Santa Clara—National Semiconductor says its LM3691, optimized for powering high-performance processors from a single Li-ion battery for mobile phone and personal media player applications, is the industry's smallest 1-amp, 4-MHz synchronous step-down DC/DC converter. The LM3691 is provided in a 6-pin, 1.26-by-1.56 mm micro SMD package. Designers need add only a miniature 1-microhenry inductor and two tiny 4.7 microfarad capacitors to secure a solution size of less than 15 mm2 .
A member of the company's PowerWise family, the LM3691, working from a 2.3 to 5.5-volt input, boasts a peak efficiency of 95 percent and output voltage precision of ±1 percent. Other key features include a maximum output-voltage change of just ±40 mV for a load transient. An integrated mode-control pin allows the design engineer to select the pulse-width modulation (PWM) or auto modes. In the auto mode, the chip selects between economy (ECO, i.e., gated PWM mode) and PWM operation, depending on the load. In ECO mode, the LM3691's quiescent current is 63 microamps under light load conditions.
Datasheet, order samples and evaluation board : Click here.
Availability and pricing : The LM3691 is priced at $2.25 each in 1,000-unit quantities. Several fixed output voltage options are available.
National Semiconductor , 1-800-272-9959, www.national.com