Buck Regulators Widen Input Range

Expanding the PowerWise portfolio, the 2.5A LM3102 and 750-mA LM3103 lay claim to being the industry’s first synchronous buck regulators with an input voltage range from 4.5V to 42V. Both devices operate with efficiencies up to 97% and employ a constant on-time control scheme, which requires no loop compensation. Sporting a programmable switching frequency up to 1 MHz, they also enlist a patented flywheel current injection control that allows for the use of ceramic capacitors rather than tantalums. The LM3102 supplies up to 2.5A of current with an output voltage as low as 0.8V while the LM3103 delivers up to 750 mA with outputs down to 0.6V. Both regulators run in discontinuous mode to boost efficiency during light-load conditions. Other shared features include programmable soft-start, valley-current limit, output over-voltage protection, and thermal shutdown. Prices for the LM3102 in a 20-pin TSSOP with exposed pad and LM3103 in a 16-pin TSSOP are $2.65 and $2 each/1,000, respectively. NATIONAL SEMICONDUCTOR CORP., Santa Clara, CA. (800) 272-9959.