates the LED strings driven by the first LED driving integrated circuit and then outputs a downstream enabling signal from the first LED driving integrated circuit to the second LED driving integrated circuit to activate the LED strings driven by the second LED driving integrated circuit.

Led driving system with communication between multiple integrated circuits

A feedback control circuit in an LED driving circuit for driving a plurality of LED strings. Each LED string provides a headroom detecting voltage. The feedback control circuit has a status detecting circuit, a counting circuit and a modulating circuit. The status detecting circuit compares each headroom detecting voltage with a low headroom threshold voltage and a high headroom threshold voltage and generates an up self-status signal and a down self-status signal. The counting circuit counts or keeps unchanged and then generates a counting signal based on the up self-status signal and the down self-status signal. The modulating circuit generates a modulating signal based on the counting signal. And based on the modulating signal, the feedback control circuit generates a feedback control signal to regulate a bias voltage supplying the plurality of LED strings.

Adaptive feedback control in LED driving circuits

An LED driving system with a master-slave architecture. The LED driving system has at least two LED driving circuits which both have a first status detecting circuit, a second status detecting circuit and a first feedback control circuit. The first status detecting circuit receives a plurality of headroom detecting voltages provided by a plurality of LED strings and generates at least one self-status signal. The second status detecting circuit receives a downstream feedback signal and generates at least one downstream status signal. The first feedback control circuit generates a first feedback control signal based on the at least one self-status signal and the at least one downstream status signal. The second status detecting circuit of one LED driving circuit is coupled to the first feedback control circuit of the other LED driving circuit.

LED driving system with master-slave architecture

A LED driving system for a LED matrix having a plurality of LEDs connected in parallel. The LED driving system includes a plurality of driving modules. Each one of the plurality of driving modules drives a corresponding one of the plurality of LEDs. The plurality of LEDs are divided into a plurality of groups. The plurality of driving modules drive the plurality of LEDs ON successively group by group. In each one of the plurality of groups, the LESs are driven ON successively row by row, and for each row in each one of the plurality of groups, the LEDs are driven ON successively column by column with a programmed delay time between the LEDs in every two successive columns. Each one of the plurality of driving modules can include a grayscale control module for adjusting a brightness of the corresponding one of the plurality of LEDs.

High brightness LED matrix driving system

A control circuit and method for a voltage converter. The control circuit having a ramp circuit, a reference generating circuit, a comparison circuit and a logic circuit. The ramp circuit generates a ramp signal that decreases from the moment the power switch is turned off and increases from the moment the power switch is turned on. The reference generating circuit generates a reference voltage. The comparison circuit compares the reference voltage with the sum of the feedback voltage and the ramp signal to generate a comparison signal. The logic circuit uses the comparison signal and a clock signal to generate the control signal to control a power switch of the voltage converter.

Constant-frequency control method with fast transient

A smart communication interface for a LED driving system driving a LED matrix having a plurality of LEDs. The smart communication interface may have a data write transaction structure in write mode. The data write transaction structure includes an address code for identifying a corresponding one LED among the plurality of LEDs; an R/W indicating code for indicating whether the smart communication interface is in write mode; and a grayscale command code for indicating a programmed grayscale command value for the corresponding one LED identified by the address code. The smart communication interface may include a data read transaction structure in read mode. The data read transaction structure includes the address code, the R/W indicating code and a grayscale read-back code for indicating a grayscale command value for the corresponding one LED identified by the address code.

Smart communication interface for LED matrix control

A LED driving system for a LED matrix having a plurality of LEDs connected in parallel. The LED driving system includes a plurality of driving modules. Each one of the plurality of driving modules drives a corresponding one of the plurality of LEDs. Each one of the plurality of driving modules can include a local current driver receiving a reference current and providing a driving current to the corresponding one LED, and a local current tuning module receiving a U-bit current tuning command to tune the driving current for the corresponding one LED to reach a desired driving current using the U-bit current tuning command which provides a predetermined number of tuning steps ranging from 0 to 2U.

Current driving control for high brightness LED matrix

Embodiments are disclosed for collaboratively scanning and processing sensor data for building a map of an environment around a group of vehicles. An example an in-vehicle computing system of a vehicle includes a sensor subsystem in communication with an optical sensor, a processor, and memory storing instructions executable by the processor to instruct the optical sensor to scan an assigned region around the vehicle, receive locally scanned data corresponding to the assigned region, process the scanned data to build a first portion of a three-dimensional map, transmit the processed scanned data to at least one other vehicle, receive additional map data from the at least one other vehicle, and build a second, different portion of the three-dimensional map using the received additional map data. In a first example of the in-vehicle computing system, the optical sensor may additionally or alternatively include a Light Detection and Ranging (LiDAR) sensor system.

Collaborative data processing

An off-line regulator has a rectification circuit configured to rectify an AC line voltage into a rectified line voltage, a pass device coupled between the rectified line voltage and a first capacitor, and a converter. The pass device is configured to be turned ON or OFF according to a comparison signal indicating whether the rectified line voltage is over a threshold voltage. The first capacitor delivers an interim voltage into the converter which supplies power to a load. Wherein a second capacitor coupled across a driver which driving the pass device is charged by the first capacitor when the comparison signal is at a first state, and the driver is boosted when the comparison signal is at a second state.

Off-line regulator with pass device and associated method

A light emitting diode (LED) driver circuit controls switching of an output transistor. The LED driver circuit monitors inductor current flowing through an output inductor that is coupled to one or more LEDs. In response to detecting that the inductor current has reached a peak value, the LED driver circuit switches OFF the output transistor. The LED driver circuit switches ON the output transistor in response to detecting zero crossing of the inductor current. The LED driver circuit may detect zero crossing of the inductor current from a gate voltage of the output transistor by detecting for a negative spike.

LED driver circuits with current envelope control

The present invention discloses a step up circuit with output floating for driving a load such as a LED or a series of LEDs in a string. The step up circuit comprises an input port, an output port, an inductor, an input capacitor, an output capacitor, a first switch, a second switch and a third switch. The third switch Sis an additional switch for purpose of high dimming ratio control, short circuit protection and input disconnection realization. Further, the third switch can implement an additional LDO function when the voltage at the input port is larger than the voltage across the load.

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San Jose, CA, United States of America

Zheng Luo