News | June 13, 2008

National Semiconductor Introduces 4 MHz Synchronous Step-Down DC-DC Converter For Portable Applications

Santa Clara, CA - National Semiconductor Corp. recently introduced a 4 MHz synchronous step-down DC-DC converter that provides up to a 1A output current over an input voltage range of 2.3V to 5.5V. The LM3691 DC-DC converter is optimized for powering high-performance processors from a single Li-Ion cell battery in mobile phones, personal media players and other mobile devices. A member of National's PowerWise energy-efficient product family, the LM3691 features peak efficiency of 95 percent, low quiescent current to maximize battery life and output voltage precision of +/- 1 percent to power baseband and next-generation applications processors.

National's new LM3691 DC-DC converter is offered in a micro SMD package and features high switching frequency up to 4 MHz that enables use of miniature 1 uH multilayer inductors and tiny 4.7 uF capacitors for a solution size of less than 15 mm squared. Several fixed output voltage options are also available.

Key Features and Benefits of the LM3691 DC-DC Converter

National's LM3691 DC-DC converter features excellent transient performance of +/- 40 mV for stable output voltages. An integrated mode-control pin allows the design engineer to select forced pulse-width modulation (PWM) mode or auto mode, which changes modes between economy or ECO (gated PWM mode) and PWM automatically, depending on the load. In ECO mode, the LM3691 offers superior efficiency and very low quiescent current at 63 uA under light load conditions. ECO mode extends the battery life through reduction of the quiescent current during light load currents and system standby. The LM3691 is offered in a 6-pin, 1.26 mm by 1.56 mm micro SMD package.

For more information on the LM3691 or to order samples and an evaluation board, visit http://www.national.com/pf/LM/LM3691.html.

About National's Power Management Products
National solves power management design problems in space- and energy- constrained applications from feature-rich handheld devices through large line-powered systems. From the novice power designer to the power expert, National's products, people and design tools enable customers to design green- powered systems with complex power supplies in the shortest amount of time. High-performance products include switching regulators such as National's flagship SIMPLE SWITCHER® family, and application-specific products including white-LED drivers and Power-over-Ethernet controllers. More information about National's power management products is available at http://www.national.com/power.

About National's PowerWise Brand
National's PowerWise brand reflects the company's energy-efficient product portfolio. It signifies products with outstanding performance-to-power at the component level, as well as products that provide an outstanding, energy- efficient solution when coupled with other National parts. National's PowerWise family of products features energy-efficient power management, operational amplifiers, interface and data conversion products. For more information about National's PowerWise brand, visit: http://www.national.com/powerwise.

SOURCE: National Semiconductor Corp.