Quad 17V, 1.25A Parallelable Synchronous Step-Down Regulator with Ultralow Quiescent Current

The LTC3644/LTC3644-2 is a quad 1.25A output, high efficiency synchronous monolithic step-down regulator capable of operating from input supplies up to 17V. The switching frequency is internally fixed to 1MHz or 2.25MHz with a ±50% synchronization range. The regulator features ultralow quiescent current and high efficiency over a wide VIN and VOUT range.

The step-down regulator operates from an input voltage range of 2.7V to 17V and provides an adjustable output range from 0.6V to VIN while delivering up to 1.25A of output current per channel. LTC3644/LTC3644-2 can be configured for quad 1.25A outputs, triple 2.5A/1.25A/1.25A outputs, dual 2.5A outputs, or dual 3.75A/1.25A outputs. A user selectable mode input is provided to allow the user to trade off ripple noise for light load efficiency; Burst Mode® operation provides the highest efficiency at light loads, while forced-continuous mode provides the lowest ripple noise. The regulators can be synchronized to an external clock.

Applications

* Battery Powered Systems

* Point-of-Load Supplies

* Portable – Handheld Scanners and Cameras

* Quad Step-down Outputs: 1.25A per Channel

* Wide VIN Range: 2.7V to 17V

* Wide VOUT Range: 0.6V to VIN

* 1.25A/2.5A/3.75A/5A IOUT Configurable with One Inductor

* Integrated 300mΩ P-Channel/80mΩ N-Channel MOSFETs Provide Up to 93% Efficiency

* No-Load Burst Mode Operation IQ < 10µA with All Channels Enabled