Globalfoundries Inc.

Nxp B.v.

Infineon Technologies Canada Inc.

Ramesh G Karpur

Rajesh Swaminathan

Ashutosh Ravindra Joharapurkar

Zhemin Zhang

Hrishikesh Bhagwat

Krishnadas Bhagwat

Somnath Samantha

Abhisek Khare

Sumon K Bose

Marco A Zuniga

Abhishek Jain

Nan Xing

Pankaj Agrawal

Henk Boezen

Yalong Li

Jitendra Prabhakar Harshey

Lucas Andrew Milner

Rohan Samsi

Krishnaswamy Nagaraj

Krishnaiah Bellamkonda

Suraj Somashekara Kumar

Ashutosh Kumar

Abhisek Jain

A bidirectional current sense circuit allowing for sensing of power current passing through a power field-effect transistor, regardless of the direction of the power current. The bidirectional current sense circuit outputs a current sense signal representing the power current onto a current sense output node. The bidirectional current sense circuit includes the power field-effect transistor, and two current sense circuits. One of the current sense circuits senses the power current when the power current flows in the positive direction. The other current sense circuit senses the power current when the power current flows in the negative direction.

Bidirectional current sense for power field-effect transistor

A circuit that is capable of generating a negative voltage on a negative voltage supply node. The circuit includes a negative voltage generation circuit, an oscillator and an oscillator control signal generator. The negative voltage generation circuit generates a negative voltage on the negative voltage supply node in response to receiving a signal from the oscillator. The negative voltage generated by the negative voltage generation circuit depends upon the frequency of the signal from the oscillator. The oscillator control signal generator controls the frequency of the signal from the oscillator by sensing the negative voltage present on the negative voltage supply node, and by increasing or decreasing the frequency of the signal from the oscillator accordingly. Thus, charge is replenished to the negative voltage supply node to more closely match the drawing of charge from that negative voltage supply node, thereby more accurately generating the negative voltage.

Negative voltage generator

The present invention discloses system and method to regulate primary side current using an event driven architecture in LED circuit. The system () performs a primary side regulation (PSR) of isolated or non-isolated LED driver topology such as fly back system. The primary side peak voltage or current is regulated to achieve desired secondary side currents without the need of additional external components. The architecture combines firmware and hardware to realize PSR. The method () effectively combines input wave shaping (Active PFC), dimming and PSR to achieve accurate secondary side currents. The method () corrects the Peak Regulation Voltage or current (PRV) of primary loop to meet desired half cycle reference voltage or current, which in turn achieves the desired secondary loop current in LED circuit.

System and method to regulate primary side current using an event driven architecture in LED circuit

The present invention discloses a system and method for active power factor correction and current regulation in led circuit. The system () used in the LED driver circuit performs active PFC and current regulation through the dynamic input current wave shaping by limiting peak currents. The dynamic waveshaping scheme is realized through hardware and firmware and is used to strike an optimal balance between current accuracy, Power factor, THD and peak inductor currents. The system () is versatile enough to improve PF and current accuracy in LED circuits and indimmers circuits.

System and method for active power factor correction and current regulation in LED circuit

A buck converter is described having a buck converter output for outputting an output supply voltage; a first power supply domain operably coupled to a power source; a second power supply domain; a power supply controller coupled to the first power supply domain, the second power supply domain and the buck converter output; wherein the power supply controller is configured to supply power to the second power supply domain from the first power supply domain or the buck converter output, in dependence of the buck converter output supply voltage. Changing the current supplied to the second power supply domain to the buck converter output may reduce the quiescent current consumption from a battery power source, prolonging battery life.

Buck converter

According to an example embodiment of the present disclosure, a method is provided for controlling a light-emitting-diode (LED) circuit. The method includes receiving a direct current to direct current (DC-to-DC) control signal at a DC-to-DC converter. A DC voltage is generated from an input DC voltage source. The DC voltage has a voltage level that is set according to the DC-to-DC control signal. The DC voltage is provided to an LED circuit output. The DC voltage level from the DC-to-DC converter is determined. The DC-to-DC converter control signal is generated in response to the determined DC voltage level. The LED circuit is determined to have a short circuit based upon the determined DC voltage. In response to determining that the LED circuit has a short circuit, the DC-to-DC converter is disabled from providing the DC voltage to the output for powering an LED circuit.

LED short circuit protection

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Bengaluru, India

Ramesh G Karpur