DC-DC Converter, Step-Down DC-DC Converter, National Semiconductor

Step-Down DC-DC Converter for Portable Applications from National Semiconductor

News Release from: National Semiconductor
09/06/2008

National Semiconductor has introduced what it says is the industry's smallest 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.

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.