Analog Devices LTC3544

Description

The LTC®3544B is a quad, high efficiency, monolithic synchronous buck regulator using a constant frequency, current mode architecture. The four regulators operate independently with separate run pins. The 2.25V to 5.5V input voltage range makes the LTC3544B well suited for single LiIon/polymer battery-powered applications. 100% duty cycle provides low dropout operation, extending battery runtime in portable systems. At moderate and low output load levels PWM pulse skip mode operation provides verylow output ripple voltage for noise sensitive applications.Switching frequency is internally set to 2.25MHz, allowing the use of small surface mount inductors and capacitors.The internal synchronous switches increase efficiency and eliminate the need for external Schottky diodes. Low output voltages are easily supported with the 0.8V feedback reference voltage.The LTC3544B is available in a low profile (0.75mm) (3mm × 3mm) QFN package.

Features

• High Efficiency: Up to 95%
• Four Independent Regulators Provide Up to 300mA,200mA, 200mA and 100mA Output Current
• 2.25V to 5.5V Input Voltage Range
• 2.25MHz Constant Frequency Operation
• No Schottky Diodes Required
• Low Dropout Operation: 100% Duty Cycle
• Pulse Skipping at Low Load for Minimum Ripple
• 0.8V Reference Allows Low Output Voltages
• Shutdown Mode Draws <1μA Supply Current
• Current Mode Operation for Excellent Line and LoadTransient Response
• Overtemperature Protected
• Low Profile (3mm × 3mm) 16-Lead QFN Package

Typical applications

• Media Players
• Portable Instruments
• Wireless and DSL Modems
• Personal Information Appliances
• Cellular Telephones
• Digital Still Cameras

More information

• Datasheet
• IC product information