48V Buck Mode LED Driver in SC70 and 2mm × 2mm DFN

The LT3590 is a fixed frequency buck mode converter specifically designed to drive up to 10 LEDs in series from a 48V DC source. Series connection of the LEDs provides identical LED currents of up to 50mA, resulting in uniform brightness and eliminating the need for ballast resistors. A fixed frequency, current mode architecture results in stable operation over a wide range of input voltage and output voltage.

The high switching frequency of 850kHz permits the use of tiny, low profile inductors and capacitors. A single pin performs both shutdown and accurate LED dimming control. The power switch, Schottky diode and control circuitry are all contained inside a space saving SC70 package or 2mm × 2mm DFN package to allow a small converter footprint and lower parts cost.

Applications

* LED Fixed Signage

* Traffic Signs

* Neon Sign Replacement

* 4.5V to 55V Input Voltage Range

* Up to 50mA LED Current

* 80mA, 55V Switch

* Internal Schottky Diode

* 15µA Supply Current in Shutdown

* 500µA Supply Current Operating, Not Switching

* Switching Frequency: 850kHz

* 200mV Feedback Voltage with ±5% Accuracy

* CTRL Input Performs Dimming and Shutdown

* 91% Efficiency (10 LEDs, 50mA)

* Requires Only 1µF Output Capacitor

* 8-Lead SC70 Package

* 6-Lead 2mm × 2mm DFN Package