The LT3955EUHE#PBF is a DC/DC Converter designed to operate as a constant-current source and constant-voltage regulator. It features an internal low-side N-channel MOSFET rated for 80V/3.5A. The LT3955 is ideally suited for driving high current LEDs, but also has features to make it suitable for charging batteries and super-capacitors. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. A voltage feedback pin serves as the input for several LED protection features and also makes it possible for the converter to operate as a constant-voltage source. A frequency adjust pin allows the user to program the frequency from 100kHz to 1MHz to optimize efficiency, performance or external component size. The PWM input can be configured to self-oscillate at fixed frequency with duty ratio programmable from 4 to 96%. When driven by an external signal, the PWM input provides LED dimming ratios of up to 3000:1.
Programmable PWM dimming signal generator
Constant current (±3%) and constant-voltage (±2%) regulation
(EN)
