Hybrid driving scheme for RGB color tuning
AssigneeLumileds LLC
InventorsYifeng Qiu, John Grant
Life of this patent
Estimating the term…
Abstract
A device includes an analog current division circuit configured to divide an input current into a first current and a second current, and a multiplexer array including a plurality of switches to provide the first current to a first of three colors of LEDs and the second current to a second of three colors of LEDs simultaneously during a first portion of a period, the first current to the second of three colors of LEDs and the second current to a third of three colors of LEDs simultaneously during a second portion of the period, and the first current to the first of three colors of LEDs and the second current to the third of three colors of LEDs simultaneously during a third portion of the period.
Claims20
A circuit comprising:
- a current division circuit configured to divide an input current into a first current and a second current;
- and
- a multiplexer array arranged to receive the first current and the second current, the multiplexer array including a plurality of switches arranged to, for each period of a plurality of periods:
- provide the first current to a first output and the second current to a second output substantially simultaneously exclusively during a first portion of the period,
- provide the first current to the second output and the second current to a third output substantially simultaneously exclusively during a second portion of the period, and
- provide the first current to the first output and the second current to the third output substantially simultaneously exclusively during a third portion of the period.
A circuit board comprising:
- a temperature sensor arranged to determine a temperature of the circuit board;
- a multiplexer array arranged to receive a first current and a second current, the multiplexer array including a plurality of switches arranged to, for each period of a plurality of periods:
- provide the first current to a first output and the second current to a second output substantially simultaneously exclusively during a first portion of the period,
- provide the first current to the second output and the second current to a third output substantially simultaneously exclusively during a second portion of the period, and
- provide the first current to the first output and the second current to the third output substantially simultaneously exclusively during a third portion of the period;
- and
- a microcontroller configured to receive an indication of the temperature of the circuit board from the temperature sensor and compensate for changes caused by changes in the temperature of the circuit board.
A method for providing currents to a plurality of loads on a circuit board, the method comprising:
- dividing an input current on the circuit board into a first current and a second current;
- for each period of a plurality of periods:
- providing, to a first load, the first current to a first output and the second current to a second output substantially simultaneously exclusively during a first portion of the period,
- providing, to a second load, the first current to the second output and the second current to a third output substantially simultaneously exclusively during a second portion of the period, and
- providing, to a third load, the first current to the first output and the second current to the third output substantially simultaneously exclusively during a third portion of the period;
- monitoring a temperature of the circuit board;
- and
- adjusting the input current for changes caused by changes in the temperature of the circuit board.
Dependencies are inferred from the claim text.