SN3340

SN3340 18V LED driver with internal switch General Description The SN3340 is a continuous mode inductive step-down converter, designed for driving a single LED or multiple series connected LEDs efficiently from a voltage source higher than the required LED voltage. The chip operates from an input supply between 6V and 18V and provides an externally adjustable output current of up to 750mA. Depending upon supply voltage and external components, this can provide up to 12 watts of output power. The SN3340 includes an integrated 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 or a PWM waveform. This will provide either a continuous or a gated output current. Applying a voltage of 0.2V or lower to the ADJ pin turns the output off and switches the chip into a low current standby state. The chip is assembled in SOT23-5 and SOT89-5 package. SOT23-5 is available for 350mA output current application; SOT89-5 is available for 700mA output current application. Application Circuit Features z Simple low parts count z input voltage range: 6V to 18V ， 30V transient capability z Internal 18V power switch z Up to 750mA output current（SOT89-5 package） z Single pin on/off and brightness control using DC voltage or PWM z High efficiency (up to 95% ) z Up to 1MHz switching frequ...