LM2831 Datasheet | National Semiconductor

Description The LM2831 regulator is a monolithic, high frequency, PWM step-down DC/DC converter in a 5 pin SOT23 and a 6 Pin LLP 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, the LM2831 is easy to use. The ability to drive 1.5A loads with an internal 130 mΩ PMOS switch using state-of-the-art 0.5 µm Bi CMOS technology results in the best power density available. The worldclass control circuitry allows on-times as low as 30ns, thus supporting exceptionally high frequency conversion over the entire 3V to 5.5V input operating range down to the minimum output voltage of 0.6V. Switching frequency is internally set to 550 k Hz, 1.6 MHz, or 3.0 MHz, allowing the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequency is high, efficiencies up to 93% are easy to achieve. External shutdown is included, featuring an ultra-low stand-by current of 30 n A. The LM2831 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 Space Saving SOT23-5 Package Input voltage range of 3.0V to 5.5V Output voltage range of 0.6V to 4.5V 1.5A output current High Switching Frequencies 1.6MHz (LM2831X) 0.55MHz (LM2831Y) 3.0MHz (LM2831Z) 130mΩ PMOS switch 0.6V, 2% Internal Voltage Reference Internal soft-start Current mode, PWM operation Thermal Shutdown Over voltage protection n n n n n n Applications n n n n n Local 5V to Vcore Step-Down Converters Core Power in HDDs Set-Top Boxes USB Powered Devices DSL Modems Typical Application Circuit 20174864 20174881 © 2006 National Semiconductor Corporation DS201748 .national. Con...