LM27342 Datasheet | National Semiconductor

LM27341/LM27342 2 MHz 1.5/2A Wide Input Range Step-Down DC-DC Regulator with Frequency Synchronization .. December 16, 2008 LM27341/LM27342 2 MHz 1.5A/2A Wide Input Range Step-Down DC-DC Regulator with Frequency Synchronization General Description The LM27341 and LM27342 regulators are monolithic, high frequency, PWM step-down DC-DC converters in 10-pin LLP and 10-pin e MSOP packages. They contain all the active functions to provide local DC-DC conversion with fast transient response and accurate regulation in the smallest possible PCB area. With a minimum of external ponents the LM27341 and LM27342 are easy to use. The ability to drive 1.5A or 2A loads respectively, with an internal 150 mΩ NMOS switch results in the best power density available. The world-class control circuitry allows for on-times as low as 65 ns, thus supporting exceptionally high frequency conversion. Switching frequency is internally set to 2 MHz and synchronizable from 1 to 2.35 MHz, which allows the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequency is very high, efficiencies up to 90% are easy to achieve. External shutdown is included featuring an ultra-low shutdown current of 70 n A. The LM27341and LM27342 utilize peak current-mode control and internal pensation to provide high-performance regulation over a wide range of operating conditions. Additional Features include internal soft-start circuitry to reduce inrush current, pulse-by-pulse current limit, thermal shutdown, and output over-voltage protection. Features - - - - - - - - - - - - Space saving 3 X 3 mm LLP-10 & e MSOP-10 package Wide input voltage range 3 to 20 V Wide output voltage range 1 to 18 V LM27341 delivers 1.5A maximum output current LM27342 delivers 2A maximum output current High switching frequency 2 MHz Frequency synchronization 1.00 MHz < f SW < 2.35 MHz 150 mΩ NMOS switch with internal bootstrap supply 70 n A shutdown current Internal voltage...