OLED power driver circuit

Patent metadata

Field	Value
Publication number	US-9265121-B2
Application number	US-201314064064-A
Country	US
Kind code	B2
Filing date	Oct 25, 2013
Priority date	Oct 25, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

An efficient, cost effective power driver for OLED panels is configured with a small BOM without compromising the display quality. The power driver adopts only one Inverting Buck-Boost Converter (IBBC) to regulate the necessary output voltage for the OLED panel load. The output voltage to drive the OLED panel load is supplied by the IBBC and the positive input of the OLED panel is tied into the input power supply of VIN directly without any switch. A DC-DC converter is provided to generate a reference ground and drive the associated control circuits. The input DC voltage VIN is utilized as a reference voltage for both the IBBC and the DC-DC converter.

First claim

The invention claimed is:

1. A driver circuit for an OLED (organic light-emitting diode) panel load having a first terminal and a second terminal, said driver circuit comprising:
a source of input DC voltage connected to a first node and further connected to the first terminal of the load;
a first Inverting Buck-Boost Converter (IBBC) adapted to receive the input DC voltage and provide a regulated DC output voltage, a negative voltage, to drive the load, said first IBBC comprising:
a first switch coupled between the first node and a second node, the first node disposed between the source of input DC voltage and the second node;
an inductor coupled between the second node and a system ground;
a second switch coupled between the second node and the second terminal of the load; and
a first capacitor coupled between the first terminal and the second terminal of the load;

a first control circuit coupled to said first IBBC, said first control circuit adapted to control switching times of the first switch and the second switch; and
a second DC-DC converter comprising a second capacitor and an associated second control circuit, said second DC-DC converter adapted to generate a reference ground for said first control circuit and said second control circuit and further adapted to generate a positive voltage across the second capacitor.

2. The driver circuit as claimed in claim 1 further comprising a third DC-DC converter adapted to provide additional bias power to the load.

3. The driver circuit as claimed in claim 1 , wherein the first switch and the second switch in said first IBBC are selected from the group of semiconductor devices consisting of MOSFETs, BJTs and IGBTs.

4. The driver circuit as claimed in claim 1 , wherein said second DC-DC converter is selected from the group of converters consisting of a linear regulator, a linear regulator coupled to a buffer amplifier, and a second Inverting Buck-Boost converter (IBBC) comprising switches selected from the group of semiconductor devices consisting of MOSFETs, BJTs and IGBTs.

5. The driver circuit as claimed in claim 2 , wherein said third DC-DC converter being selected from the group of converters consisting of a step-up DC-DC converter like charge pump and Boost Converter comprising switches selected from the group of semiconductor devices consisting of MOSFETs, BJTs and IGBTs.

6. The driver circuit as claimed in claim 1 , wherein said circuit comprises at least one of discrete components, integrated circuits (ICs) for each component, or a monolithic integrated circuit.

7. A driver circuit for a solid state lighting load having a first terminal, a second terminal, and a third terminal, said driver circuit comprising:
a first Inverting Buck-Boost Converter (IBBC) adapted to receive an input DC voltage and provide a regulated DC output voltage to drive the first terminal and the second terminal; and
a third DC-DC converter adapted to provide bias power higher than the input DC voltage to the solid state lighting load at the third terminal, whereby completely turning off a thin film transistor connected in series with an LED within the solid state lighting load.

8. The driver circuit as claimed in claim 7 , wherein a first switch and a second switch in said first IBBC are selected from the group of semiconductor devices consisting of MOSFETs, BJTs and IGBTs.

9. The driver circuit as claimed in claim 7 , wherein said third DC-DC converter being selected from the group of converters consisting of a step-up DC-DC converter like charge pump and Boost Converter comprising switches selected from the group of semiconductor devices consisting of MOSFETs, BJTs and IGBTs.

10. The driver circuit as claimed in claim 7 , wherein said circuit comprises at least one of discrete components, integrated circuits (ICs) for each component, or a monolithic integrated circuit.

11. A method of driving an OLED (organic light-emitting diode) panel load, said method comprising the following steps:
providing an Inverting Buck-Boost Converter (IBBC) to receive an input DC voltage and drive the OLED panel load with a regulated output voltage;
providing a first DC-DC converter to generate a reference ground and drive associated control circuits;
providing an additional DC-DC converter to provide bias power higher than the input DC voltage to the OLED panel load, whereby completely turning off a thin film transistor connected in series with the OLED; and
utilizing the input DC voltage as a reference voltage for the IBBC and the first DC-DC converter.

Assignees

• Lee Gilbert S
• Alpha & Omega Semiconductor

Inventors

• Lee Gilbert S

Classifications

• H05B45/60 Primary

  Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED] · CPC title

• H05B33/0896 Primary

  Electricity · mapped topic

• Y02B20/30

  Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED] · CPC title