Power-Management ICs Enhance OLEDs, White LED Backlighting

May 24, 2004

An organic LED (OLED) dc-dc converter IC and a white LED charge pump enhance OLEDs and white LED backlighting while providing flexible power control and efficiency. Developed by Texas Instruments, the TS65130 OLED driver boasts adjustable...

Roger Allan

An organic LED (OLED) dc-dc converter IC and a white LED charge pump enhance OLEDs and white LED backlighting while providing flexible power control and efficiency.

Developed by Texas Instruments, the TS65130 OLED driver boasts adjustable output voltages from −12 to 15 V and an 800-mA switch current limit. It's up to 89% efficient at the positive output-voltage rail and 81% efficient at the negative output-voltage rail. Also, its power-save mode brings high efficiency at low load currents.

The TS65130 fits charge-coupled-device (CCD) sensor supply applications in cell phones, PDAs, digital cameras, and camcorders. With an input voltage of 2.7 to 5.5 V, it can be powered from single-cell lithium-ion (Li-Ion) and multicell nickel-metal-hydride (NiMH), nickel-cadmium (NiCd), and alkaline batteries.

This device comes in a small, 4- by 4-mm QFN package. It operates at a fixed-frequency pulse-width-modulated (PWM) signal of 1.25 MHz minimum, permitting the use of tiny 4.7-µH inductors. Independent enable pins permit power-up and power-down sequencing for both outputs.

TI's TPS60230 white LED charge-pump IC manages the power supplied to the display backlight in cell-phone, PDA, digital-camera, and camcorder applications without the need for an inductor. Its regulated output current features 0.3% matching over temperature. Efficiency is up to 87%.

The device can drive up to five LEDs at 25 mA each and switches at 1 MHz, enabling the use of capacitors under 1 µF. Brightness levels for each LED are adjustable through PWM dimming functions on two enable input pins. Housed in a 3- by 3-mm QFN package, the IC features an input-voltage range of 2.7 to 6.5 V and internal soft-start limits for inrush current.

In lots of 1000, the TPS65130 costs $2.95 each, and the TPS60230 charge pump costs $1.55 each.

Texas Instrumentswww.ti.com
(800) 477-8924

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About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.