SC189 Step Down Regulators Semtech SC189 Step Down Regulators delivers up to 1.5A output current in either an ultra-small 2mm x 2mm, low profile package, or a low-cost SOT23-5 package. With only three external filter components, the SC189 is a complete step-down regulator solution. The SC189 Regulators feature an input voltage range of 2.9V to 5.5V with either factory-programmed outputs from 1.0V to 3.3V or adjustable output via an external resistor divider.