Description

      The AT383 is a single or multi cell LED driver designed for applications requiring step-up voltage conversion from a very low input voltage. The IC generates constant current pulses that are ideal for driving single or multiple LEDs over a wide range of operating voltages. It includes an on/off enable input that can be driven directly from a photocell array or an open collector/drain logic output. The enable input features an ultra-low voltage drop diode to ground, eliminating the need for a photocell array isolation diode in Garden Light applications.

     The AT383 uses a PFM control technique to drive an internal switching transistor which exhibits a low saturation resistance. This ensures high efficiency, even for input voltages as low as 1.0V.

      The IC can start up under full load and operates down to an input voltage of below 0.9V.

      The AT383 is offered in the space saving TSOT23-5 package or in die form, offering an excellent cost VS performance solution for single cell LED driving applications.

Features

• 85% efficiency

• User adjustable output current

• Single cell operation

• Low saturation voltage

• TSOT23-5 package

• Available also in die form

• Simple application circuit

Applications

• Garden lights

• Door/pathway illumination

• LED flashlight and torches

• LED backlights

• White LED driver

• Gated boost supply generator