Analog Devices Inc./Maxim Integrated

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 VINand VOUTrange.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 VINwhile 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.ApplicationsBattery Powered SystemsPoint-of-Load SuppliesPortable – Handheld Scanners and Cameras

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 VINand VOUTrange.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 VINwhile 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.ApplicationsBattery Powered SystemsPoint-of-Load SuppliesPortable – Handheld Scanners and Cameras

The LTC3646 is a high efficiency, step-down DC/DC converter with internal high side and synchronous power FETs. It draws only 140μA typical DC supply current in Burst Mode operation at no load while maintaining output voltage regulation.The LTC3646 can supply up to a 1A load, and its combination of Burst Mode operation, integrated power switches and low quiescent current provides high efficiency over a broad range of load currents. Alternatively, it can be used in forced continuous mode for ripple sensitive applications.The LTC3646 has a wide 4.0V to 40V input range and its patented controlled on-time architecture and 0.6V reference voltage allow for large step-down ratios without the risk of output overvoltage. The frequency may be set between 200kHz and 3.0MHz with a program resistor or synchronized to an external clock.The internal soft-start, short-circuit protection and voltage rating make the LTC3646 a robust part ideal for high voltage applications.ApplicationsPoint of Load Power SupplyIntermediate Bus PowerAutomotive Applications