■ DESCRIPTION
The UTC L4075 is a continuous conduction mode inductive step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the total LEDs chain voltage. The chip operates from an input supply between 6V and 40V and provides an externally adjustable output current of up to 750mA (SOT89-5). Depending upon supply voltage and external components, this can provide up to 30W of output power.
The UTC L4075 includes an integrated output switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current.
Output current can be adjusted linearly by applying an external control signal to the ADJ pin. The ADJ pin will accept either a DC voltage dimming or a wide range of pulsed dimming. This will provide either a continuous or a gated output current.
Applying a voltage of 0.2V or lower to the ADJ pin can turn the output off and switch the chip into a low current standby state.

■ FEATURES
* 6V~40V input voltage range
* Simple low parts count
* Internal 40V power switch
* High efficiency up to 95%
* Typical 5% output current accuracy
* Single pin on/off and brightness control using DC voltage or PWM
* Up to 1MHz switching frequency
* Protection features:
   Open-circuit LED Protection
   Thermal shutdown Protection