Dual output converter

Linear Technology has released the LT3498, a dual-output boost converter featuring a 2.3 MHz PWM LED driver and a low-noise OLED driver.

The device includes an internal power switch and Schottky diode for each channel. The device's wide 2.5 to 12 V input range enables it to operate from single cell Li-Ion batteries up to fixed 12 V input rails, delivering outputs up to 32 V.

Each converter can be independently dimmed or shut down. From a single cell Li-Ion input, the LED driver channel can drive up to six series 20 mA white LEDs while the OLED driver can deliver up to 24 mA to a 16 V output.

The LED driver uses a 2.3 MHz 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 control scheme that delivers both high efficiency and low output ripple over a wide load current range. This ensures the switching frequency stays above the audio band for the entire load range, making it suitable for noise-sensitive applications such as MP3 players and mobile phones.

Additional features include open LED protection and OLED output disconnect.