Dual-output boost convertor combines a 2.3MHz PWM LED driver with a low-noise OLED driver

The LT3498 from Linear Technology is a dual-output boost convertor 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 2 x 3mm DFN package. The LT3498’s wide 2.5 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 convertors 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.