Demonstrating its leading position in power management innovations, National Semiconductor announced today an integrated high-voltage Cascaded DC-DC controller ideal for power conversion in communications systems. National also introduced today two 100 V power MOSFET drivers designed to work seamlessly with the new controller, providing customers with a chipset solution for communications power systems, automotive power systems, -48 V distributed power systems, motor drive systems, industrial power supplies and Half-Bridge and Full-Bridge converters. The evaluation board for the chipset will be on display at the Applied Power Electronics Conference and Exposition (APEC) 2003, Feb. 9-13, Fontainebleau Hotel, Miami Beach, FL. "The cascaded buck-fed topology is optimized to generate low voltage output(s) efficiently using a cost-effective transformer-isolated power converter," said Paul Greenland, Marketing Director for the power management product line at National Semiconductor. "Existing controllers can not step-down a 48 V input to a sub 1 V output efficiently because the ON-time becomes too narrow. This problem is resolved using National's LM5041-LM5102 chipset. The LM5102 100 V Synchronous Buck Driver drives the step-down converter control and synchronous MOSFETs into a current source inductor [current fed case] or inductor-capacitor filter [voltage-fed case]; this feeds the primary center tap of a push-pull converter isolation transformer. The LM5041 drives the push-pull MOSFETs directly and the buck pre-regulator indirectly through the LM5102 with a PWM signal from its current-mode controller." "Magnetek chose National Semiconductor because of their innovative solution," said Lorenzo Cincinelli, CTO at Magnetek. "The high integration level of the LM5000 series devices will allow us to produce telecom power supply modules with outstanding performances and reliability levels." National's new LM5041 is an integrated current-mode pulse width modulated (PWM) controller incorporating a buck pre-regulator controller synchronized to Push-Pull MOSFET drivers with peak currents of 2 A and programmable dead time. A high-speed controller with a user-programmable 1MHz oscillator, external clock synchronization capability and current limit propagation delay of less than 100 nS, the LM5041 integrates on to a single die unique features such as: Fully Integrated Synchronous Buck Control and Push-Pull Drivers with programmable dead time; Wide range, 15 V-to-100 V start-up bias regulator, High-speed; 2 A peak Push-Pull MOSFET drivers; User-programmable soft-start circuitry; Tiny, thermally enhanced, 16-pin leadless lead frame package (LLP-16, 5 mm X 5 mm); Cascaded controller mates with 100 V Synchronous-Buck driver(s) (LM5101 and LM5102); Allows flexible configurations: interleaved forward, Cascaded Push-Pull, Half or Full-Bridge. The LM5101 and LM5102 are 100 V Half-Bridge power MOSFET drivers designed to drive both the high side and low side N-Channel MOSFETs in a synchronous buck or a Half-Bridge configuration. The LM5101/LM5102 and the LM5041 form a complete chipset solution, providing customers with flexibility to scale power MOSFETs to the power requirements of the dc-dc converter. A second LM5101 can be applied at the Push-Pull outputs of the LM5041 for customers preferring Cascaded Half or Full-Bridge topologies. The LM5102 also provides programmable rise-time control that allows designers to "tune" the power supply for maximum efficiency and limit EMI. The LM5101 and LM5102 feature: 100 V Synchronous-Buck driver, which mates with the LM5041 100 V Cascaded controller; User-programmable turn-ON edge delay feature on the LM5102 driver; Tiny, thermally enhanced 10-pin leadless lead frame package (LLP-10, 4 mm X 4 mm). National Semiconductor's LM5041 Cascaded controller in a LLP-16 package is priced at $2.55 each in 1,000 quantities. The LM5101 and LM5102, both in a LLP-10 package, are priced at $1.75 each and $1.79 each in 1,000 quantities, respectively. The LM5041 and LM5100's will be available for sampling in April with volume production in June and September, respectively.

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