LM3481 Datasheet | National Semiconductor

Description The LM3481 is a versatile Low-Side N-FET high performance controller for switching regulators. It is suitable for use in topologies requiring a low-side FET, such as boost, flyback, SEPIC, etc. The LM3481 can be operated at extremely high switching frequencies in order to reduce the overall solution .. size. The switching frequency of the LM3481 can be adjusted to any value between 100 k Hz and 1 MHz by using a single external resistor or by synchronizing it to an external clock. Current mode control provides superior bandwidth and transient response in addition to cycle-by-cycle current limiting. Current limit can be programmed with a single external resistor. The LM3481 has built in protection features such as thermal shutdown, short-circuit protection and over voltage protection. Power saving shutdown mode reduces the total supply current to 5µA and allows power supply sequencing. Internal soft-start limits the inrush current at start-up. Key Specifications - Wide supply voltage range of 2.97V to 48V - 100 k Hz to 1 MHz Adjustable and Synchronizable clock frequency - ±1.5% (over temperature) internal reference - 10 µA shutdown current (over temperature) Features - - - - - - - - 10-lead MSOP package Internal push-pull driver with 1A peak current capability Current limit and thermal shutdown Frequency pensation optimized with a capacitor and a resistor Internal softstart Current Mode Operation Adjustable Undervoltage Lockout with Hysteresis Pulse Skipping at Light Loads Applications - Distributed Power Systems - Notebook, PDA, Digital Camera, and other Portable Applications - Offline Power Supplies - Set-Top Boxes Typical Application Circuit 201365a5 Typical SEPIC Converter © 2007 National Semiconductor Corporation .national. Connection Diagram 10-Lead Mini SOIC Package (MSOP-10 Package) Package Marking and Ordering Information .. Order Number LM3481MM LM3481MMX Package Type MSOP-10 MSOP-10 Package Marking SJPB...