Circuit for driving a led string
Assigneeams-OSRAM International GmbH
InventorsThomas TROXLER, Matteo COLOMBO
Life of this patent
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Abstract
The present disclosure relates to a circuit including: a plurality of voltage sources, each configured to generate a respective voltage; a plurality of voltage rails, each coupled with a respective voltage source; a plurality of strings of LED devices, wherein each string comprises a plurality of LED devices connected in series; a switch circuit configured to selectively couple or decouple each string with the voltage rails, wherein, for each string of LED devices, the switch circuit is configured to allow a simultaneous coupling of the string with each voltage rail; and a control circuit configured to, for each string of LED devices, control the switch circuit to selectively couple the string with one or more voltage rails.
Claims20
A circuit comprising:
- a plurality of voltage sources,
- wherein each voltage source of the plurality of voltage sources is configured to generate a respective voltage;
- a plurality of voltage rails,
- wherein each voltage rail of the plurality of voltage rails is coupled with a respective voltage source of the plurality of voltage sources;
- a plurality of strings of light emitting diode, LED, devices,
- wherein each string of LED devices comprises a plurality of LED devices connected in series with one another;
- a switch circuit configured to selectively couple or decouple each string of LED devices with the voltage rails,
- wherein, for each string of LED devices, the switch circuit is configured to allow a simultaneous coupling of the string of LED devices with each voltage rail of the plurality of voltage rails;
- and
- a control circuit configured to, for each string of LED devices control the switch circuit to selectively couple the string of LED devices with one or more voltage rails of the plurality of voltage rails.
A method of driving a plurality of strings of LED devices, the method comprising:
- generating plurality of supply voltages, wherein the plurality of supply voltages are common to a plurality of string of LED devices,
- wherein more than one supply voltage at a time is deliverable to each string of LED devices;
- and
- for each string of LED devices of the plurality of strings of LED devices, selectively enabling a delivery of one or more of the generated supply voltages to that string of LED devices to define a respective voltage drop across the string of LED devices.
A circuit comprising:
- a plurality of voltage sources,
- wherein each voltage source of the plurality of voltage sources is configured to generate a respective voltage;
- a plurality of voltage rails,
- wherein each voltage rail of the plurality of voltage rails is coupled with a respective voltage source of the plurality of voltage sources,
- a string of light emitting diode, LED, devices connected in series with one another;
- a switch circuit configured to selectively couple or decouple the string of LED devices with the voltage rails,
- wherein the switch circuit is configured to allow a simultaneous coupling of the string of LED devices with each voltage rail of the plurality of voltage rails;
- and
- a control circuit configured to control the switch circuit to selectively couple the string of LED devices with one or more voltage rails of the plurality of voltage rails.
Dependencies are inferred from the claim text.