LM26420 Datasheet | National Semiconductor

Description The LM26420 regulator is a monolithic, high frequency, dual PWM step-down DC/DC converter in a 16 Pin LLP and a 20 Pin e TSSOP 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 LM26420 is easy to use. The ability to drive two 2.0A loads with an internal 75 mΩ PMOS top switch and an internal 50 mΩ NMOS bottom switch using state-of-the-art 0.5 µm Bi CMOS technology results in the best power density available. The world-class 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 0.8V. Switching frequency is internally set to 550 k Hz or 2.2 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 ultralow stand-by current. The LM26420 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, power good indicators, precision enables, and output over-voltage protection. Features - - - - - - - - - - - - - - - Input voltage range of 3.0V to 5.5V Output voltage range of 0.8V to 4.5V 2.0A output current per output High Switching Frequencies 2.2MHz (LM26420X) 0.55MHz (LM26420Y) 75mΩ PMOS switch 50mΩ NMOS switch 0.8V, 1.5% Internal Voltage Reference Internal soft-start Independent power good for each output Independent precision enable for each output Current mode, PWM operation Thermal Shutdown Over voltage protection Start-up into Pre-biased Output Loads Outputs are 180° out of phase Applications - - - - - -...