LT3491EDC#TRMPBF

LT®3491 is a fixed frequency step-up DC/DC converter specifically designed to drive up to six white LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The device features a unique high side LED current sense that enables the part to function as a one wire current source, one side of the LED string can be returned to ground anywhere, allowing a simpler one wire LED connection. Traditional LED driver use a grounded resistor to sense LED current, requiring a 2-wire connection to the LED string. The 2.3MHz switching frequency allows the use of tiny inductors and capacitors. A single pin performs both shutdown and accurate LED dimming control. Typical applications are cellular phones, PDAs, handheld computers, digital cameras, MP3 players, GPS receivers.

• Drives up to six white LEDs from a 3V supply, internal schottky diode
• One pin dimming and shutdown, 27V open LED protection
• Requires only 1µF output capacitor, wide 300:1 true color PWM™ dimming range
• Minimum operating voltage is 2.5V (TA=25°C, VIN=3V, VCTRL=3V)
• Supply current is 4mA (VCAP=16V, VLED=15V, CTRL=3V)
• Switching frequency range from 1.8 to 2.8MHz
• CTRL pin bias current is 100nA typical
• 6-lead plastic DFN package
• Operating temperature range from –40°C to 85°C

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party