Features and Benefits
- 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 Load Transient Response
- Overtemperature Protected
- Low Profile (3mm × 3mm) 16-Lead QFN Package
The LTC3544B 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 Li-Ion/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 very low 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.
|Light Load Operation|
|LTC3544||Burst Mode (20mVpp), < 70uA Iq|
|LTC3544B||Pulse Skip Mode|
- Cellular Telephones
- Personal Information Appliances
- Wireless and DSL Modems
- Digital Still Cameras
- Media Players
- Portable Instruments
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.