New Industry Products

National Semi Unveils DC/DC Controller-Drivers

February 03, 2003 by Jeff Shepard

National Semiconductor (Santa Clara, CA) announced an integrated, high-voltage, cascaded dc-dc controller suitable for power conversion in computer and communications systems. National also introduced two 100V power MOSFET drivers that work with the new controller, providing a chipset solution for communications, automotive power, -48V distributed power and motor drive systems; industrial power supplies; and half-bridge and full-bridge converters.

The LM5041-LM5102 chipset simplifies control, drive and regulation in cascaded buck-fed topologies. The LM5102 100V synchronous buck driver drives the step-down converter control and synchronous MOSFETs into the current source inductor or inductor-capacitor filter; which 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 pulse-width modulated signal from its current-mode controller.

National’s LM5041 is an integrated, current-mode, pulse-width modulated controller incorporating a buck pre-regulator controller synchronized to push-pull MOSFET drivers with peak currents of 2A and programmable dead time. The LM5041 features a wide-range, 15V to 100V start-up bias regulator; high-speed, 2A peak push-pull MOSFET drivers; user-programmable, soft-start circuitry; and a tiny, thermally enhanced, 16-pin, leadless lead-frame package that measures 5mm x 5mm.

The LM5101 and LM5102 are 100V, 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 and LM5102 feature a 100V synchronous-buck driver that mates with the LM5041 100V cascaded controller; a user-programmable, turn-on edge delay feature on the LM5102 driver; and a tiny, thermally enhanced, 10-pin, leadless lead-frame package that measures 4mm x 4mm.

The LM5041 controller in a LLP-16 package is priced at $2.55 each in 1,000-unit quantities. The LM5101 and LM5102, both in a LLP-10 package, are priced at $1.75 each and $1.79 each in 1,000-unit quantities, respectively. The LM5041, LM5101 and LM5102 will be available for sampling in April 2003 with volume production in June and September, respectively.