LM5000 Datasheet | National Semiconductor

Description The LM5000 is a monolithic integrated circuit specifically designed and optimized for flyback, boost or forward power converter applications. The internal power switch is rated for a maximum of 80V, with a current limit set to 2A. Protecting the power switch are current limit and thermal shutdown circuits. The current mode control scheme provides excellent rejection of line transients and cycle-by-cycle current limiting. An external pensation pin and the built-in slope pensation allow the user to optimize the frequency pensation. Other distinctive features include softstart to reduce stresses during start-up and an external shutdown pin for remote ON/OFF control. There are two operating frequency ranges available. The LM5000-3 is pin selectable for either 300k Hz (FS Grounded) or 700k Hz (FS Open). The LM5000-6 is pin selectable for either 600k Hz (FS Grounded) or 1.25MHz (FS Open). The device is available in a low profile 16-lead TSSOP package (available now) or a thermally enhanced 16-lead LLP package (ing in Q3CY03). Features n 80V internal switch n Operating input voltage range of 3.1V to 40V n Pin selectable operating frequency 300k Hz/700k Hz (-3) 600k Hz/1.25MHz (-6) n Adjustable output voltage n External pensation n Input undervoltage lockout n Softstart n Current limit n Over temperature protection n External shutdown n Small 16-Lead TSSOP or 16-Lead LLP package Applications n n n n n Flyback Regulator Forward Regulator Boost Regulator DSL Modems Distributed Power Converters Typical Application Circuit LM5000 Flyback Converter © 2003 National Semiconductor Corporation DS200319 .national. Connection Diagram Top View Ordering Information Order Number LM5000-3MTC LM5000-3MTCX LM5000SD-3 LM5000SDX-3 LM5000SD-6 LM5000SDX-6 Package Type TSSOP-16 TSSOP-16 LLP-16 LLP-16 LLP-16 LLP-16 NSC Package Drawing MTC16 MTC16 SDA16 SDA16 SDA16 SDA16 ing in Q3CY03 Supplied As 94 Units, Rail 2500 Units, Tape and Reel Pin...