SINGLE SWITCH DRIVER DEVICE HAVING LC FILTER, FOR DRIVING A LOAD, IN PARTICULAR AN LED UNIT

• US 20140117868A1
• Filed: 06/11/2012
• Published: 05/01/2014
• Est. Priority Date: 06/17/2011
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Lopez, Toni, Elferich, Reinhold
• Granted Patent: US 9,210,749 B2
• Time in Patent Office: Days
• US Class Current: 315/201
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

The present invention relates to a driver device (50a-50f) and a corresponding method for driving a load (22), in particular an LED unit comprising one or more LEDs (23). The proposed driver device comprises power input terminals (51, 52) for receiving a rectified supply voltage from an external power supply, power output terminals (53, 54) for providing a drive voltage and/or current for driving a load (22), a single stage power conversion unit (66a, 66b, 66c) coupled to the power input terminals (52) comprising a single switching element (60) and an energy storage element (Ch), both coupled to a switch node (55), wherein the power output terminals (53, 54) are represented by the output of said stage power conversion unit, a filter unit (68) coupled to said switch node (55), said filter unit comprising a filter inductor (Lc) and a filter capacitor (Cs), and a control unit (58) for controlling said switching element (60).

Claims

1. A driver device for driving an LED unit comprising one or more LEDs, said driver device comprising:

power input terminals for receiving a rectified supply voltage from an external power supply,

power output terminals for providing a drive voltage and/or current for driving a load,

a single stage power conversion unit coupled to the power input terminals comprising a single switching element and an energy storage element, both coupled to a switch node, wherein the power output terminals are represented by the output of said stage power conversion unit,

a first inductor coupled between the switch node and a power input terminal,

a filter unit coupled to said switch node, said filter unit comprising a filter inductor and a filter capacitor, and

a control unit for controlling said switching element, wherein

said energy storage element is coupled between said switch node and an intermediate node,

a second inductor is coupled between said intermediate node and a power output terminal, and

a diode is coupled between said intermediate node and a power output terminal.

2. The driver device as claimed in claim 1, wherein said filter inductor and said filter capacitor are coupled in series, wherein a high voltage terminal of said filter unit is coupled to said switch node.

3. The driver device as claimed in claim 2, wherein a low voltage terminal of said filter unit is coupled to a reference potential, in particular a ground potential, and/or a power input terminal coupled to a power output terminal.

4. The driver device as claimed in claim 2, wherein a low voltage terminal of said filter unit is coupled to a power output terminal that is not directly connected to a power input terminal.

5. The driver device as claimed in claim 1, wherein said single stage power conversion unit comprises a Cuk-type, SEPIC-type or Zeta-type converter.

6. The driver device as claimed in claim 1, wherein said single stage power conversion unit comprises a Cuk-type converter, said switching element is coupled between the switch node and the first output terminal, the second inductor is coupled between said intermediate node and a first power output terminal, and the diode is coupled between said intermediate node and a second power output terminal.

7. The driver device as claimed in claim 1, wherein said single stage power conversion unit comprises a SEPIC-type converter, said switching element is coupled between the switch node and the first output terminal, the second inductor is coupled between said intermediate node and a second power output terminal, and the diode is coupled between said intermediate node and a first power output terminal.

8. The driver device as claimed in claim 6, wherein said switching element is coupled between said switch node and a second power input terminal.

9. The driver device as claimed in claim 1, wherein said single stage power conversion unit comprises a Zeta-type converter, said switching element is coupled between a first power input terminal (51) and the switch node, a first diode is coupled in series to said first inductor, the second inductor is coupled between said intermediate node and a first power output terminal, and the second diode coupled between said intermediate node and a second power output terminal.

10. The driver device as claimed in claim 1, further comprising an input decoupling capacitor coupled between the power input terminals.

11. The driver device as claimed in claim 1, further comprising an output decoupling capacitor coupled between the power output terminals.

12. The driver device as claimed in claim 1, wherein a second power input terminal and a second power output terminal are connected to a reference potential.

13. The driver device as claimed in claim 1, further comprising a rectifying unit for rectifying an AC supply voltage, into said rectified periodic supply voltage.

14. The driver device as claimed in claim 1, wherein the control unit is adapted for keeping the output current constant, to keep the voltage across the energy storage element below a predetermined threshold and/or to shape the input current.

15. A light apparatus comprising:

a light assembly comprising one or more LED units comprising one or more LEDs, and

a driver device for driving said light assembly as claimed in claim 1.