Milpitas, Calif. - Linear Technology Corp.'s LTC3441 is a true buck-boost dc/dc converter that can deliver up to 1 amp of output current at efficiencies as high as 95 percent. The synchronous, fixed-frequency converter is designed to optimize battery run-time for single-cell lithium-ion, multicell alkaline or nickel metal hydride battery-powered applications. It operates from an input voltage range of 2.4 to 5.5 V and can provide up to 1 A of output current at a fixed output voltage between 2.4 and 5.25 V.
A unique buck-boost topology allows the LTC3441 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 1 MHz and can be synchronized up to 2 MHz, allowing the use of tiny surface-mount components and maintaining the switching noise well above the passband of most communication systems.
A small footprint suits the device for space-constrained environments such as cell phones, PDAs, wireless and DSL modems, and digital cameras.
The LTC3441 uses two 0.1-ohm n-channel and two 0.11- ohms p-channel switches in a constant-frequency, synchronous switching topology to obtain efficiencies as high as 95 percent. Selectable burst-mode operation allows the internal power MOSFETs to operate intermittently based on load demand and reduces the quiescent current to 25 microamps when there is no load (less than 1 microamps in shutdown). The LTC3441 also features anti-ringing control, to minimize electromagnetic interference; soft-start control; and thermal shutdown.
The LTC3441 comes in a low-profile 4 x 3-mm package, which is about half the size of typical buck-and-boost designs. It operates at a 1-MHz fixed frequency and needs few external components, including two to three capacitors, two or three resistors and one inductor. No Schottky diodes are required.
The LTC3441 is available from stock, priced starting at $3.55 each in quantities of 1,000 pieces.
Call (408) 432-1900