Date: 13/09/2008

New triple output synchronous step-down DC/DC Controller from Linear

Linear Technology Corporation launched the new LTC3853, triple output synchronous step-down switching regulator controller with coincident or ratiometric tracking that safely powers pre-biased loads. The input range of the device is 4.5V to 24V, which helps to find a wide variety of applications including most intermediate bus voltages. The on-board gate drivers of this device is able to power all N-channel MOSFET stages that can produce output currents up to 20A per phase.

Features of this controller include:

1. Constant-frequency current mode architecture allows a selectable, fixed or PLL frequency from 250kHz to 750kHz.
2. Power loss and supply noise are minimized by operating the three stages 120° out-of-phase.
3. Can also be operated in a 2+1 configuration, with output stages 1 and 2 180° out of phase.
4. Output current sensing is accomplished by measuring the voltage drop across the output inductor or by using a sense resistor.
5. Current "fold-back" limits MOSFET heat dissipation during short-circuit and overload conditions.
6. Has Programmable soft-start to control the turn-on time.
7. Selectable Burst Mode, Pulse Skip, or Forced Continuous Operating Modes to optimize light load efficiency vs. output ripple.
8. Features a precision 0.8V reference with an accuracy of ±1% over a -40°C to +125°C operating temperature range.
9. The device has a very low dropout voltage with up to 98% duty cycle, a useful feature in battery- powered applications.
10. On-Board 5V Linear Regulator
11. Power Good Signal

Applications include point-of-load regulation in datacom, telecom, set-top boxes, base-stations, and multifunction printers, where multiple voltage rails must deliver high power with low heat dissipation in a small solution size.

Package: thermally enhanced 6mm x 6mm QFN-40 package.
Price: begins at $3.53 each for 1K-piece quantities.

For further information visit: http://www.linear.com