Semtech introduces the SC4501, SC4502 and SC4502H, a family of current-mode, adjustable-frequency, step-up (boost) converters with an internal 2 A, 40 V switch. Each converter can be adapted in a variety of topologies, such as boost, sepic and flyback, for generating high output voltage from multi-cell alkaline, NiCd, NiMH or single-cell Li-ion batteries. The boost converters operate from input voltages as low as 1.4 V to generate outputs to 40 V at efficiencies over 90%. Switching frequency can be programmed using a single resistor to select the desired value between 250 kHz and 2 MHz. A high frequency of operation enables the system designer to minimize external component size and avoid interference with noise sensitive frequency bands in the system.