Quad Synchronous Step-Down DC/DC Converter Provides Independent 300 mA, 2 x 200 mA and 100 mA Outputs
Linear Technology’s LTC3544 quad channel, high efficiency, 2.25 MHz, synchronous buck regulator provides up to 300 mA, dual 200 mA and 100 mA continuous outputs from a 3 mm x 3 mm QFN package. Using a constant frequency current mode architecture, the LTC3544 operates from an input voltage range of 2.25V to 5.5V, making it suitable for single-cell Li-Ion/polymer, or multicell alkaline/NiCad/NiMH applications. It can generate output voltages as low as 0.8V, enabling it to power the latest generation of low voltage DSPs and microcontrollers. Its 2.25 MHz switching frequency enables the use of tiny, low cost ceramic capacitors and inductors less than a 1 mm in height. The LTC3544’s Burst Mode operation minimizes quiescent current to 70 µA total for all four channels under no load conditions. For applications that require the lowest noise possible, the LTC3544B uses a pulse skipping mode in lieu of Burst Mode operation for lowest output ripple.