The LT3519 are fixed frequency step-up DC/DC converters designed to drive LEDs. They feature an internal 45V, 750mA low side switch and Schottky diode. Combining a traditional voltage feedback and a unique floating current sense feedback allows these converters to operate as a constant-voltage source or constant-current source. Internal compensation simplifies applications. These devices feature floating LED current sense pins that provide the most flexibility in choosing a converter configuration to drive the LEDs. The LED current is externally programmable with a 250mV sense resistor. The external PWM provides up to 3000:1 PWM dimming and the CTRL input provides analog dimming.