The LM2738 regulator is a monolithic, high frequency, PWM step-down DC/DC converter in an 8-pin LLP or 8-pin eMSOP package. It provides all the active functions for local DC/DC conversion with fast transient response and accurate regulation in the smallest possible PCB area. With a minimum of external components, the LM2738 is easy to use. The ability to drive 1.5A loads with an internal 250m NMOS switch using state-of-the-art 0.5m BiCMOS technology results in the best power density available. Switching frequency is internally set to 550kHz (LM2738Y) or 1.6MHz (LM2738X), allowing the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequencies are very high, efficiencies up to 90% are easy to achieve. External enable is included, featuring an ultra-low stand-by current of 400nA. The LM2738 utilizes current-mode control and internal compensation to provide highperformance regulation over a wide range of operating conditions. Additional features include internal soft-start circuitry to reduce in-rush current, cycle-by-cycle current limit, thermal shutdown, and output over-voltage protection.