Linear Technology Debuts LTC3729 DC/DC Controller

Linear Technology Corp. (Milpitas, CA) introduced the LTC3729, a PolyPhase, scalable (modular), dc/dc, step-down controller with integrated MOSFET drivers in a new and smaller 5mm x 5mm quad-flat, no-lead package. The LTC3729 allows multiple LTC3729's to operate as one power supply in 4, 6, 8 and up to 12 phases capable of delivering load currents as high as 240A.

Each LTC3729 can deliver 35A to 40A of load current. In addition to a smaller package and minimal capacitor requirements, at 550kHz operating frequency, the LTC3729 uses half the inductance value of similar 200kHz dc/dc controllers, according to the company. The LTC3729's input voltage range is from 4V to 36V, with an output voltage adjustable from 0.8V to 5V. Applications include high-power, high-efficiency, compact power supply designs for servers, industrial systems and network processor boards.

The LTC3729 integrates both the controller section of the power supply and MOSFET drivers, driving n-channel, external-power MOSFET stages in a phase-lockable, fixed-frequency architecture. The PolyPhase controller drives its two output stages out of phase at frequencies up to 550kHz (1.1MHz effective frequency), with two phases to minimize the RMS ripple currents in both input and output capacitors. The effective frequency for a four-phase operation is 2.2MHz, and a 12-phase is 6.6MHz. The LTC3729UH is guaranteed to operate from -40 to +85 degrees C.

Pricing for the 1,000-piece quantity begins at $6.30 each.