FEATURES

 Simple low parts count

 Internal 32V NDMOS switch

 Up to 1.4A output current

 Single pin on/off and brightness control

using DC voltage or PWM

 Soft Start

 High efficiency (up to 97)

 Wide input voltage range: 6V to 32V

 Output shutdown

 Up to 1MHz switching frequency

 Inherent open-circuit LED protection

 Typical 4 output current accuracy

 High-side current sense

 Hysteretic control: no compensation

 Adjustable constant LED current

 Over temperature protection

 Available in SOT89-5 package

DESCRIPTION

The A8180 is a continuous mode inductive step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage. The device operates from an input supply between 6V and 32V and provides an externally output current up to 1.4A. Depending upon supply voltage and external components, this can provides up to 24 watts of output power.

The A8180 includes the 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 by applying an external control signal to the 'ADJ' pin. The ADJ pin will accept either a DC voltage or a PWM waveform. During DC dimming, this will provide a continuous output current that is proportional to the external applied DC voltage. During the PWM dimming, this will provide a gated output current and the average current is proportional to the duty cycle. Applying a voltage of 0.2V or lower to the ADJ pin turns the output off and switches the device into a low current standby state.

APPLICATIONS

 Low voltage halogen replacement LEDs

 Automotive lighting

 Low voltage industrial lighting

 LED back-up lighting

 Illuminated signs

 LCD TV backlighting