Linear dual output boost drives up to 6 white LEDs & an OLED display 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
Contact
UK, Ireland, South Africa and Israel:
Alastair Boyd, Linear Technology (UK) Limited
Tel: +44 (0)1628 477066
E-mail: aboyd@linear.com
North America and General Information:
Doug Dickinson, Linear Technology Corporation
Tel: (408) 432 1900 ext. 2233
E-mail: ddickinson@linear.com
E-mail: uksales@linear.com Web Site: www.linear.com | 
