LED features: Linear introduced LTC3220/-1 inductor free low noise high efficiency driver

Linear Technology Corporation (Linear Technology Corporation) launched inductorless, low noise, high efficiency LED driver LTC3220/-1, the device for cellular phone screen and other programmable lighting applications. The device provides 18 separate configurable LED current sources that are completely flexible when programming multiple screens. The display current is set by an accurate internal current reference. The general current source can be digitally controlled, with independent dimming, brightness, flicker and gray control, through the two wire I2C serial interface simple programming; LTC3220 and LTC3220-1 each have a unique I2C address.

The 2.9V to 5.5V input voltage range of the LTC3220/-1 has been optimized for single-cell Li ion / polymer battery applications. Lithium ion battery (nominal value of 3.6V) drive, the efficiency of up to 91%, quiescent current as low as 500uA, to maximize the battery working hours. In addition, the slew rate limited switch reduces the conduction and radiation noise (EMI).

LTC3220/-1 multi mode charge pump operates at low noise and constant frequency, based on LED current source voltage optimization efficiency. The device is powered up to 1 x mode and automatically switches to the boost mode (+ 1.5 x) when the LED current source is in any starting operation, and the subsequent voltage drop switches the device to the doubler (2 x) mode. The internal circuit prevents inrush current and excessive input noise when starting and mode switching. In addition, the device has short circuit and over temperature protection.

LTC3220/-1 uses ultra thin (0.55mm) 28 lead QFN (4mm * 4mm) package, available from stock. The integrated circuit requires only 5 small capacitor LED power supply can be composed of tiny, complete and current controller solution. To buy 1000 units in bulk, each price of $2.35.