LM2734 Datasheet | National Semiconductor

LM2734 Thin SOT23 1A Load Step-Down DC-DC Regulator October 2004 LM2734 Thin SOT23 1A Load Step-Down DC-DC Regulator General Description The LM2734 regulator is a monolithic, high frequency, PWM step-down DC/DC converter in a 6-pin Thin SOT23 package. It provides 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 and online design support through WEBENCH™, the LM2734 is easy to use. The ability to drive 1A loads with an internal 300mΩ NMOS switch using state-of-the-art 0.5µm Bi CMOS technology results in the best power density available. The world class control circuitry allows for on-times as low as 13ns, thus supporting exceptionally high frequency conversion over the entire 3V to 20V input operating range down to the minimum output voltage of 0.8V. Switching frequency is internally set to 550k Hz (LM2734Y) or 1.6MHz (LM2734X), 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 shutdown is included, featuring an ultra-low stand-by current of 30n A. The LM2734 utilizes 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 n n n n n n n n n n n Thin SOT23-6 package 3.0V to 20V input voltage range 0.8V to 18V output voltage range 1A output current 550k Hz (LM2734Y) and 1.6MHz (LM2734X) switching frequencies 300mΩ NMOS switch 30n A shutdown current 0.8V, 2% internal voltage reference Internal soft-start Current-Mode, PWM operation WEBENCH online design tool Applications n n n n n n n Local Point of Load Regulation Core Power in HDDs Set-Top Boxes Battery...