Linear dual output boost drives up to 6 white LEDs & an OLED display

Content Dam Leds En Ugc 2008 02 Linear Dual Output Boost Drives Up To 6 White Leds An Oled Display Leftcolumn Article Thumbnailimage File
15892 0 thumb Date Announced: 04 Feb 2008

Linear Technology has announced the LT3498, a dual output boost converter featuring a 2.3MHz PWM LED driver and a low noise OLED driver. The device includes an internal power switch and Schottky diode for each channel, all in 2mm x 3mm DFN package.

The LT3498's wide 2.5V to 12V input voltage range enables it to operate from single cell Li-Ion batteries up to fixed 12V input rails, delivering outputs up to 32V. Each of the converters can be independently dimmed or shut down.

From a single cell Li-Ion input, the LED driver channel can drive up to six series 20mA white LEDs while the OLED driver can deliver up to 24mA to a 16V output. This highly integrated power solution is ideal for dual display electronic devices.

The LT3498's LED driver uses a 2.3MHz PWM frequency, keeping switching noise out of critical wireless and audio bands. The device also uses a high side current sense topology, providing a one-wire current source for the LED Driver.

Similarly, the OLED driver uses a unique control scheme that delivers both high efficiency and low output ripple over a wide load current range. This technique guarantees that the switching frequency stays above the audio band for the entire load range, making it ideal for noise-sensitive applications such as MP3 players and cellular phones. Additional features include open LED protection and OLED output disconnect.

The LT3498EDDB is available from stock in a 12-lead 2mm x 3mm DFN package. Pricing starts at $1.95 each for 1,000-piece quantities.

Summary of Features of the LT3498:

* Dual Output Boost for Dual Display Devices
* Drives Up to Six White LEDs & OLED/LCD Bias
* Internal Power Switches and Schottky Diodes
* Independent Dimming & Shutdown
* 200mV High Side Sense on LED Driver Allows “One-Wire Current Source”
* Wide Input Voltage Range: 2.5V to 12V
* Wide Output Voltage Range: Up to 32V
* 2.3MHz PWM Frequency for LED Driver
* PFM for OLED Driver is Non-Audible over Entire Load Range
* Open LED Protection
* OLED Output Disconnect
* Available in 12-Pin 2mm x 3mm DFN Package

UK, Ireland, South Africa and Israel: Alastair Boyd, Linear Technology (UK) Limited Tel: +44 (0)1628 477066 E-mail: North America and General Information: Doug Dickinson, Linear Technology Corporation Tel: (408) 432 1900 ext. 2233 E-mail:


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