40V, 2A, 2MHz Step-up DC/DC Converters Deliver Highly Compact Designs

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 1.4V to generate outputs to 40V at efficiencies over 90 percent. Switching frequency can be programmed using a single resistor to select the desired value between 250kHz and 2MHz. 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.

A small inductor and ceramic capacitors keep the total solution footprint compact while minimizing total solution cost.

The SC4501, with a low Vsat 220mV switch, delivers up to 2A at 32V. The SC4502 and SC4502H feature 210mV and 250mV Vsat switches, respectively, to supply up to 1.4A at 32V for the SC4502 and 1.4A at 40V for the SC4502H. The boost converter family is ideal for driving up to 10 white LEDs in series configuration for backlighting in cell phones, PDAs, and automotive displays. The high current internal switches also make them well suited for generating bias voltages in LCD panels and for system voltages in battery operated systems such as portable DVDs, digital video cameras, portable medical equipment and many other consumer portables.

The SC4502 and SC4502H include most of the features of the SC4501 and are further optimized for high efficiencies at light loads. Equipped with a smaller 1.4A switch, they have a low shut-down supply current of 10µA. In battery-operated appliances where battery conservation is crucial, the SC4502 and SC4502H are highly attractive choices. Device family includes additional features such as programmable soft start and programmable under-voltage lockout (UVLO) which help eliminate inrush currents during start-up and protect the system from line voltage transients, thereby ensuring reliable system performance.

The SC4501 is available in a 3mm x 3mm, 10-pin MLPD and in an 8-pin MSOP package. The SC4502 and SC4502H are offered in the 3mm x 3mm 10-pin MLPD package only. Both packages incorporate a special thermal design for high-power applications. The lead-free design of the devices meets worldwide environmental and regulatory requirements including the European Union’s Restriction on Hazardous Substances in Electrical and Electronic Equipment (RoHS) directive.