DEVICE FOR DRIVING A LOAD

• US 20100259194A1
• Filed: 11/03/2008
• Published: 10/14/2010
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Shen, Jie, Hente, Dirk, Jacobs, Joseph Hendrik Anna Maria
• Granted Patent: US 8,354,805 B2
• Time in Patent Office: Days
• US Class Current: 315/307
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/375 using buck topology

Abstract

Devices (10) for driving loads (20) such as organic/inorganic light emitting diodes are provided with drivers (11) for driving the loads (20), with converters (12) for converting first parameter signals defining parameters of the loads (20) into second parameter signals each being defined by one bit per time interval, and with digital controllers (13) for controlling the drivers (11) in response to the second parameter signals. The converter (12) may comprise a comparator circuit (40) and a timer circuit (41) for comparing the first parameter signal with a reference signal and for generating the second parameter signal having a respective first or second value of two possible values in case of a respective first or second comparison result. The parameter may be a current flowing through or light emitted by at least a part of the load (20). The driver (11) may be a buck/boost/buck boost/fly back converter.

Claims

1. A device (10) for driving a load (20), comprising

a driver (11) for driving the load (20),

a converter (12) for converting a first parameter signal defining a parameter of the load (20) into a second parameter signal, the second parameter signal having, during each time interval of a group of time intervals, one out of two possible values, and

a digital controller (13) for controlling the driver (11) in response to the second parameter signal.

2. The device (10) as claimed in claim 1, the converter (12) comprising a circuit (40, 41) for comparing the first parameter signal with a reference signal and for generating, during each time interval of a group of time intervals, the second parameter signal having a respective first or second value of the two possible values in case of a respective first or second comparison result.

3. The device (10) as claimed in claim 2, the circuit (40, 41) comprising a comparator circuit (40) and a timer circuit (41).

4. The device (10) as claimed in claim 1, the second parameter signal having a frequency equal to or smaller than a predefined maximum frequency.

5. The device (10) as claimed in claim 1, the load (20) comprising one or more inorganic and/or organic light emitting diodes, and the parameter being a current flowing through at least a part of the load (20) and/or light emitted by at least a part of the load (20).

6. The device (10) as claimed in claim 1, the digital controller (13) being arranged to further control the driver (11) in response to one or more user signals and/or one or more further parameter signals defining one or more further parameters of the load (20).

7. The device (10) as claimed in claim 6, the digital controller (13) being one micro processor and/or one digital signal processor and/or one integrated circuit and/or one field programmable gate array and/or one complex programmable logic device and/or one personal computer and/or one programmable logic array, at least a part of the converter (12) being an external circuit coupled to the digital controller (13) or being an internal circuit forming part of the digital controller (13).

8. The device (10) as claimed in claim 1, the driver (11) comprising a switch (50) that is activated in response to the second parameter signal having a first value of the two possible values and that is deactivated in response to the second parameter signal having a second value of the two possible values.

9. The device (10) as claimed in claim 8, the driver (11) being a buck converter or a boost converter or a buck boost converter or a fly back converter.

10. A method for driving a load (20), comprising the steps of

driving the load (20),

converting a first parameter signal defining a parameter of the load (20) into a second parameter signal, the second parameter signal having, during each time interval of a group of time intervals, one out of two possible values, and

digitally controlling the driving in response to the second parameter signal.