An dual output boost converter can drive up to 6 white LED

Linear Technology Corporation (Linear Technology Corporation) launched a dual output boost converter LT3498, this device includes a 2.3MHz PWM LED driver and a low noise OLED driver. Each channel of the LT3498 has an internal power switch and Schottky diode, all of which are included in the 2mm x 3mm DFN package. The device has a wide input voltage range of 2.5V to 12V allowing it to operate with a single input lithium ion cell with up to 12V fixed input rails, thus providing up to 32V output. Each converter can be independently switched on or off. When using a single Li ion battery input, the LED driver channel can drive up to 6 series of 20mA white LED, while the OLED driver can provide up to 24mA/16V output. This highly integrated power solution is ideal for dual display electronics.

The LT3498 LED driver uses 2.3MHz PWM frequency to maintain switching noise beyond critical wireless and audio bands. The device also uses a high side current sensing topology to provide a single line current source for the LED driver. Similarly, the OLED driver uses a unique control circuit to achieve high efficiency and low output ripple over a wide load current range. This method ensures that the switching frequency in the entire load range is maintained above the audio frequency band, which makes the device ideal for noise sensitive applications, such as MP3 players and cellular phones. Other features include LED open circuit protection and OLED output disconnect.

Using 12 lead 2mm x 3mm DFN package LT3498EDDB available from stock. In 1000 pieces for the bulk purchase, each price starts at $1.95.

Performance overview: LT3498

Dual output boost converter for dual display devices

Drive up to 6 white LED and OLED/LCD bias

With internal power switch and Schottky diode

Independent dimming and shutdown

LED drive on the 200mV high side detection allows the realization of "single line current source"

Wide input voltage range: 2.5V to 12V

Wide output voltage range: up to 32V

LED drive 2.3MHz PWM frequency

The OLED driver of the PFM is not audible over the entire load range

LED open circuit protection

OLED output disconnect

12 pin 2mm x 3mm DFN package

Source: International Electronic Business