National Semiconductor has introduced what it describes as 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.

According to NatSemi, the LM3691 DC-DC converter is optimised 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.

Features

• 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.

Available now, the LM3691 is priced at $2.25 each in 1,000-unit quantities.

For more information on the LM3691 or to order samples and an evaluation board, visit

See http://www.national.com/pf/LM/LM3691.html