95% efficient dc/dc converter delivers up to 1A

Linear Technology Corporation has launched a converter that can deliver up to 1A of output current at efficiencies as high as 95%. The LTC3441 is a synchronous, fixed frequency, buck-boost dc/dc converter designed to optimize battery-run time for single-cell Li-Ion, multi-cell alkaline or NiMH battery-powered applications. It operates from an input voltage range of 2.4 to 5.5V and can provide up to 1A of output current at a fixed output voltage between 2.4 and 5.25V.

Its buck-boost topology allows it to operate above, below and equal to the output voltage with a single inductor, providing a continuous transfer function through all the operating modes, as the battery voltage declines. The operating frequency is set internally to 1MHz and can be synchronized up to 2MHz, allowing the use of tiny surface mount components and maintaining the switching noise well above the pass-band of most communication systems. The small implementation footprint makes it ideal for space-constrained environments such as cellular phones, PDAs, wireless and DSL modems, and digital cameras.

The LTC3441 uses two 0.10½ N-channel and two 0.11½P-channel switches in a constant frequency, synchronous switching topology to obtain efficiencies as high as 95%. Its selectable burst mode operation allows the internal power MOSFETs to operate intermittently based on load demand and reduces the quiescent current to a low 25mA when there is no load (less than 1mA in shutdown).

The LTC3441 features anti-ringing control to minimize EMI, soft-start control and thermal shutdown. It comes in a 433mm DFN package. $3.55 (1000).

Linear Technology
Fax 65-6754-4113
www.linear.com