The LN2119B123MR-G with SOT-23-5L is a switching DC-DC controller from the National Semiconductor Corporation's Linear Solutions line. It is a high-efficiency, low-noise voltage regulator that is available in the small, surface-mount SOT-23-5L package. The device has an enable input, an adjustable operating frequency up to 1.2 MHz, and a fixed internally compensated output voltage rail of 1.23V. Its on-chip logic provides low-dropout control, output current regulation, and protection from over-temperature, inrush current, and under-voltage conditions. It is certified as RoHS (Restriction on Hazardous Substances) compliant, making it suitable for a wide range of commercial and industrial applications.