描述 Description

The LM2738 regulator is a monolithic, high-frequency, PWM step-down DC-DC converter in an 8-pin WSON or 8-pin MSOP-PowerPAD 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 1.5-A loads with an internal 250-m? NMOS switch using state-of-the-art 0.5-μm BiCMOS technology results in the best power density available. Switching frequency is internally set to 550 kHz (LM2738Y) or 1.6 MHz (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 ultralow standby current of 400 nA. The LM2738 utilizes current-mode control and internal compensation to provide high-performance 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.

特性 Features

? Space-Saving WSON and MSOP-PowerPAD Packages
? 3-V to 20-V Input Voltage Range
? 0.8-V to 18-V Output Voltage Range
? 1.5-A Output Current
? 550-kHz (LM2738Y) and 1.6-MHz (LM2738X) Switching Frequencies
? 250-m? NMOS Switch
? 400-nA Shutdown Current
? 0.8-V, 2% Internal Voltage Reference
? Internal Soft-Start
? Current-Mode, PWM Operation
? Thermal Shutdown