New Industry Products

National Semi Introduces High-Voltage, Monolithic Two-Switch Forward DC-DC Regulator

December 20, 2007 by Jeff Shepard

National Semiconductor Corp. introduced what is describes as the industry’s first high-voltage, monolithic two-switch forward dc-dc regulator for power supply designs in telecommunication, automotive and industrial applications. The highly integrated LM5015 features an ultra-wide input voltage range from 4.25 to 75V and maximum switching frequency to 750kHz. The LM5015 enables easy implementation of either isolated or non-isolated dc-dc converters using a minimum of external components.

Offered in a small TSSOP package, the LM5015 integrates two 75V N-Channel MOSFET switches for a reduced system component count and small size. The two-switch forward architecture reduces system losses and noise. The LM5015 joins National’s high-voltage dc-dc regulator product line which includes the LM5001 and LM5002 high-voltage switch-mode regulators.

The LM5015 high-voltage switch-mode regulator are said to feature all of the functions necessary to implement efficient two-switch forward and two-switch flyback power converters with a minimum of external components. The regulator integrates high-side and low-side 75V N-Channel MOSFETs with a minimum 1A peak current limit. The voltage across the MOSFETs employed in the two-switch topology is clamped to the input voltage, allowing the input voltage range to approach the rating of the MOSFETs. The regulator control method is based on current-mode control, providing inherent ease-of-loop compensation and line feed-forward for superior rejection of input transients.

The operating frequency of the LM5015 is set with a single resistor and is programmable up to 750 kHz. The oscillator can also be synchronized to an external clock. Additional protection features include cycle-by-cycle current limiting, thermal shutdown, under-voltage lockout and remote shutdown capability. The LM5015 is offered in a 14-pin TSSOP package featuring an exposed die attach pad to enhance thermal dissipation.

The LM5015 is available now and priced at $2.05 each in 1,000-unit quantities.