Linear Tech Releases I²C Controlled 4-Output Synchronous Step-Down DC-DC Converter
Linear Technology announced the LTC3562, a quad channel, 2.25 MHz, synchronous buck converter that can deliver dual 600mA and dual 400mA continuous outputs from a 3 x 3mm QFN package. Using a constant frequency current mode architecture, the LTC3562 operates from an input voltage range of 2.7 to 5.5V, making it suitable for single cell Li-Ion/polymer, or multicell alkaline/NiCad/NiMH applications. The LTC3562 has two channels (600 and 400mA) that allow the output voltage to be adjusted by programming the feedback voltages between 425 and 800mV in 25mV increments.
The other two channels (600 and 400mA) feature fixed outputs that can be programmed between 600mV and 3.775V in 25mV steps. Programming is done on an I²C interface. This level of independent output voltage control makes the LTC3562 suitable for managing multiple supply rails. Its 2.25MHz switching frequency enables the utilization of tiny, ceramic capacitors and inductors less than a 1mm in height. This, combined with a 3 x 3mm QFN package, is said to provide a very compact quad output solution for handheld and other dense board applications.
The LTC3562 delivers up to 96% efficiency and its LDO mode operation minimizes quiescent current to only 100µA in no load conditions while minimizing noise. The LTC3562 can also be programmed to use Burst Mode®, pulse skipping or continuous mode operation in lieu of the LDO mode. The LTC3562 also utilizes low dropout 100% duty cycle operation to allow output voltages up to VIN, further extending battery run-time. Each channel has internal soft-start and independent enable and mode control, enhancing design flexibility. Other features include short-circuit protection and over-temperature protection.
The LTC3562EUD is available from stock in a 20-lead 3 x 3mm QFN package. Pricing starts at $3.50 each in 1,000-piece quantities.
